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1131cb0ef41Sopenharmony_ci          <ul>
1141cb0ef41Sopenharmony_ci            <li class="pinned-header">Node.js v18.20.1</li>
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1181cb0ef41Sopenharmony_ci        <span class="collapsed-arrow">&#x25ba;</span><span class="expanded-arrow">&#x25bc;</span>
1191cb0ef41Sopenharmony_ci        Table of contents
1201cb0ef41Sopenharmony_ci      </a>
1211cb0ef41Sopenharmony_ci
1221cb0ef41Sopenharmony_ci      <div class="picker"><div class="toc"><ul>
1231cb0ef41Sopenharmony_ci<li><span class="stability_1"><a href="#test-runner">Test runner</a></span>
1241cb0ef41Sopenharmony_ci<ul>
1251cb0ef41Sopenharmony_ci<li><a href="#subtests">Subtests</a></li>
1261cb0ef41Sopenharmony_ci<li><a href="#skipping-tests">Skipping tests</a></li>
1271cb0ef41Sopenharmony_ci<li><a href="#describeit-syntax"><code>describe</code>/<code>it</code> syntax</a></li>
1281cb0ef41Sopenharmony_ci<li><a href="#only-tests"><code>only</code> tests</a></li>
1291cb0ef41Sopenharmony_ci<li><a href="#filtering-tests-by-name">Filtering tests by name</a></li>
1301cb0ef41Sopenharmony_ci<li><a href="#extraneous-asynchronous-activity">Extraneous asynchronous activity</a></li>
1311cb0ef41Sopenharmony_ci<li><span class="stability_1"><a href="#watch-mode">Watch mode</a></span></li>
1321cb0ef41Sopenharmony_ci<li><a href="#running-tests-from-the-command-line">Running tests from the command line</a>
1331cb0ef41Sopenharmony_ci<ul>
1341cb0ef41Sopenharmony_ci<li><a href="#test-runner-execution-model">Test runner execution model</a></li>
1351cb0ef41Sopenharmony_ci</ul>
1361cb0ef41Sopenharmony_ci</li>
1371cb0ef41Sopenharmony_ci<li><a href="#collecting-code-coverage">Collecting code coverage</a></li>
1381cb0ef41Sopenharmony_ci<li><a href="#mocking">Mocking</a>
1391cb0ef41Sopenharmony_ci<ul>
1401cb0ef41Sopenharmony_ci<li><a href="#timers">Timers</a></li>
1411cb0ef41Sopenharmony_ci</ul>
1421cb0ef41Sopenharmony_ci</li>
1431cb0ef41Sopenharmony_ci<li><a href="#test-reporters">Test reporters</a>
1441cb0ef41Sopenharmony_ci<ul>
1451cb0ef41Sopenharmony_ci<li><a href="#custom-reporters">Custom reporters</a></li>
1461cb0ef41Sopenharmony_ci<li><a href="#multiple-reporters">Multiple reporters</a></li>
1471cb0ef41Sopenharmony_ci</ul>
1481cb0ef41Sopenharmony_ci</li>
1491cb0ef41Sopenharmony_ci<li><a href="#runoptions"><code>run([options])</code></a></li>
1501cb0ef41Sopenharmony_ci<li><a href="#testname-options-fn"><code>test([name][, options][, fn])</code></a></li>
1511cb0ef41Sopenharmony_ci<li><a href="#testskipname-options-fn"><code>test.skip([name][, options][, fn])</code></a></li>
1521cb0ef41Sopenharmony_ci<li><a href="#testtodoname-options-fn"><code>test.todo([name][, options][, fn])</code></a></li>
1531cb0ef41Sopenharmony_ci<li><a href="#testonlyname-options-fn"><code>test.only([name][, options][, fn])</code></a></li>
1541cb0ef41Sopenharmony_ci<li><a href="#describename-options-fn"><code>describe([name][, options][, fn])</code></a></li>
1551cb0ef41Sopenharmony_ci<li><a href="#describeskipname-options-fn"><code>describe.skip([name][, options][, fn])</code></a></li>
1561cb0ef41Sopenharmony_ci<li><a href="#describetodoname-options-fn"><code>describe.todo([name][, options][, fn])</code></a></li>
1571cb0ef41Sopenharmony_ci<li><a href="#describeonlyname-options-fn"><code>describe.only([name][, options][, fn])</code></a></li>
1581cb0ef41Sopenharmony_ci<li><a href="#itname-options-fn"><code>it([name][, options][, fn])</code></a></li>
1591cb0ef41Sopenharmony_ci<li><a href="#itskipname-options-fn"><code>it.skip([name][, options][, fn])</code></a></li>
1601cb0ef41Sopenharmony_ci<li><a href="#ittodoname-options-fn"><code>it.todo([name][, options][, fn])</code></a></li>
1611cb0ef41Sopenharmony_ci<li><a href="#itonlyname-options-fn"><code>it.only([name][, options][, fn])</code></a></li>
1621cb0ef41Sopenharmony_ci<li><a href="#beforefn-options"><code>before([fn][, options])</code></a></li>
1631cb0ef41Sopenharmony_ci<li><a href="#afterfn-options"><code>after([fn][, options])</code></a></li>
1641cb0ef41Sopenharmony_ci<li><a href="#beforeeachfn-options"><code>beforeEach([fn][, options])</code></a></li>
1651cb0ef41Sopenharmony_ci<li><a href="#aftereachfn-options"><code>afterEach([fn][, options])</code></a></li>
1661cb0ef41Sopenharmony_ci<li><a href="#class-mockfunctioncontext">Class: <code>MockFunctionContext</code></a>
1671cb0ef41Sopenharmony_ci<ul>
1681cb0ef41Sopenharmony_ci<li><a href="#ctxcalls"><code>ctx.calls</code></a></li>
1691cb0ef41Sopenharmony_ci<li><a href="#ctxcallcount"><code>ctx.callCount()</code></a></li>
1701cb0ef41Sopenharmony_ci<li><a href="#ctxmockimplementationimplementation"><code>ctx.mockImplementation(implementation)</code></a></li>
1711cb0ef41Sopenharmony_ci<li><a href="#ctxmockimplementationonceimplementation-oncall"><code>ctx.mockImplementationOnce(implementation[, onCall])</code></a></li>
1721cb0ef41Sopenharmony_ci<li><a href="#ctxresetcalls"><code>ctx.resetCalls()</code></a></li>
1731cb0ef41Sopenharmony_ci<li><a href="#ctxrestore"><code>ctx.restore()</code></a></li>
1741cb0ef41Sopenharmony_ci</ul>
1751cb0ef41Sopenharmony_ci</li>
1761cb0ef41Sopenharmony_ci<li><a href="#class-mocktracker">Class: <code>MockTracker</code></a>
1771cb0ef41Sopenharmony_ci<ul>
1781cb0ef41Sopenharmony_ci<li><a href="#mockfnoriginal-implementation-options"><code>mock.fn([original[, implementation]][, options])</code></a></li>
1791cb0ef41Sopenharmony_ci<li><a href="#mockgetterobject-methodname-implementation-options"><code>mock.getter(object, methodName[, implementation][, options])</code></a></li>
1801cb0ef41Sopenharmony_ci<li><a href="#mockmethodobject-methodname-implementation-options"><code>mock.method(object, methodName[, implementation][, options])</code></a></li>
1811cb0ef41Sopenharmony_ci<li><a href="#mockreset"><code>mock.reset()</code></a></li>
1821cb0ef41Sopenharmony_ci<li><a href="#mockrestoreall"><code>mock.restoreAll()</code></a></li>
1831cb0ef41Sopenharmony_ci<li><a href="#mocksetterobject-methodname-implementation-options"><code>mock.setter(object, methodName[, implementation][, options])</code></a></li>
1841cb0ef41Sopenharmony_ci</ul>
1851cb0ef41Sopenharmony_ci</li>
1861cb0ef41Sopenharmony_ci<li><span class="stability_1"><a href="#class-mocktimers">Class: <code>MockTimers</code></a></span>
1871cb0ef41Sopenharmony_ci<ul>
1881cb0ef41Sopenharmony_ci<li><a href="#timersenabletimers"><code>timers.enable([timers])</code></a></li>
1891cb0ef41Sopenharmony_ci<li><a href="#timersreset"><code>timers.reset()</code></a></li>
1901cb0ef41Sopenharmony_ci<li><a href="#timerssymboldispose"><code>timers[Symbol.dispose]()</code></a></li>
1911cb0ef41Sopenharmony_ci<li><a href="#timerstickmilliseconds"><code>timers.tick(milliseconds)</code></a>
1921cb0ef41Sopenharmony_ci<ul>
1931cb0ef41Sopenharmony_ci<li><a href="#using-clear-functions">Using clear functions</a></li>
1941cb0ef41Sopenharmony_ci<li><a href="#working-with-nodejs-timers-modules">Working with Node.js timers modules</a></li>
1951cb0ef41Sopenharmony_ci</ul>
1961cb0ef41Sopenharmony_ci</li>
1971cb0ef41Sopenharmony_ci<li><a href="#timersrunall"><code>timers.runAll()</code></a></li>
1981cb0ef41Sopenharmony_ci</ul>
1991cb0ef41Sopenharmony_ci</li>
2001cb0ef41Sopenharmony_ci<li><a href="#class-testsstream">Class: <code>TestsStream</code></a>
2011cb0ef41Sopenharmony_ci<ul>
2021cb0ef41Sopenharmony_ci<li><a href="#event-testcoverage">Event: <code>'test:coverage'</code></a></li>
2031cb0ef41Sopenharmony_ci<li><a href="#event-testdequeue">Event: <code>'test:dequeue'</code></a></li>
2041cb0ef41Sopenharmony_ci<li><a href="#event-testdiagnostic">Event: <code>'test:diagnostic'</code></a></li>
2051cb0ef41Sopenharmony_ci<li><a href="#event-testenqueue">Event: <code>'test:enqueue'</code></a></li>
2061cb0ef41Sopenharmony_ci<li><a href="#event-testfail">Event: <code>'test:fail'</code></a></li>
2071cb0ef41Sopenharmony_ci<li><a href="#event-testpass">Event: <code>'test:pass'</code></a></li>
2081cb0ef41Sopenharmony_ci<li><a href="#event-testplan">Event: <code>'test:plan'</code></a></li>
2091cb0ef41Sopenharmony_ci<li><a href="#event-teststart">Event: <code>'test:start'</code></a></li>
2101cb0ef41Sopenharmony_ci<li><a href="#event-teststderr">Event: <code>'test:stderr'</code></a></li>
2111cb0ef41Sopenharmony_ci<li><a href="#event-teststdout">Event: <code>'test:stdout'</code></a></li>
2121cb0ef41Sopenharmony_ci<li><a href="#event-testwatchdrained">Event: <code>'test:watch:drained'</code></a></li>
2131cb0ef41Sopenharmony_ci</ul>
2141cb0ef41Sopenharmony_ci</li>
2151cb0ef41Sopenharmony_ci<li><a href="#class-testcontext">Class: <code>TestContext</code></a>
2161cb0ef41Sopenharmony_ci<ul>
2171cb0ef41Sopenharmony_ci<li><a href="#contextbeforefn-options"><code>context.before([fn][, options])</code></a></li>
2181cb0ef41Sopenharmony_ci<li><a href="#contextbeforeeachfn-options"><code>context.beforeEach([fn][, options])</code></a></li>
2191cb0ef41Sopenharmony_ci<li><a href="#contextafterfn-options"><code>context.after([fn][, options])</code></a></li>
2201cb0ef41Sopenharmony_ci<li><a href="#contextaftereachfn-options"><code>context.afterEach([fn][, options])</code></a></li>
2211cb0ef41Sopenharmony_ci<li><a href="#contextdiagnosticmessage"><code>context.diagnostic(message)</code></a></li>
2221cb0ef41Sopenharmony_ci<li><a href="#contextname"><code>context.name</code></a></li>
2231cb0ef41Sopenharmony_ci<li><a href="#contextrunonlyshouldrunonlytests"><code>context.runOnly(shouldRunOnlyTests)</code></a></li>
2241cb0ef41Sopenharmony_ci<li><a href="#contextsignal"><code>context.signal</code></a></li>
2251cb0ef41Sopenharmony_ci<li><a href="#contextskipmessage"><code>context.skip([message])</code></a></li>
2261cb0ef41Sopenharmony_ci<li><a href="#contexttodomessage"><code>context.todo([message])</code></a></li>
2271cb0ef41Sopenharmony_ci<li><a href="#contexttestname-options-fn"><code>context.test([name][, options][, fn])</code></a></li>
2281cb0ef41Sopenharmony_ci</ul>
2291cb0ef41Sopenharmony_ci</li>
2301cb0ef41Sopenharmony_ci<li><a href="#class-suitecontext">Class: <code>SuiteContext</code></a>
2311cb0ef41Sopenharmony_ci<ul>
2321cb0ef41Sopenharmony_ci<li><a href="#contextname_1"><code>context.name</code></a></li>
2331cb0ef41Sopenharmony_ci<li><a href="#contextsignal_1"><code>context.signal</code></a></li>
2341cb0ef41Sopenharmony_ci</ul>
2351cb0ef41Sopenharmony_ci</li>
2361cb0ef41Sopenharmony_ci</ul>
2371cb0ef41Sopenharmony_ci</li>
2381cb0ef41Sopenharmony_ci</ul></div></div>
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2451cb0ef41Sopenharmony_ci        Index
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3451cb0ef41Sopenharmony_ci                <ul>
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3501cb0ef41Sopenharmony_ci                    <a href="test.json">View as JSON</a>
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3521cb0ef41Sopenharmony_ci                  <li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/main/doc/api/test.md">Edit on GitHub</a></li>    
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3551cb0ef41Sopenharmony_ci            </li>
3561cb0ef41Sopenharmony_ci          </ul>
3571cb0ef41Sopenharmony_ci        </div>
3581cb0ef41Sopenharmony_ci        <hr>
3591cb0ef41Sopenharmony_ci      </header>
3601cb0ef41Sopenharmony_ci
3611cb0ef41Sopenharmony_ci      <details id="toc" open><summary>Table of contents</summary><ul>
3621cb0ef41Sopenharmony_ci<li><span class="stability_1"><a href="#test-runner">Test runner</a></span>
3631cb0ef41Sopenharmony_ci<ul>
3641cb0ef41Sopenharmony_ci<li><a href="#subtests">Subtests</a></li>
3651cb0ef41Sopenharmony_ci<li><a href="#skipping-tests">Skipping tests</a></li>
3661cb0ef41Sopenharmony_ci<li><a href="#describeit-syntax"><code>describe</code>/<code>it</code> syntax</a></li>
3671cb0ef41Sopenharmony_ci<li><a href="#only-tests"><code>only</code> tests</a></li>
3681cb0ef41Sopenharmony_ci<li><a href="#filtering-tests-by-name">Filtering tests by name</a></li>
3691cb0ef41Sopenharmony_ci<li><a href="#extraneous-asynchronous-activity">Extraneous asynchronous activity</a></li>
3701cb0ef41Sopenharmony_ci<li><span class="stability_1"><a href="#watch-mode">Watch mode</a></span></li>
3711cb0ef41Sopenharmony_ci<li><a href="#running-tests-from-the-command-line">Running tests from the command line</a>
3721cb0ef41Sopenharmony_ci<ul>
3731cb0ef41Sopenharmony_ci<li><a href="#test-runner-execution-model">Test runner execution model</a></li>
3741cb0ef41Sopenharmony_ci</ul>
3751cb0ef41Sopenharmony_ci</li>
3761cb0ef41Sopenharmony_ci<li><a href="#collecting-code-coverage">Collecting code coverage</a></li>
3771cb0ef41Sopenharmony_ci<li><a href="#mocking">Mocking</a>
3781cb0ef41Sopenharmony_ci<ul>
3791cb0ef41Sopenharmony_ci<li><a href="#timers">Timers</a></li>
3801cb0ef41Sopenharmony_ci</ul>
3811cb0ef41Sopenharmony_ci</li>
3821cb0ef41Sopenharmony_ci<li><a href="#test-reporters">Test reporters</a>
3831cb0ef41Sopenharmony_ci<ul>
3841cb0ef41Sopenharmony_ci<li><a href="#custom-reporters">Custom reporters</a></li>
3851cb0ef41Sopenharmony_ci<li><a href="#multiple-reporters">Multiple reporters</a></li>
3861cb0ef41Sopenharmony_ci</ul>
3871cb0ef41Sopenharmony_ci</li>
3881cb0ef41Sopenharmony_ci<li><a href="#runoptions"><code>run([options])</code></a></li>
3891cb0ef41Sopenharmony_ci<li><a href="#testname-options-fn"><code>test([name][, options][, fn])</code></a></li>
3901cb0ef41Sopenharmony_ci<li><a href="#testskipname-options-fn"><code>test.skip([name][, options][, fn])</code></a></li>
3911cb0ef41Sopenharmony_ci<li><a href="#testtodoname-options-fn"><code>test.todo([name][, options][, fn])</code></a></li>
3921cb0ef41Sopenharmony_ci<li><a href="#testonlyname-options-fn"><code>test.only([name][, options][, fn])</code></a></li>
3931cb0ef41Sopenharmony_ci<li><a href="#describename-options-fn"><code>describe([name][, options][, fn])</code></a></li>
3941cb0ef41Sopenharmony_ci<li><a href="#describeskipname-options-fn"><code>describe.skip([name][, options][, fn])</code></a></li>
3951cb0ef41Sopenharmony_ci<li><a href="#describetodoname-options-fn"><code>describe.todo([name][, options][, fn])</code></a></li>
3961cb0ef41Sopenharmony_ci<li><a href="#describeonlyname-options-fn"><code>describe.only([name][, options][, fn])</code></a></li>
3971cb0ef41Sopenharmony_ci<li><a href="#itname-options-fn"><code>it([name][, options][, fn])</code></a></li>
3981cb0ef41Sopenharmony_ci<li><a href="#itskipname-options-fn"><code>it.skip([name][, options][, fn])</code></a></li>
3991cb0ef41Sopenharmony_ci<li><a href="#ittodoname-options-fn"><code>it.todo([name][, options][, fn])</code></a></li>
4001cb0ef41Sopenharmony_ci<li><a href="#itonlyname-options-fn"><code>it.only([name][, options][, fn])</code></a></li>
4011cb0ef41Sopenharmony_ci<li><a href="#beforefn-options"><code>before([fn][, options])</code></a></li>
4021cb0ef41Sopenharmony_ci<li><a href="#afterfn-options"><code>after([fn][, options])</code></a></li>
4031cb0ef41Sopenharmony_ci<li><a href="#beforeeachfn-options"><code>beforeEach([fn][, options])</code></a></li>
4041cb0ef41Sopenharmony_ci<li><a href="#aftereachfn-options"><code>afterEach([fn][, options])</code></a></li>
4051cb0ef41Sopenharmony_ci<li><a href="#class-mockfunctioncontext">Class: <code>MockFunctionContext</code></a>
4061cb0ef41Sopenharmony_ci<ul>
4071cb0ef41Sopenharmony_ci<li><a href="#ctxcalls"><code>ctx.calls</code></a></li>
4081cb0ef41Sopenharmony_ci<li><a href="#ctxcallcount"><code>ctx.callCount()</code></a></li>
4091cb0ef41Sopenharmony_ci<li><a href="#ctxmockimplementationimplementation"><code>ctx.mockImplementation(implementation)</code></a></li>
4101cb0ef41Sopenharmony_ci<li><a href="#ctxmockimplementationonceimplementation-oncall"><code>ctx.mockImplementationOnce(implementation[, onCall])</code></a></li>
4111cb0ef41Sopenharmony_ci<li><a href="#ctxresetcalls"><code>ctx.resetCalls()</code></a></li>
4121cb0ef41Sopenharmony_ci<li><a href="#ctxrestore"><code>ctx.restore()</code></a></li>
4131cb0ef41Sopenharmony_ci</ul>
4141cb0ef41Sopenharmony_ci</li>
4151cb0ef41Sopenharmony_ci<li><a href="#class-mocktracker">Class: <code>MockTracker</code></a>
4161cb0ef41Sopenharmony_ci<ul>
4171cb0ef41Sopenharmony_ci<li><a href="#mockfnoriginal-implementation-options"><code>mock.fn([original[, implementation]][, options])</code></a></li>
4181cb0ef41Sopenharmony_ci<li><a href="#mockgetterobject-methodname-implementation-options"><code>mock.getter(object, methodName[, implementation][, options])</code></a></li>
4191cb0ef41Sopenharmony_ci<li><a href="#mockmethodobject-methodname-implementation-options"><code>mock.method(object, methodName[, implementation][, options])</code></a></li>
4201cb0ef41Sopenharmony_ci<li><a href="#mockreset"><code>mock.reset()</code></a></li>
4211cb0ef41Sopenharmony_ci<li><a href="#mockrestoreall"><code>mock.restoreAll()</code></a></li>
4221cb0ef41Sopenharmony_ci<li><a href="#mocksetterobject-methodname-implementation-options"><code>mock.setter(object, methodName[, implementation][, options])</code></a></li>
4231cb0ef41Sopenharmony_ci</ul>
4241cb0ef41Sopenharmony_ci</li>
4251cb0ef41Sopenharmony_ci<li><span class="stability_1"><a href="#class-mocktimers">Class: <code>MockTimers</code></a></span>
4261cb0ef41Sopenharmony_ci<ul>
4271cb0ef41Sopenharmony_ci<li><a href="#timersenabletimers"><code>timers.enable([timers])</code></a></li>
4281cb0ef41Sopenharmony_ci<li><a href="#timersreset"><code>timers.reset()</code></a></li>
4291cb0ef41Sopenharmony_ci<li><a href="#timerssymboldispose"><code>timers[Symbol.dispose]()</code></a></li>
4301cb0ef41Sopenharmony_ci<li><a href="#timerstickmilliseconds"><code>timers.tick(milliseconds)</code></a>
4311cb0ef41Sopenharmony_ci<ul>
4321cb0ef41Sopenharmony_ci<li><a href="#using-clear-functions">Using clear functions</a></li>
4331cb0ef41Sopenharmony_ci<li><a href="#working-with-nodejs-timers-modules">Working with Node.js timers modules</a></li>
4341cb0ef41Sopenharmony_ci</ul>
4351cb0ef41Sopenharmony_ci</li>
4361cb0ef41Sopenharmony_ci<li><a href="#timersrunall"><code>timers.runAll()</code></a></li>
4371cb0ef41Sopenharmony_ci</ul>
4381cb0ef41Sopenharmony_ci</li>
4391cb0ef41Sopenharmony_ci<li><a href="#class-testsstream">Class: <code>TestsStream</code></a>
4401cb0ef41Sopenharmony_ci<ul>
4411cb0ef41Sopenharmony_ci<li><a href="#event-testcoverage">Event: <code>'test:coverage'</code></a></li>
4421cb0ef41Sopenharmony_ci<li><a href="#event-testdequeue">Event: <code>'test:dequeue'</code></a></li>
4431cb0ef41Sopenharmony_ci<li><a href="#event-testdiagnostic">Event: <code>'test:diagnostic'</code></a></li>
4441cb0ef41Sopenharmony_ci<li><a href="#event-testenqueue">Event: <code>'test:enqueue'</code></a></li>
4451cb0ef41Sopenharmony_ci<li><a href="#event-testfail">Event: <code>'test:fail'</code></a></li>
4461cb0ef41Sopenharmony_ci<li><a href="#event-testpass">Event: <code>'test:pass'</code></a></li>
4471cb0ef41Sopenharmony_ci<li><a href="#event-testplan">Event: <code>'test:plan'</code></a></li>
4481cb0ef41Sopenharmony_ci<li><a href="#event-teststart">Event: <code>'test:start'</code></a></li>
4491cb0ef41Sopenharmony_ci<li><a href="#event-teststderr">Event: <code>'test:stderr'</code></a></li>
4501cb0ef41Sopenharmony_ci<li><a href="#event-teststdout">Event: <code>'test:stdout'</code></a></li>
4511cb0ef41Sopenharmony_ci<li><a href="#event-testwatchdrained">Event: <code>'test:watch:drained'</code></a></li>
4521cb0ef41Sopenharmony_ci</ul>
4531cb0ef41Sopenharmony_ci</li>
4541cb0ef41Sopenharmony_ci<li><a href="#class-testcontext">Class: <code>TestContext</code></a>
4551cb0ef41Sopenharmony_ci<ul>
4561cb0ef41Sopenharmony_ci<li><a href="#contextbeforefn-options"><code>context.before([fn][, options])</code></a></li>
4571cb0ef41Sopenharmony_ci<li><a href="#contextbeforeeachfn-options"><code>context.beforeEach([fn][, options])</code></a></li>
4581cb0ef41Sopenharmony_ci<li><a href="#contextafterfn-options"><code>context.after([fn][, options])</code></a></li>
4591cb0ef41Sopenharmony_ci<li><a href="#contextaftereachfn-options"><code>context.afterEach([fn][, options])</code></a></li>
4601cb0ef41Sopenharmony_ci<li><a href="#contextdiagnosticmessage"><code>context.diagnostic(message)</code></a></li>
4611cb0ef41Sopenharmony_ci<li><a href="#contextname"><code>context.name</code></a></li>
4621cb0ef41Sopenharmony_ci<li><a href="#contextrunonlyshouldrunonlytests"><code>context.runOnly(shouldRunOnlyTests)</code></a></li>
4631cb0ef41Sopenharmony_ci<li><a href="#contextsignal"><code>context.signal</code></a></li>
4641cb0ef41Sopenharmony_ci<li><a href="#contextskipmessage"><code>context.skip([message])</code></a></li>
4651cb0ef41Sopenharmony_ci<li><a href="#contexttodomessage"><code>context.todo([message])</code></a></li>
4661cb0ef41Sopenharmony_ci<li><a href="#contexttestname-options-fn"><code>context.test([name][, options][, fn])</code></a></li>
4671cb0ef41Sopenharmony_ci</ul>
4681cb0ef41Sopenharmony_ci</li>
4691cb0ef41Sopenharmony_ci<li><a href="#class-suitecontext">Class: <code>SuiteContext</code></a>
4701cb0ef41Sopenharmony_ci<ul>
4711cb0ef41Sopenharmony_ci<li><a href="#contextname_1"><code>context.name</code></a></li>
4721cb0ef41Sopenharmony_ci<li><a href="#contextsignal_1"><code>context.signal</code></a></li>
4731cb0ef41Sopenharmony_ci</ul>
4741cb0ef41Sopenharmony_ci</li>
4751cb0ef41Sopenharmony_ci</ul>
4761cb0ef41Sopenharmony_ci</li>
4771cb0ef41Sopenharmony_ci</ul></details>
4781cb0ef41Sopenharmony_ci
4791cb0ef41Sopenharmony_ci      <div id="apicontent">
4801cb0ef41Sopenharmony_ci        <h2>Test runner<span><a class="mark" href="#test-runner" id="test-runner">#</a></span><a aria-hidden="true" class="legacy" id="test_test_runner"></a></h2>
4811cb0ef41Sopenharmony_ci
4821cb0ef41Sopenharmony_ci<div class="api_metadata">
4831cb0ef41Sopenharmony_ci<span>Added in: v18.0.0, v16.17.0</span>
4841cb0ef41Sopenharmony_ci</div>
4851cb0ef41Sopenharmony_ci<p></p><div class="api_stability api_stability_1"><a href="documentation.html#stability-index">Stability: 1</a> - Experimental</div><p></p>
4861cb0ef41Sopenharmony_ci<p><strong>Source Code:</strong> <a href="https://github.com/nodejs/node/blob/v18.20.1/lib/test.js">lib/test.js</a></p>
4871cb0ef41Sopenharmony_ci<p>The <code>node:test</code> module facilitates the creation of JavaScript tests.
4881cb0ef41Sopenharmony_ciTo access it:</p>
4891cb0ef41Sopenharmony_ci
4901cb0ef41Sopenharmony_ci<pre class="with-34-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> test <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;</code><code class="language-js cjs"><span class="hljs-keyword">const</span> test = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);</code><button class="copy-button">copy</button></pre>
4911cb0ef41Sopenharmony_ci<p>This module is only available under the <code>node:</code> scheme. The following will not
4921cb0ef41Sopenharmony_ciwork:</p>
4931cb0ef41Sopenharmony_ci
4941cb0ef41Sopenharmony_ci<pre class="with-29-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> test <span class="hljs-keyword">from</span> <span class="hljs-string">'test'</span>;</code><code class="language-js cjs"><span class="hljs-keyword">const</span> test = <span class="hljs-built_in">require</span>(<span class="hljs-string">'test'</span>);</code><button class="copy-button">copy</button></pre>
4951cb0ef41Sopenharmony_ci<p>Tests created via the <code>test</code> module consist of a single function that is
4961cb0ef41Sopenharmony_ciprocessed in one of three ways:</p>
4971cb0ef41Sopenharmony_ci<ol>
4981cb0ef41Sopenharmony_ci<li>A synchronous function that is considered failing if it throws an exception,
4991cb0ef41Sopenharmony_ciand is considered passing otherwise.</li>
5001cb0ef41Sopenharmony_ci<li>A function that returns a <code>Promise</code> that is considered failing if the
5011cb0ef41Sopenharmony_ci<code>Promise</code> rejects, and is considered passing if the <code>Promise</code> resolves.</li>
5021cb0ef41Sopenharmony_ci<li>A function that receives a callback function. If the callback receives any
5031cb0ef41Sopenharmony_citruthy value as its first argument, the test is considered failing. If a
5041cb0ef41Sopenharmony_cifalsy value is passed as the first argument to the callback, the test is
5051cb0ef41Sopenharmony_ciconsidered passing. If the test function receives a callback function and
5061cb0ef41Sopenharmony_cialso returns a <code>Promise</code>, the test will fail.</li>
5071cb0ef41Sopenharmony_ci</ol>
5081cb0ef41Sopenharmony_ci<p>The following example illustrates how tests are written using the
5091cb0ef41Sopenharmony_ci<code>test</code> module.</p>
5101cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'synchronous passing test'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5111cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This test passes because it does not throw an exception.</span>
5121cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">1</span>, <span class="hljs-number">1</span>);
5131cb0ef41Sopenharmony_ci});
5141cb0ef41Sopenharmony_ci
5151cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'synchronous failing test'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5161cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This test fails because it throws an exception.</span>
5171cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">1</span>, <span class="hljs-number">2</span>);
5181cb0ef41Sopenharmony_ci});
5191cb0ef41Sopenharmony_ci
5201cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'asynchronous passing test'</span>, <span class="hljs-keyword">async</span> (t) => {
5211cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This test passes because the Promise returned by the async</span>
5221cb0ef41Sopenharmony_ci  <span class="hljs-comment">// function is not rejected.</span>
5231cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">1</span>, <span class="hljs-number">1</span>);
5241cb0ef41Sopenharmony_ci});
5251cb0ef41Sopenharmony_ci
5261cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'asynchronous failing test'</span>, <span class="hljs-keyword">async</span> (t) => {
5271cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This test fails because the Promise returned by the async</span>
5281cb0ef41Sopenharmony_ci  <span class="hljs-comment">// function is rejected.</span>
5291cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">1</span>, <span class="hljs-number">2</span>);
5301cb0ef41Sopenharmony_ci});
5311cb0ef41Sopenharmony_ci
5321cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'failing test using Promises'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5331cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Promises can be used directly as well.</span>
5341cb0ef41Sopenharmony_ci  <span class="hljs-keyword">return</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">Promise</span>(<span class="hljs-function">(<span class="hljs-params">resolve, reject</span>) =></span> {
5351cb0ef41Sopenharmony_ci    <span class="hljs-title function_">setImmediate</span>(<span class="hljs-function">() =></span> {
5361cb0ef41Sopenharmony_ci      <span class="hljs-title function_">reject</span>(<span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'this will cause the test to fail'</span>));
5371cb0ef41Sopenharmony_ci    });
5381cb0ef41Sopenharmony_ci  });
5391cb0ef41Sopenharmony_ci});
5401cb0ef41Sopenharmony_ci
5411cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'callback passing test'</span>, <span class="hljs-function">(<span class="hljs-params">t, done</span>) =></span> {
5421cb0ef41Sopenharmony_ci  <span class="hljs-comment">// done() is the callback function. When the setImmediate() runs, it invokes</span>
5431cb0ef41Sopenharmony_ci  <span class="hljs-comment">// done() with no arguments.</span>
5441cb0ef41Sopenharmony_ci  <span class="hljs-title function_">setImmediate</span>(done);
5451cb0ef41Sopenharmony_ci});
5461cb0ef41Sopenharmony_ci
5471cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'callback failing test'</span>, <span class="hljs-function">(<span class="hljs-params">t, done</span>) =></span> {
5481cb0ef41Sopenharmony_ci  <span class="hljs-comment">// When the setImmediate() runs, done() is invoked with an Error object and</span>
5491cb0ef41Sopenharmony_ci  <span class="hljs-comment">// the test fails.</span>
5501cb0ef41Sopenharmony_ci  <span class="hljs-title function_">setImmediate</span>(<span class="hljs-function">() =></span> {
5511cb0ef41Sopenharmony_ci    <span class="hljs-title function_">done</span>(<span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'callback failure'</span>));
5521cb0ef41Sopenharmony_ci  });
5531cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
5541cb0ef41Sopenharmony_ci<p>If any tests fail, the process exit code is set to <code>1</code>.</p>
5551cb0ef41Sopenharmony_ci<section><h3>Subtests<span><a class="mark" href="#subtests" id="subtests">#</a></span><a aria-hidden="true" class="legacy" id="test_subtests"></a></h3>
5561cb0ef41Sopenharmony_ci<p>The test context's <code>test()</code> method allows subtests to be created. This method
5571cb0ef41Sopenharmony_cibehaves identically to the top level <code>test()</code> function. The following example
5581cb0ef41Sopenharmony_cidemonstrates the creation of a top level test with two subtests.</p>
5591cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
5601cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'subtest 1'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5611cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">1</span>, <span class="hljs-number">1</span>);
5621cb0ef41Sopenharmony_ci  });
5631cb0ef41Sopenharmony_ci
5641cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'subtest 2'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5651cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">2</span>, <span class="hljs-number">2</span>);
5661cb0ef41Sopenharmony_ci  });
5671cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
5681cb0ef41Sopenharmony_ci<p>In this example, <code>await</code> is used to ensure that both subtests have completed.
5691cb0ef41Sopenharmony_ciThis is necessary because parent tests do not wait for their subtests to
5701cb0ef41Sopenharmony_cicomplete. Any subtests that are still outstanding when their parent finishes
5711cb0ef41Sopenharmony_ciare cancelled and treated as failures. Any subtest failures cause the parent
5721cb0ef41Sopenharmony_citest to fail.</p>
5731cb0ef41Sopenharmony_ci</section><section><h3>Skipping tests<span><a class="mark" href="#skipping-tests" id="skipping-tests">#</a></span><a aria-hidden="true" class="legacy" id="test_skipping_tests"></a></h3>
5741cb0ef41Sopenharmony_ci<p>Individual tests can be skipped by passing the <code>skip</code> option to the test, or by
5751cb0ef41Sopenharmony_cicalling the test context's <code>skip()</code> method as shown in the
5761cb0ef41Sopenharmony_cifollowing example.</p>
5771cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-comment">// The skip option is used, but no message is provided.</span>
5781cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'skip option'</span>, { <span class="hljs-attr">skip</span>: <span class="hljs-literal">true</span> }, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5791cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This code is never executed.</span>
5801cb0ef41Sopenharmony_ci});
5811cb0ef41Sopenharmony_ci
5821cb0ef41Sopenharmony_ci<span class="hljs-comment">// The skip option is used, and a message is provided.</span>
5831cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'skip option with message'</span>, { <span class="hljs-attr">skip</span>: <span class="hljs-string">'this is skipped'</span> }, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5841cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This code is never executed.</span>
5851cb0ef41Sopenharmony_ci});
5861cb0ef41Sopenharmony_ci
5871cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'skip() method'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5881cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Make sure to return here as well if the test contains additional logic.</span>
5891cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">skip</span>();
5901cb0ef41Sopenharmony_ci});
5911cb0ef41Sopenharmony_ci
5921cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'skip() method with message'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
5931cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Make sure to return here as well if the test contains additional logic.</span>
5941cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">skip</span>(<span class="hljs-string">'this is skipped'</span>);
5951cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
5961cb0ef41Sopenharmony_ci</section><section><h3><code>describe</code>/<code>it</code> syntax<span><a class="mark" href="#describeit-syntax" id="describeit-syntax">#</a></span><a aria-hidden="true" class="legacy" id="test_describe_it_syntax"></a></h3>
5971cb0ef41Sopenharmony_ci<p>Running tests can also be done using <code>describe</code> to declare a suite
5981cb0ef41Sopenharmony_ciand <code>it</code> to declare a test.
5991cb0ef41Sopenharmony_ciA suite is used to organize and group related tests together.
6001cb0ef41Sopenharmony_ci<code>it</code> is a shorthand for <a href="#testname-options-fn"><code>test()</code></a>.</p>
6011cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">describe</span>(<span class="hljs-string">'A thing'</span>, <span class="hljs-function">() =></span> {
6021cb0ef41Sopenharmony_ci  <span class="hljs-title function_">it</span>(<span class="hljs-string">'should work'</span>, <span class="hljs-function">() =></span> {
6031cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">1</span>, <span class="hljs-number">1</span>);
6041cb0ef41Sopenharmony_ci  });
6051cb0ef41Sopenharmony_ci
6061cb0ef41Sopenharmony_ci  <span class="hljs-title function_">it</span>(<span class="hljs-string">'should be ok'</span>, <span class="hljs-function">() =></span> {
6071cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">2</span>, <span class="hljs-number">2</span>);
6081cb0ef41Sopenharmony_ci  });
6091cb0ef41Sopenharmony_ci
6101cb0ef41Sopenharmony_ci  <span class="hljs-title function_">describe</span>(<span class="hljs-string">'a nested thing'</span>, <span class="hljs-function">() =></span> {
6111cb0ef41Sopenharmony_ci    <span class="hljs-title function_">it</span>(<span class="hljs-string">'should work'</span>, <span class="hljs-function">() =></span> {
6121cb0ef41Sopenharmony_ci      assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-number">3</span>, <span class="hljs-number">3</span>);
6131cb0ef41Sopenharmony_ci    });
6141cb0ef41Sopenharmony_ci  });
6151cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
6161cb0ef41Sopenharmony_ci<p><code>describe</code> and <code>it</code> are imported from the <code>node:test</code> module.</p>
6171cb0ef41Sopenharmony_ci
6181cb0ef41Sopenharmony_ci<pre class="with-46-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> { describe, it } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;</code><code class="language-js cjs"><span class="hljs-keyword">const</span> { describe, it } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);</code><button class="copy-button">copy</button></pre>
6191cb0ef41Sopenharmony_ci</section><section><h3><code>only</code> tests<span><a class="mark" href="#only-tests" id="only-tests">#</a></span><a aria-hidden="true" class="legacy" id="test_only_tests"></a></h3>
6201cb0ef41Sopenharmony_ci<p>If Node.js is started with the <a href="cli.html#--test-only"><code>--test-only</code></a> command-line option, it is
6211cb0ef41Sopenharmony_cipossible to skip all top level tests except for a selected subset by passing
6221cb0ef41Sopenharmony_cithe <code>only</code> option to the tests that should be run. When a test with the <code>only</code>
6231cb0ef41Sopenharmony_cioption set is run, all subtests are also run. The test context's <code>runOnly()</code>
6241cb0ef41Sopenharmony_cimethod can be used to implement the same behavior at the subtest level.</p>
6251cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-comment">// Assume Node.js is run with the --test-only command-line option.</span>
6261cb0ef41Sopenharmony_ci<span class="hljs-comment">// The 'only' option is set, so this test is run.</span>
6271cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'this test is run'</span>, { <span class="hljs-attr">only</span>: <span class="hljs-literal">true</span> }, <span class="hljs-keyword">async</span> (t) => {
6281cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Within this test, all subtests are run by default.</span>
6291cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'running subtest'</span>);
6301cb0ef41Sopenharmony_ci
6311cb0ef41Sopenharmony_ci  <span class="hljs-comment">// The test context can be updated to run subtests with the 'only' option.</span>
6321cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">runOnly</span>(<span class="hljs-literal">true</span>);
6331cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'this subtest is now skipped'</span>);
6341cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'this subtest is run'</span>, { <span class="hljs-attr">only</span>: <span class="hljs-literal">true</span> });
6351cb0ef41Sopenharmony_ci
6361cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Switch the context back to execute all tests.</span>
6371cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">runOnly</span>(<span class="hljs-literal">false</span>);
6381cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'this subtest is now run'</span>);
6391cb0ef41Sopenharmony_ci
6401cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Explicitly do not run these tests.</span>
6411cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'skipped subtest 3'</span>, { <span class="hljs-attr">only</span>: <span class="hljs-literal">false</span> });
6421cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'skipped subtest 4'</span>, { <span class="hljs-attr">skip</span>: <span class="hljs-literal">true</span> });
6431cb0ef41Sopenharmony_ci});
6441cb0ef41Sopenharmony_ci
6451cb0ef41Sopenharmony_ci<span class="hljs-comment">// The 'only' option is not set, so this test is skipped.</span>
6461cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'this test is not run'</span>, <span class="hljs-function">() =></span> {
6471cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This code is not run.</span>
6481cb0ef41Sopenharmony_ci  <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'fail'</span>);
6491cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
6501cb0ef41Sopenharmony_ci</section><section><h3>Filtering tests by name<span><a class="mark" href="#filtering-tests-by-name" id="filtering-tests-by-name">#</a></span><a aria-hidden="true" class="legacy" id="test_filtering_tests_by_name"></a></h3>
6511cb0ef41Sopenharmony_ci<p>The <a href="cli.html#--test-name-pattern"><code>--test-name-pattern</code></a> command-line option can be used to only run tests
6521cb0ef41Sopenharmony_ciwhose name matches the provided pattern. Test name patterns are interpreted as
6531cb0ef41Sopenharmony_ciJavaScript regular expressions. The <code>--test-name-pattern</code> option can be
6541cb0ef41Sopenharmony_cispecified multiple times in order to run nested tests. For each test that is
6551cb0ef41Sopenharmony_ciexecuted, any corresponding test hooks, such as <code>beforeEach()</code>, are also
6561cb0ef41Sopenharmony_cirun.</p>
6571cb0ef41Sopenharmony_ci<p>Given the following test file, starting Node.js with the
6581cb0ef41Sopenharmony_ci<code>--test-name-pattern="test [1-3]"</code> option would cause the test runner to execute
6591cb0ef41Sopenharmony_ci<code>test 1</code>, <code>test 2</code>, and <code>test 3</code>. If <code>test 1</code> did not match the test name
6601cb0ef41Sopenharmony_cipattern, then its subtests would not execute, despite matching the pattern. The
6611cb0ef41Sopenharmony_cisame set of tests could also be executed by passing <code>--test-name-pattern</code>
6621cb0ef41Sopenharmony_cimultiple times (e.g. <code>--test-name-pattern="test 1"</code>,
6631cb0ef41Sopenharmony_ci<code>--test-name-pattern="test 2"</code>, etc.).</p>
6641cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'test 1'</span>, <span class="hljs-keyword">async</span> (t) => {
6651cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'test 2'</span>);
6661cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'test 3'</span>);
6671cb0ef41Sopenharmony_ci});
6681cb0ef41Sopenharmony_ci
6691cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'Test 4'</span>, <span class="hljs-keyword">async</span> (t) => {
6701cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'Test 5'</span>);
6711cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'test 6'</span>);
6721cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
6731cb0ef41Sopenharmony_ci<p>Test name patterns can also be specified using regular expression literals. This
6741cb0ef41Sopenharmony_ciallows regular expression flags to be used. In the previous example, starting
6751cb0ef41Sopenharmony_ciNode.js with <code>--test-name-pattern="/test [4-5]/i"</code> would match <code>Test 4</code> and
6761cb0ef41Sopenharmony_ci<code>Test 5</code> because the pattern is case-insensitive.</p>
6771cb0ef41Sopenharmony_ci<p>Test name patterns do not change the set of files that the test runner executes.</p>
6781cb0ef41Sopenharmony_ci</section><section><h3>Extraneous asynchronous activity<span><a class="mark" href="#extraneous-asynchronous-activity" id="extraneous-asynchronous-activity">#</a></span><a aria-hidden="true" class="legacy" id="test_extraneous_asynchronous_activity"></a></h3>
6791cb0ef41Sopenharmony_ci<p>Once a test function finishes executing, the results are reported as quickly
6801cb0ef41Sopenharmony_cias possible while maintaining the order of the tests. However, it is possible
6811cb0ef41Sopenharmony_cifor the test function to generate asynchronous activity that outlives the test
6821cb0ef41Sopenharmony_ciitself. The test runner handles this type of activity, but does not delay the
6831cb0ef41Sopenharmony_cireporting of test results in order to accommodate it.</p>
6841cb0ef41Sopenharmony_ci<p>In the following example, a test completes with two <code>setImmediate()</code>
6851cb0ef41Sopenharmony_cioperations still outstanding. The first <code>setImmediate()</code> attempts to create a
6861cb0ef41Sopenharmony_cinew subtest. Because the parent test has already finished and output its
6871cb0ef41Sopenharmony_ciresults, the new subtest is immediately marked as failed, and reported later
6881cb0ef41Sopenharmony_cito the <a href="test.html#class-testsstream" class="type">&#x3C;TestsStream></a>.</p>
6891cb0ef41Sopenharmony_ci<p>The second <code>setImmediate()</code> creates an <code>uncaughtException</code> event.
6901cb0ef41Sopenharmony_ci<code>uncaughtException</code> and <code>unhandledRejection</code> events originating from a completed
6911cb0ef41Sopenharmony_citest are marked as failed by the <code>test</code> module and reported as diagnostic
6921cb0ef41Sopenharmony_ciwarnings at the top level by the <a href="test.html#class-testsstream" class="type">&#x3C;TestsStream></a>.</p>
6931cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'a test that creates asynchronous activity'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
6941cb0ef41Sopenharmony_ci  <span class="hljs-title function_">setImmediate</span>(<span class="hljs-function">() =></span> {
6951cb0ef41Sopenharmony_ci    t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'subtest that is created too late'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
6961cb0ef41Sopenharmony_ci      <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'error1'</span>);
6971cb0ef41Sopenharmony_ci    });
6981cb0ef41Sopenharmony_ci  });
6991cb0ef41Sopenharmony_ci
7001cb0ef41Sopenharmony_ci  <span class="hljs-title function_">setImmediate</span>(<span class="hljs-function">() =></span> {
7011cb0ef41Sopenharmony_ci    <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'error2'</span>);
7021cb0ef41Sopenharmony_ci  });
7031cb0ef41Sopenharmony_ci
7041cb0ef41Sopenharmony_ci  <span class="hljs-comment">// The test finishes after this line.</span>
7051cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
7061cb0ef41Sopenharmony_ci</section><section><h3>Watch mode<span><a class="mark" href="#watch-mode" id="watch-mode">#</a></span><a aria-hidden="true" class="legacy" id="test_watch_mode"></a></h3>
7071cb0ef41Sopenharmony_ci<div class="api_metadata">
7081cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
7091cb0ef41Sopenharmony_ci</div>
7101cb0ef41Sopenharmony_ci<p></p><div class="api_stability api_stability_1"><a href="documentation.html#stability-index">Stability: 1</a> - Experimental</div><p></p>
7111cb0ef41Sopenharmony_ci<p>The Node.js test runner supports running in watch mode by passing the <code>--watch</code> flag:</p>
7121cb0ef41Sopenharmony_ci<pre><code class="language-bash">node --<span class="hljs-built_in">test</span> --watch</code> <button class="copy-button">copy</button></pre>
7131cb0ef41Sopenharmony_ci<p>In watch mode, the test runner will watch for changes to test files and
7141cb0ef41Sopenharmony_citheir dependencies. When a change is detected, the test runner will
7151cb0ef41Sopenharmony_cirerun the tests affected by the change.
7161cb0ef41Sopenharmony_ciThe test runner will continue to run until the process is terminated.</p>
7171cb0ef41Sopenharmony_ci</section><section><h3>Running tests from the command line<span><a class="mark" href="#running-tests-from-the-command-line" id="running-tests-from-the-command-line">#</a></span><a aria-hidden="true" class="legacy" id="test_running_tests_from_the_command_line"></a></h3>
7181cb0ef41Sopenharmony_ci<p>The Node.js test runner can be invoked from the command line by passing the
7191cb0ef41Sopenharmony_ci<a href="cli.html#--test"><code>--test</code></a> flag:</p>
7201cb0ef41Sopenharmony_ci<pre><code class="language-bash">node --<span class="hljs-built_in">test</span></code> <button class="copy-button">copy</button></pre>
7211cb0ef41Sopenharmony_ci<p>By default, Node.js will recursively search the current directory for
7221cb0ef41Sopenharmony_ciJavaScript source files matching a specific naming convention. Matching files
7231cb0ef41Sopenharmony_ciare executed as test files. More information on the expected test file naming
7241cb0ef41Sopenharmony_ciconvention and behavior can be found in the <a href="#test-runner-execution-model">test runner execution model</a>
7251cb0ef41Sopenharmony_cisection.</p>
7261cb0ef41Sopenharmony_ci<p>Alternatively, one or more paths can be provided as the final argument(s) to
7271cb0ef41Sopenharmony_cithe Node.js command, as shown below.</p>
7281cb0ef41Sopenharmony_ci<pre><code class="language-bash">node --<span class="hljs-built_in">test</span> test1.js test2.mjs custom_test_dir/</code> <button class="copy-button">copy</button></pre>
7291cb0ef41Sopenharmony_ci<p>In this example, the test runner will execute the files <code>test1.js</code> and
7301cb0ef41Sopenharmony_ci<code>test2.mjs</code>. The test runner will also recursively search the
7311cb0ef41Sopenharmony_ci<code>custom_test_dir/</code> directory for test files to execute.</p>
7321cb0ef41Sopenharmony_ci<h4>Test runner execution model<span><a class="mark" href="#test-runner-execution-model" id="test-runner-execution-model">#</a></span><a aria-hidden="true" class="legacy" id="test_test_runner_execution_model"></a></h4>
7331cb0ef41Sopenharmony_ci<p>When searching for test files to execute, the test runner behaves as follows:</p>
7341cb0ef41Sopenharmony_ci<ul>
7351cb0ef41Sopenharmony_ci<li>Any files explicitly provided by the user are executed.</li>
7361cb0ef41Sopenharmony_ci<li>If the user did not explicitly specify any paths, the current working
7371cb0ef41Sopenharmony_cidirectory is recursively searched for files as specified in the following
7381cb0ef41Sopenharmony_cisteps.</li>
7391cb0ef41Sopenharmony_ci<li><code>node_modules</code> directories are skipped unless explicitly provided by the
7401cb0ef41Sopenharmony_ciuser.</li>
7411cb0ef41Sopenharmony_ci<li>If a directory named <code>test</code> is encountered, the test runner will search it
7421cb0ef41Sopenharmony_cirecursively for all all <code>.js</code>, <code>.cjs</code>, and <code>.mjs</code> files. All of these files
7431cb0ef41Sopenharmony_ciare treated as test files, and do not need to match the specific naming
7441cb0ef41Sopenharmony_ciconvention detailed below. This is to accommodate projects that place all of
7451cb0ef41Sopenharmony_citheir tests in a single <code>test</code> directory.</li>
7461cb0ef41Sopenharmony_ci<li>In all other directories, <code>.js</code>, <code>.cjs</code>, and <code>.mjs</code> files matching the
7471cb0ef41Sopenharmony_cifollowing patterns are treated as test files:
7481cb0ef41Sopenharmony_ci<ul>
7491cb0ef41Sopenharmony_ci<li><code>^test$</code> - Files whose basename is the string <code>'test'</code>. Examples:
7501cb0ef41Sopenharmony_ci<code>test.js</code>, <code>test.cjs</code>, <code>test.mjs</code>.</li>
7511cb0ef41Sopenharmony_ci<li><code>^test-.+</code> - Files whose basename starts with the string <code>'test-'</code>
7521cb0ef41Sopenharmony_cifollowed by one or more characters. Examples: <code>test-example.js</code>,
7531cb0ef41Sopenharmony_ci<code>test-another-example.mjs</code>.</li>
7541cb0ef41Sopenharmony_ci<li><code>.+[\.\-\_]test$</code> - Files whose basename ends with <code>.test</code>, <code>-test</code>, or
7551cb0ef41Sopenharmony_ci<code>_test</code>, preceded by one or more characters. Examples: <code>example.test.js</code>,
7561cb0ef41Sopenharmony_ci<code>example-test.cjs</code>, <code>example_test.mjs</code>.</li>
7571cb0ef41Sopenharmony_ci<li>Other file types understood by Node.js such as <code>.node</code> and <code>.json</code> are not
7581cb0ef41Sopenharmony_ciautomatically executed by the test runner, but are supported if explicitly
7591cb0ef41Sopenharmony_ciprovided on the command line.</li>
7601cb0ef41Sopenharmony_ci</ul>
7611cb0ef41Sopenharmony_ci</li>
7621cb0ef41Sopenharmony_ci</ul>
7631cb0ef41Sopenharmony_ci<p>Each matching test file is executed in a separate child process. The maximum
7641cb0ef41Sopenharmony_cinumber of child processes running at any time is controlled by the
7651cb0ef41Sopenharmony_ci<a href="cli.html#--test-concurrency"><code>--test-concurrency</code></a> flag. If the child process finishes with an exit code
7661cb0ef41Sopenharmony_ciof 0, the test is considered passing. Otherwise, the test is considered to be a
7671cb0ef41Sopenharmony_cifailure. Test files must be executable by Node.js, but are not required to use
7681cb0ef41Sopenharmony_cithe <code>node:test</code> module internally.</p>
7691cb0ef41Sopenharmony_ci<p>Each test file is executed as if it was a regular script. That is, if the test
7701cb0ef41Sopenharmony_cifile itself uses <code>node:test</code> to define tests, all of those tests will be
7711cb0ef41Sopenharmony_ciexecuted within a single application thread, regardless of the value of the
7721cb0ef41Sopenharmony_ci<code>concurrency</code> option of <a href="#testname-options-fn"><code>test()</code></a>.</p>
7731cb0ef41Sopenharmony_ci</section><section><h3>Collecting code coverage<span><a class="mark" href="#collecting-code-coverage" id="collecting-code-coverage">#</a></span><a aria-hidden="true" class="legacy" id="test_collecting_code_coverage"></a></h3>
7741cb0ef41Sopenharmony_ci<p>When Node.js is started with the <a href="cli.html#--experimental-test-coverage"><code>--experimental-test-coverage</code></a>
7751cb0ef41Sopenharmony_cicommand-line flag, code coverage is collected and statistics are reported once
7761cb0ef41Sopenharmony_ciall tests have completed. If the <a href="cli.html#node_v8_coveragedir"><code>NODE_V8_COVERAGE</code></a> environment variable is
7771cb0ef41Sopenharmony_ciused to specify a code coverage directory, the generated V8 coverage files are
7781cb0ef41Sopenharmony_ciwritten to that directory. Node.js core modules and files within
7791cb0ef41Sopenharmony_ci<code>node_modules/</code> directories are not included in the coverage report. If
7801cb0ef41Sopenharmony_cicoverage is enabled, the coverage report is sent to any <a href="#test-reporters">test reporters</a> via
7811cb0ef41Sopenharmony_cithe <code>'test:coverage'</code> event.</p>
7821cb0ef41Sopenharmony_ci<p>Coverage can be disabled on a series of lines using the following
7831cb0ef41Sopenharmony_cicomment syntax:</p>
7841cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-comment">/* node:coverage disable */</span>
7851cb0ef41Sopenharmony_ci<span class="hljs-keyword">if</span> (anAlwaysFalseCondition) {
7861cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Code in this branch will never be executed, but the lines are ignored for</span>
7871cb0ef41Sopenharmony_ci  <span class="hljs-comment">// coverage purposes. All lines following the 'disable' comment are ignored</span>
7881cb0ef41Sopenharmony_ci  <span class="hljs-comment">// until a corresponding 'enable' comment is encountered.</span>
7891cb0ef41Sopenharmony_ci  <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'this is never executed'</span>);
7901cb0ef41Sopenharmony_ci}
7911cb0ef41Sopenharmony_ci<span class="hljs-comment">/* node:coverage enable */</span></code> <button class="copy-button">copy</button></pre>
7921cb0ef41Sopenharmony_ci<p>Coverage can also be disabled for a specified number of lines. After the
7931cb0ef41Sopenharmony_cispecified number of lines, coverage will be automatically reenabled. If the
7941cb0ef41Sopenharmony_cinumber of lines is not explicitly provided, a single line is ignored.</p>
7951cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-comment">/* node:coverage ignore next */</span>
7961cb0ef41Sopenharmony_ci<span class="hljs-keyword">if</span> (anAlwaysFalseCondition) { <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'this is never executed'</span>); }
7971cb0ef41Sopenharmony_ci
7981cb0ef41Sopenharmony_ci<span class="hljs-comment">/* node:coverage ignore next 3 */</span>
7991cb0ef41Sopenharmony_ci<span class="hljs-keyword">if</span> (anAlwaysFalseCondition) {
8001cb0ef41Sopenharmony_ci  <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'this is never executed'</span>);
8011cb0ef41Sopenharmony_ci}</code> <button class="copy-button">copy</button></pre>
8021cb0ef41Sopenharmony_ci<p>The test runner's code coverage functionality has the following limitations,
8031cb0ef41Sopenharmony_ciwhich will be addressed in a future Node.js release:</p>
8041cb0ef41Sopenharmony_ci<ul>
8051cb0ef41Sopenharmony_ci<li>Source maps are not supported.</li>
8061cb0ef41Sopenharmony_ci<li>Excluding specific files or directories from the coverage report is not
8071cb0ef41Sopenharmony_cisupported.</li>
8081cb0ef41Sopenharmony_ci</ul>
8091cb0ef41Sopenharmony_ci</section><section><h3>Mocking<span><a class="mark" href="#mocking" id="mocking">#</a></span><a aria-hidden="true" class="legacy" id="test_mocking"></a></h3>
8101cb0ef41Sopenharmony_ci<p>The <code>node:test</code> module supports mocking during testing via a top-level <code>mock</code>
8111cb0ef41Sopenharmony_ciobject. The following example creates a spy on a function that adds two numbers
8121cb0ef41Sopenharmony_citogether. The spy is then used to assert that the function was called as
8131cb0ef41Sopenharmony_ciexpected.</p>
8141cb0ef41Sopenharmony_ci
8151cb0ef41Sopenharmony_ci<pre class="with-39-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
8161cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { mock, test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
8171cb0ef41Sopenharmony_ci
8181cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'spies on a function'</span>, <span class="hljs-function">() =></span> {
8191cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> sum = mock.<span class="hljs-title function_">fn</span>(<span class="hljs-function">(<span class="hljs-params">a, b</span>) =></span> {
8201cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> a + b;
8211cb0ef41Sopenharmony_ci  });
8221cb0ef41Sopenharmony_ci
8231cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(sum.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">0</span>);
8241cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">sum</span>(<span class="hljs-number">3</span>, <span class="hljs-number">4</span>), <span class="hljs-number">7</span>);
8251cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(sum.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">1</span>);
8261cb0ef41Sopenharmony_ci
8271cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> call = sum.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>[<span class="hljs-number">0</span>];
8281cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(call.<span class="hljs-property">arguments</span>, [<span class="hljs-number">3</span>, <span class="hljs-number">4</span>]);
8291cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">result</span>, <span class="hljs-number">7</span>);
8301cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">error</span>, <span class="hljs-literal">undefined</span>);
8311cb0ef41Sopenharmony_ci
8321cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Reset the globally tracked mocks.</span>
8331cb0ef41Sopenharmony_ci  mock.<span class="hljs-title function_">reset</span>();
8341cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-meta">'use strict'</span>;
8351cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
8361cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { mock, test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
8371cb0ef41Sopenharmony_ci
8381cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'spies on a function'</span>, <span class="hljs-function">() =></span> {
8391cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> sum = mock.<span class="hljs-title function_">fn</span>(<span class="hljs-function">(<span class="hljs-params">a, b</span>) =></span> {
8401cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> a + b;
8411cb0ef41Sopenharmony_ci  });
8421cb0ef41Sopenharmony_ci
8431cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(sum.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">0</span>);
8441cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">sum</span>(<span class="hljs-number">3</span>, <span class="hljs-number">4</span>), <span class="hljs-number">7</span>);
8451cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(sum.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">1</span>);
8461cb0ef41Sopenharmony_ci
8471cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> call = sum.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>[<span class="hljs-number">0</span>];
8481cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(call.<span class="hljs-property">arguments</span>, [<span class="hljs-number">3</span>, <span class="hljs-number">4</span>]);
8491cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">result</span>, <span class="hljs-number">7</span>);
8501cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">error</span>, <span class="hljs-literal">undefined</span>);
8511cb0ef41Sopenharmony_ci
8521cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Reset the globally tracked mocks.</span>
8531cb0ef41Sopenharmony_ci  mock.<span class="hljs-title function_">reset</span>();
8541cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
8551cb0ef41Sopenharmony_ci<p>The same mocking functionality is also exposed on the <a href="#class-testcontext"><code>TestContext</code></a> object
8561cb0ef41Sopenharmony_ciof each test. The following example creates a spy on an object method using the
8571cb0ef41Sopenharmony_ciAPI exposed on the <code>TestContext</code>. The benefit of mocking via the test context is
8581cb0ef41Sopenharmony_cithat the test runner will automatically restore all mocked functionality once
8591cb0ef41Sopenharmony_cithe test finishes.</p>
8601cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'spies on an object method'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
8611cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> number = {
8621cb0ef41Sopenharmony_ci    <span class="hljs-attr">value</span>: <span class="hljs-number">5</span>,
8631cb0ef41Sopenharmony_ci    <span class="hljs-title function_">add</span>(<span class="hljs-params">a</span>) {
8641cb0ef41Sopenharmony_ci      <span class="hljs-keyword">return</span> <span class="hljs-variable language_">this</span>.<span class="hljs-property">value</span> + a;
8651cb0ef41Sopenharmony_ci    },
8661cb0ef41Sopenharmony_ci  };
8671cb0ef41Sopenharmony_ci
8681cb0ef41Sopenharmony_ci  t.<span class="hljs-property">mock</span>.<span class="hljs-title function_">method</span>(number, <span class="hljs-string">'add'</span>);
8691cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(number.<span class="hljs-property">add</span>.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">0</span>);
8701cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(number.<span class="hljs-title function_">add</span>(<span class="hljs-number">3</span>), <span class="hljs-number">8</span>);
8711cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(number.<span class="hljs-property">add</span>.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">1</span>);
8721cb0ef41Sopenharmony_ci
8731cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> call = number.<span class="hljs-property">add</span>.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>[<span class="hljs-number">0</span>];
8741cb0ef41Sopenharmony_ci
8751cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(call.<span class="hljs-property">arguments</span>, [<span class="hljs-number">3</span>]);
8761cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">result</span>, <span class="hljs-number">8</span>);
8771cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">target</span>, <span class="hljs-literal">undefined</span>);
8781cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">this</span>, number);
8791cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
8801cb0ef41Sopenharmony_ci<h4>Timers<span><a class="mark" href="#timers" id="timers">#</a></span><a aria-hidden="true" class="legacy" id="test_timers"></a></h4>
8811cb0ef41Sopenharmony_ci<p>Mocking timers is a technique commonly used in software testing to simulate and
8821cb0ef41Sopenharmony_cicontrol the behavior of timers, such as <code>setInterval</code> and <code>setTimeout</code>,
8831cb0ef41Sopenharmony_ciwithout actually waiting for the specified time intervals.</p>
8841cb0ef41Sopenharmony_ci<p>Refer to the <a href="#class-mocktimers"><code>MockTimers</code></a> class for a full list of methods and features.</p>
8851cb0ef41Sopenharmony_ci<p>This allows developers to write more reliable and
8861cb0ef41Sopenharmony_cipredictable tests for time-dependent functionality.</p>
8871cb0ef41Sopenharmony_ci<p>The example below shows how to mock <code>setTimeout</code>.
8881cb0ef41Sopenharmony_ciUsing <code>.enable(['setTimeout']);</code>
8891cb0ef41Sopenharmony_ciit will mock the <code>setTimeout</code> functions in the <a href="./timers.html">node:timers</a> and
8901cb0ef41Sopenharmony_ci<a href="./timers.html#timers-promises-api">node:timers/promises</a> modules,
8911cb0ef41Sopenharmony_cias well as from the Node.js global context.</p>
8921cb0ef41Sopenharmony_ci<p><strong>Note:</strong> Destructuring functions such as
8931cb0ef41Sopenharmony_ci<code>import { setTimeout } from 'node:timers'</code>
8941cb0ef41Sopenharmony_ciis currently not supported by this API.</p>
8951cb0ef41Sopenharmony_ci<pre><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
8961cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { mock, test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
8971cb0ef41Sopenharmony_ci
8981cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">() =></span> {
8991cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = mock.<span class="hljs-title function_">fn</span>();
9001cb0ef41Sopenharmony_ci
9011cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
9021cb0ef41Sopenharmony_ci  mock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
9031cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
9041cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
9051cb0ef41Sopenharmony_ci
9061cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
9071cb0ef41Sopenharmony_ci  mock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
9081cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
9091cb0ef41Sopenharmony_ci
9101cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Reset the globally tracked mocks.</span>
9111cb0ef41Sopenharmony_ci  mock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">reset</span>();
9121cb0ef41Sopenharmony_ci
9131cb0ef41Sopenharmony_ci  <span class="hljs-comment">// If you call reset mock instance, it will also reset timers instance</span>
9141cb0ef41Sopenharmony_ci  mock.<span class="hljs-title function_">reset</span>();
9151cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
9161cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
9171cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { mock, test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
9181cb0ef41Sopenharmony_ci
9191cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">() =></span> {
9201cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = mock.<span class="hljs-title function_">fn</span>();
9211cb0ef41Sopenharmony_ci
9221cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
9231cb0ef41Sopenharmony_ci  mock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
9241cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
9251cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
9261cb0ef41Sopenharmony_ci
9271cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
9281cb0ef41Sopenharmony_ci  mock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
9291cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
9301cb0ef41Sopenharmony_ci
9311cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Reset the globally tracked mocks.</span>
9321cb0ef41Sopenharmony_ci  mock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">reset</span>();
9331cb0ef41Sopenharmony_ci
9341cb0ef41Sopenharmony_ci  <span class="hljs-comment">// If you call reset mock instance, it'll also reset timers instance</span>
9351cb0ef41Sopenharmony_ci  mock.<span class="hljs-title function_">reset</span>();
9361cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
9371cb0ef41Sopenharmony_ci<p>The same mocking functionality is also exposed in the mock property on the <a href="#class-testcontext"><code>TestContext</code></a> object
9381cb0ef41Sopenharmony_ciof each test. The benefit of mocking via the test context is
9391cb0ef41Sopenharmony_cithat the test runner will automatically restore all mocked timers
9401cb0ef41Sopenharmony_cifunctionality once the test finishes.</p>
9411cb0ef41Sopenharmony_ci<pre><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
9421cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
9431cb0ef41Sopenharmony_ci
9441cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
9451cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
9461cb0ef41Sopenharmony_ci
9471cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
9481cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
9491cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
9501cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
9511cb0ef41Sopenharmony_ci
9521cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
9531cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
9541cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
9551cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
9561cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
9571cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
9581cb0ef41Sopenharmony_ci
9591cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
9601cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
9611cb0ef41Sopenharmony_ci
9621cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
9631cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
9641cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
9651cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
9661cb0ef41Sopenharmony_ci
9671cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
9681cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
9691cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
9701cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
9711cb0ef41Sopenharmony_ci</section><section><h3>Test reporters<span><a class="mark" href="#test-reporters" id="test-reporters">#</a></span><a aria-hidden="true" class="legacy" id="test_test_reporters"></a></h3>
9721cb0ef41Sopenharmony_ci<div class="api_metadata">
9731cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
9741cb0ef41Sopenharmony_ci<table>
9751cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
9761cb0ef41Sopenharmony_ci<tr><td>v18.17.0</td>
9771cb0ef41Sopenharmony_ci<td><p>Reporters are now exposed at <code>node:test/reporters</code>.</p></td></tr>
9781cb0ef41Sopenharmony_ci<tr><td>v18.15.0</td>
9791cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.15.0</span></p></td></tr>
9801cb0ef41Sopenharmony_ci</tbody></table>
9811cb0ef41Sopenharmony_ci</details>
9821cb0ef41Sopenharmony_ci</div>
9831cb0ef41Sopenharmony_ci<p>The <code>node:test</code> module supports passing <a href="cli.html#--test-reporter"><code>--test-reporter</code></a>
9841cb0ef41Sopenharmony_ciflags for the test runner to use a specific reporter.</p>
9851cb0ef41Sopenharmony_ci<p>The following built-reporters are supported:</p>
9861cb0ef41Sopenharmony_ci<ul>
9871cb0ef41Sopenharmony_ci<li>
9881cb0ef41Sopenharmony_ci<p><code>tap</code>
9891cb0ef41Sopenharmony_ciThe <code>tap</code> reporter outputs the test results in the <a href="https://testanything.org/">TAP</a> format.</p>
9901cb0ef41Sopenharmony_ci</li>
9911cb0ef41Sopenharmony_ci<li>
9921cb0ef41Sopenharmony_ci<p><code>spec</code>
9931cb0ef41Sopenharmony_ciThe <code>spec</code> reporter outputs the test results in a human-readable format.</p>
9941cb0ef41Sopenharmony_ci</li>
9951cb0ef41Sopenharmony_ci<li>
9961cb0ef41Sopenharmony_ci<p><code>dot</code>
9971cb0ef41Sopenharmony_ciThe <code>dot</code> reporter outputs the test results in a compact format,
9981cb0ef41Sopenharmony_ciwhere each passing test is represented by a <code>.</code>,
9991cb0ef41Sopenharmony_ciand each failing test is represented by a <code>X</code>.</p>
10001cb0ef41Sopenharmony_ci</li>
10011cb0ef41Sopenharmony_ci<li>
10021cb0ef41Sopenharmony_ci<p><code>junit</code>
10031cb0ef41Sopenharmony_ciThe junit reporter outputs test results in a jUnit XML format</p>
10041cb0ef41Sopenharmony_ci</li>
10051cb0ef41Sopenharmony_ci</ul>
10061cb0ef41Sopenharmony_ci<p>When <code>stdout</code> is a <a href="tty.html">TTY</a>, the <code>spec</code> reporter is used by default.
10071cb0ef41Sopenharmony_ciOtherwise, the <code>tap</code> reporter is used by default.</p>
10081cb0ef41Sopenharmony_ci<p>The reporters are available via the <code>node:test/reporters</code> module:</p>
10091cb0ef41Sopenharmony_ci
10101cb0ef41Sopenharmony_ci<pre class="with-65-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> { tap, spec, dot, junit } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test/reporters'</span>;</code><code class="language-js cjs"><span class="hljs-keyword">const</span> { tap, spec, dot, junit } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test/reporters'</span>);</code><button class="copy-button">copy</button></pre>
10111cb0ef41Sopenharmony_ci<h4>Custom reporters<span><a class="mark" href="#custom-reporters" id="custom-reporters">#</a></span><a aria-hidden="true" class="legacy" id="test_custom_reporters"></a></h4>
10121cb0ef41Sopenharmony_ci<p><a href="cli.html#--test-reporter"><code>--test-reporter</code></a> can be used to specify a path to custom reporter.
10131cb0ef41Sopenharmony_ciA custom reporter is a module that exports a value
10141cb0ef41Sopenharmony_ciaccepted by <a href="stream.html#streamcomposestreams">stream.compose</a>.
10151cb0ef41Sopenharmony_ciReporters should transform events emitted by a <a href="test.html#class-testsstream" class="type">&#x3C;TestsStream></a></p>
10161cb0ef41Sopenharmony_ci<p>Example of a custom reporter using <a href="stream.html#class-streamtransform" class="type">&#x3C;stream.Transform></a>:</p>
10171cb0ef41Sopenharmony_ci
10181cb0ef41Sopenharmony_ci<pre class="with-45-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> { <span class="hljs-title class_">Transform</span> } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:stream'</span>;
10191cb0ef41Sopenharmony_ci
10201cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> customReporter = <span class="hljs-keyword">new</span> <span class="hljs-title class_">Transform</span>({
10211cb0ef41Sopenharmony_ci  <span class="hljs-attr">writableObjectMode</span>: <span class="hljs-literal">true</span>,
10221cb0ef41Sopenharmony_ci  <span class="hljs-title function_">transform</span>(<span class="hljs-params">event, encoding, callback</span>) {
10231cb0ef41Sopenharmony_ci    <span class="hljs-keyword">switch</span> (event.<span class="hljs-property">type</span>) {
10241cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:dequeue'</span>:
10251cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> dequeued`</span>);
10261cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10271cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:enqueue'</span>:
10281cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> enqueued`</span>);
10291cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10301cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:watch:drained'</span>:
10311cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">'test watch queue drained'</span>);
10321cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10331cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:start'</span>:
10341cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> started`</span>);
10351cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10361cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:pass'</span>:
10371cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> passed`</span>);
10381cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10391cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:fail'</span>:
10401cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> failed`</span>);
10411cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10421cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:plan'</span>:
10431cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">'test plan'</span>);
10441cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10451cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:diagnostic'</span>:
10461cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stderr'</span>:
10471cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stdout'</span>:
10481cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, event.<span class="hljs-property">data</span>.<span class="hljs-property">message</span>);
10491cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10501cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:coverage'</span>: {
10511cb0ef41Sopenharmony_ci        <span class="hljs-keyword">const</span> { totalLineCount } = event.<span class="hljs-property">data</span>.<span class="hljs-property">summary</span>.<span class="hljs-property">totals</span>;
10521cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`total line count: <span class="hljs-subst">${totalLineCount}</span>\n`</span>);
10531cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10541cb0ef41Sopenharmony_ci      }
10551cb0ef41Sopenharmony_ci    }
10561cb0ef41Sopenharmony_ci  },
10571cb0ef41Sopenharmony_ci});
10581cb0ef41Sopenharmony_ci
10591cb0ef41Sopenharmony_ci<span class="hljs-keyword">export</span> <span class="hljs-keyword">default</span> customReporter;</code><code class="language-js cjs"><span class="hljs-keyword">const</span> { <span class="hljs-title class_">Transform</span> } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:stream'</span>);
10601cb0ef41Sopenharmony_ci
10611cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> customReporter = <span class="hljs-keyword">new</span> <span class="hljs-title class_">Transform</span>({
10621cb0ef41Sopenharmony_ci  <span class="hljs-attr">writableObjectMode</span>: <span class="hljs-literal">true</span>,
10631cb0ef41Sopenharmony_ci  <span class="hljs-title function_">transform</span>(<span class="hljs-params">event, encoding, callback</span>) {
10641cb0ef41Sopenharmony_ci    <span class="hljs-keyword">switch</span> (event.<span class="hljs-property">type</span>) {
10651cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:dequeue'</span>:
10661cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> dequeued`</span>);
10671cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10681cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:enqueue'</span>:
10691cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> enqueued`</span>);
10701cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10711cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:watch:drained'</span>:
10721cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">'test watch queue drained'</span>);
10731cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10741cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:start'</span>:
10751cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> started`</span>);
10761cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10771cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:pass'</span>:
10781cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> passed`</span>);
10791cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10801cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:fail'</span>:
10811cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> failed`</span>);
10821cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10831cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:plan'</span>:
10841cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">'test plan'</span>);
10851cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10861cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:diagnostic'</span>:
10871cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stderr'</span>:
10881cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stdout'</span>:
10891cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, event.<span class="hljs-property">data</span>.<span class="hljs-property">message</span>);
10901cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10911cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:coverage'</span>: {
10921cb0ef41Sopenharmony_ci        <span class="hljs-keyword">const</span> { totalLineCount } = event.<span class="hljs-property">data</span>.<span class="hljs-property">summary</span>.<span class="hljs-property">totals</span>;
10931cb0ef41Sopenharmony_ci        <span class="hljs-title function_">callback</span>(<span class="hljs-literal">null</span>, <span class="hljs-string">`total line count: <span class="hljs-subst">${totalLineCount}</span>\n`</span>);
10941cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
10951cb0ef41Sopenharmony_ci      }
10961cb0ef41Sopenharmony_ci    }
10971cb0ef41Sopenharmony_ci  },
10981cb0ef41Sopenharmony_ci});
10991cb0ef41Sopenharmony_ci
11001cb0ef41Sopenharmony_ci<span class="hljs-variable language_">module</span>.<span class="hljs-property">exports</span> = customReporter;</code><button class="copy-button">copy</button></pre>
11011cb0ef41Sopenharmony_ci<p>Example of a custom reporter using a generator function:</p>
11021cb0ef41Sopenharmony_ci
11031cb0ef41Sopenharmony_ci<pre class="with-58-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">export</span> <span class="hljs-keyword">default</span> <span class="hljs-keyword">async</span> <span class="hljs-keyword">function</span> * <span class="hljs-title function_">customReporter</span>(<span class="hljs-params">source</span>) {
11041cb0ef41Sopenharmony_ci  <span class="hljs-keyword">for</span> <span class="hljs-keyword">await</span> (<span class="hljs-keyword">const</span> event <span class="hljs-keyword">of</span> source) {
11051cb0ef41Sopenharmony_ci    <span class="hljs-keyword">switch</span> (event.<span class="hljs-property">type</span>) {
11061cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:dequeue'</span>:
11071cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> dequeued`</span>;
11081cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11091cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:enqueue'</span>:
11101cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> enqueued`</span>;
11111cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11121cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:watch:drained'</span>:
11131cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">'test watch queue drained'</span>;
11141cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11151cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:start'</span>:
11161cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> started\n`</span>;
11171cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11181cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:pass'</span>:
11191cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> passed\n`</span>;
11201cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11211cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:fail'</span>:
11221cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> failed\n`</span>;
11231cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11241cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:plan'</span>:
11251cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">'test plan'</span>;
11261cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11271cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:diagnostic'</span>:
11281cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stderr'</span>:
11291cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stdout'</span>:
11301cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`<span class="hljs-subst">${event.data.message}</span>\n`</span>;
11311cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11321cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:coverage'</span>: {
11331cb0ef41Sopenharmony_ci        <span class="hljs-keyword">const</span> { totalLineCount } = event.<span class="hljs-property">data</span>.<span class="hljs-property">summary</span>.<span class="hljs-property">totals</span>;
11341cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`total line count: <span class="hljs-subst">${totalLineCount}</span>\n`</span>;
11351cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11361cb0ef41Sopenharmony_ci      }
11371cb0ef41Sopenharmony_ci    }
11381cb0ef41Sopenharmony_ci  }
11391cb0ef41Sopenharmony_ci}</code><code class="language-js cjs"><span class="hljs-variable language_">module</span>.<span class="hljs-property">exports</span> = <span class="hljs-keyword">async</span> <span class="hljs-keyword">function</span> * <span class="hljs-title function_">customReporter</span>(<span class="hljs-params">source</span>) {
11401cb0ef41Sopenharmony_ci  <span class="hljs-keyword">for</span> <span class="hljs-keyword">await</span> (<span class="hljs-keyword">const</span> event <span class="hljs-keyword">of</span> source) {
11411cb0ef41Sopenharmony_ci    <span class="hljs-keyword">switch</span> (event.<span class="hljs-property">type</span>) {
11421cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:dequeue'</span>:
11431cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> dequeued`</span>;
11441cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11451cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:enqueue'</span>:
11461cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> enqueued`</span>;
11471cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11481cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:watch:drained'</span>:
11491cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">'test watch queue drained'</span>;
11501cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11511cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:start'</span>:
11521cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> started\n`</span>;
11531cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11541cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:pass'</span>:
11551cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> passed\n`</span>;
11561cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11571cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:fail'</span>:
11581cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`test <span class="hljs-subst">${event.data.name}</span> failed\n`</span>;
11591cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11601cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:plan'</span>:
11611cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">'test plan\n'</span>;
11621cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11631cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:diagnostic'</span>:
11641cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stderr'</span>:
11651cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:stdout'</span>:
11661cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`<span class="hljs-subst">${event.data.message}</span>\n`</span>;
11671cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11681cb0ef41Sopenharmony_ci      <span class="hljs-keyword">case</span> <span class="hljs-string">'test:coverage'</span>: {
11691cb0ef41Sopenharmony_ci        <span class="hljs-keyword">const</span> { totalLineCount } = event.<span class="hljs-property">data</span>.<span class="hljs-property">summary</span>.<span class="hljs-property">totals</span>;
11701cb0ef41Sopenharmony_ci        <span class="hljs-keyword">yield</span> <span class="hljs-string">`total line count: <span class="hljs-subst">${totalLineCount}</span>\n`</span>;
11711cb0ef41Sopenharmony_ci        <span class="hljs-keyword">break</span>;
11721cb0ef41Sopenharmony_ci      }
11731cb0ef41Sopenharmony_ci    }
11741cb0ef41Sopenharmony_ci  }
11751cb0ef41Sopenharmony_ci};</code><button class="copy-button">copy</button></pre>
11761cb0ef41Sopenharmony_ci<p>The value provided to <code>--test-reporter</code> should be a string like one used in an
11771cb0ef41Sopenharmony_ci<code>import()</code> in JavaScript code.</p>
11781cb0ef41Sopenharmony_ci<h4>Multiple reporters<span><a class="mark" href="#multiple-reporters" id="multiple-reporters">#</a></span><a aria-hidden="true" class="legacy" id="test_multiple_reporters"></a></h4>
11791cb0ef41Sopenharmony_ci<p>The <a href="cli.html#--test-reporter"><code>--test-reporter</code></a> flag can be specified multiple times to report test
11801cb0ef41Sopenharmony_ciresults in several formats. In this situation
11811cb0ef41Sopenharmony_ciit is required to specify a destination for each reporter
11821cb0ef41Sopenharmony_ciusing <a href="cli.html#--test-reporter-destination"><code>--test-reporter-destination</code></a>.
11831cb0ef41Sopenharmony_ciDestination can be <code>stdout</code>, <code>stderr</code>, or a file path.
11841cb0ef41Sopenharmony_ciReporters and destinations are paired according
11851cb0ef41Sopenharmony_cito the order they were specified.</p>
11861cb0ef41Sopenharmony_ci<p>In the following example, the <code>spec</code> reporter will output to <code>stdout</code>,
11871cb0ef41Sopenharmony_ciand the <code>dot</code> reporter will output to <code>file.txt</code>:</p>
11881cb0ef41Sopenharmony_ci<pre><code class="language-bash">node --test-reporter=spec --test-reporter=dot --test-reporter-destination=stdout --test-reporter-destination=file.txt</code> <button class="copy-button">copy</button></pre>
11891cb0ef41Sopenharmony_ci<p>When a single reporter is specified, the destination will default to <code>stdout</code>,
11901cb0ef41Sopenharmony_ciunless a destination is explicitly provided.</p>
11911cb0ef41Sopenharmony_ci</section><section><h3><code>run([options])</code><span><a class="mark" href="#runoptions" id="runoptions">#</a></span><a aria-hidden="true" class="legacy" id="test_run_options"></a></h3>
11921cb0ef41Sopenharmony_ci<div class="api_metadata">
11931cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
11941cb0ef41Sopenharmony_ci<table>
11951cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
11961cb0ef41Sopenharmony_ci<tr><td>v18.17.0</td>
11971cb0ef41Sopenharmony_ci<td><p>Add a testNamePatterns option.</p></td></tr>
11981cb0ef41Sopenharmony_ci<tr><td>v18.9.0</td>
11991cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.9.0</span></p></td></tr>
12001cb0ef41Sopenharmony_ci</tbody></table>
12011cb0ef41Sopenharmony_ci</details>
12021cb0ef41Sopenharmony_ci</div>
12031cb0ef41Sopenharmony_ci<ul>
12041cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for running tests. The following
12051cb0ef41Sopenharmony_ciproperties are supported:
12061cb0ef41Sopenharmony_ci<ul>
12071cb0ef41Sopenharmony_ci<li><code>concurrency</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If a number is provided,
12081cb0ef41Sopenharmony_cithen that many test processes would run in parallel, where each process
12091cb0ef41Sopenharmony_cicorresponds to one test file.
12101cb0ef41Sopenharmony_ciIf <code>true</code>, it would run <code>os.availableParallelism() - 1</code> test files in
12111cb0ef41Sopenharmony_ciparallel.
12121cb0ef41Sopenharmony_ciIf <code>false</code>, it would only run one test file at a time.
12131cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>false</code>.</li>
12141cb0ef41Sopenharmony_ci<li><code>files</code>: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a> An array containing the list of files to run.
12151cb0ef41Sopenharmony_ci<strong>Default</strong> matching files from <a href="#test-runner-execution-model">test runner execution model</a>.</li>
12161cb0ef41Sopenharmony_ci<li><code>inspectPort</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> Sets inspector port of test child process.
12171cb0ef41Sopenharmony_ciThis can be a number, or a function that takes no arguments and returns a
12181cb0ef41Sopenharmony_cinumber. If a nullish value is provided, each process gets its own port,
12191cb0ef41Sopenharmony_ciincremented from the primary's <code>process.debugPort</code>.
12201cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>undefined</code>.</li>
12211cb0ef41Sopenharmony_ci<li><code>only</code>: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If truthy, the test context will only run tests that
12221cb0ef41Sopenharmony_cihave the <code>only</code> option set</li>
12231cb0ef41Sopenharmony_ci<li><code>setup</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> A function that accepts the <code>TestsStream</code> instance
12241cb0ef41Sopenharmony_ciand can be used to setup listeners before any tests are run.
12251cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>undefined</code>.</li>
12261cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress test execution.</li>
12271cb0ef41Sopenharmony_ci<li><code>testNamePatterns</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp" class="type">&#x3C;RegExp></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a> A String, RegExp or a RegExp Array,
12281cb0ef41Sopenharmony_cithat can be used to only run tests whose name matches the provided pattern.
12291cb0ef41Sopenharmony_ciTest name patterns are interpreted as JavaScript regular expressions.
12301cb0ef41Sopenharmony_ciFor each test that is executed, any corresponding test hooks, such as
12311cb0ef41Sopenharmony_ci<code>beforeEach()</code>, are also run.
12321cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>undefined</code>.</li>
12331cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the test execution will
12341cb0ef41Sopenharmony_cifail after.
12351cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
12361cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
12371cb0ef41Sopenharmony_ci<li><code>watch</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> Whether to run in watch mode or not. <strong>Default:</strong> <code>false</code>.</li>
12381cb0ef41Sopenharmony_ci<li><code>shard</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Running tests in a specific shard. <strong>Default:</strong> <code>undefined</code>.
12391cb0ef41Sopenharmony_ci<ul>
12401cb0ef41Sopenharmony_ci<li><code>index</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> is a positive integer between 1 and <code>&#x3C;total></code>
12411cb0ef41Sopenharmony_cithat specifies the index of the shard to run. This option is <em>required</em>.</li>
12421cb0ef41Sopenharmony_ci<li><code>total</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> is a positive integer that specifies the total number
12431cb0ef41Sopenharmony_ciof shards to split the test files to. This option is <em>required</em>.</li>
12441cb0ef41Sopenharmony_ci</ul>
12451cb0ef41Sopenharmony_ci</li>
12461cb0ef41Sopenharmony_ci</ul>
12471cb0ef41Sopenharmony_ci</li>
12481cb0ef41Sopenharmony_ci<li>Returns: <a href="test.html#class-testsstream" class="type">&#x3C;TestsStream></a></li>
12491cb0ef41Sopenharmony_ci</ul>
12501cb0ef41Sopenharmony_ci
12511cb0ef41Sopenharmony_ci<pre class="with-47-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> { tap } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test/reporters'</span>;
12521cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> process <span class="hljs-keyword">from</span> <span class="hljs-string">'node:process'</span>;
12531cb0ef41Sopenharmony_ci
12541cb0ef41Sopenharmony_ci<span class="hljs-title function_">run</span>({ <span class="hljs-attr">files</span>: [path.<span class="hljs-title function_">resolve</span>(<span class="hljs-string">'./tests/test.js'</span>)] })
12551cb0ef41Sopenharmony_ci  .<span class="hljs-title function_">compose</span>(tap)
12561cb0ef41Sopenharmony_ci  .<span class="hljs-title function_">pipe</span>(process.<span class="hljs-property">stdout</span>);</code><code class="language-js cjs"><span class="hljs-keyword">const</span> { tap } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test/reporters'</span>);
12571cb0ef41Sopenharmony_ci
12581cb0ef41Sopenharmony_ci<span class="hljs-title function_">run</span>({ <span class="hljs-attr">files</span>: [path.<span class="hljs-title function_">resolve</span>(<span class="hljs-string">'./tests/test.js'</span>)] })
12591cb0ef41Sopenharmony_ci  .<span class="hljs-title function_">compose</span>(tap)
12601cb0ef41Sopenharmony_ci  .<span class="hljs-title function_">pipe</span>(process.<span class="hljs-property">stdout</span>);</code><button class="copy-button">copy</button></pre>
12611cb0ef41Sopenharmony_ci</section><section><h3><code>test([name][, options][, fn])</code><span><a class="mark" href="#testname-options-fn" id="testname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_test_name_options_fn"></a></h3>
12621cb0ef41Sopenharmony_ci<div class="api_metadata">
12631cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
12641cb0ef41Sopenharmony_ci<table>
12651cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
12661cb0ef41Sopenharmony_ci<tr><td>v18.17.0</td>
12671cb0ef41Sopenharmony_ci<td><p>Added the <code>skip</code>, <code>todo</code>, and <code>only</code> shorthands.</p></td></tr>
12681cb0ef41Sopenharmony_ci<tr><td>v18.8.0</td>
12691cb0ef41Sopenharmony_ci<td><p>Add a <code>signal</code> option.</p></td></tr>
12701cb0ef41Sopenharmony_ci<tr><td>v18.7.0</td>
12711cb0ef41Sopenharmony_ci<td><p>Add a <code>timeout</code> option.</p></td></tr>
12721cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td>
12731cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.0.0</span></p></td></tr>
12741cb0ef41Sopenharmony_ci</tbody></table>
12751cb0ef41Sopenharmony_ci</details>
12761cb0ef41Sopenharmony_ci</div>
12771cb0ef41Sopenharmony_ci<ul>
12781cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The name of the test, which is displayed when reporting test
12791cb0ef41Sopenharmony_ciresults. <strong>Default:</strong> The <code>name</code> property of <code>fn</code>, or <code>'&#x3C;anonymous>'</code> if <code>fn</code>
12801cb0ef41Sopenharmony_cidoes not have a name.</li>
12811cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the test. The following
12821cb0ef41Sopenharmony_ciproperties are supported:
12831cb0ef41Sopenharmony_ci<ul>
12841cb0ef41Sopenharmony_ci<li><code>concurrency</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If a number is provided,
12851cb0ef41Sopenharmony_cithen that many tests would run in parallel within the application thread.
12861cb0ef41Sopenharmony_ciIf <code>true</code>, all scheduled asynchronous tests run concurrently within the
12871cb0ef41Sopenharmony_cithread. If <code>false</code>, only one test runs at a time.
12881cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
12891cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>false</code>.</li>
12901cb0ef41Sopenharmony_ci<li><code>only</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If truthy, and the test context is configured to run
12911cb0ef41Sopenharmony_ci<code>only</code> tests, then this test will be run. Otherwise, the test is skipped.
12921cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>false</code>.</li>
12931cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress test.</li>
12941cb0ef41Sopenharmony_ci<li><code>skip</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> If truthy, the test is skipped. If a string is
12951cb0ef41Sopenharmony_ciprovided, that string is displayed in the test results as the reason for
12961cb0ef41Sopenharmony_ciskipping the test. <strong>Default:</strong> <code>false</code>.</li>
12971cb0ef41Sopenharmony_ci<li><code>todo</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> If truthy, the test marked as <code>TODO</code>. If a string
12981cb0ef41Sopenharmony_ciis provided, that string is displayed in the test results as the reason why
12991cb0ef41Sopenharmony_cithe test is <code>TODO</code>. <strong>Default:</strong> <code>false</code>.</li>
13001cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the test will fail after.
13011cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
13021cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
13031cb0ef41Sopenharmony_ci</ul>
13041cb0ef41Sopenharmony_ci</li>
13051cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The function under test. The first argument
13061cb0ef41Sopenharmony_cito this function is a <a href="#class-testcontext"><code>TestContext</code></a> object. If the test uses callbacks,
13071cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
13081cb0ef41Sopenharmony_cifunction.</li>
13091cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise" class="type">&#x3C;Promise></a> Resolved with <code>undefined</code> once
13101cb0ef41Sopenharmony_cithe test completes, or immediately if the test runs within <a href="#describename-options-fn"><code>describe()</code></a>.</li>
13111cb0ef41Sopenharmony_ci</ul>
13121cb0ef41Sopenharmony_ci<p>The <code>test()</code> function is the value imported from the <code>test</code> module. Each
13131cb0ef41Sopenharmony_ciinvocation of this function results in reporting the test to the <a href="test.html#class-testsstream" class="type">&#x3C;TestsStream></a>.</p>
13141cb0ef41Sopenharmony_ci<p>The <code>TestContext</code> object passed to the <code>fn</code> argument can be used to perform
13151cb0ef41Sopenharmony_ciactions related to the current test. Examples include skipping the test, adding
13161cb0ef41Sopenharmony_ciadditional diagnostic information, or creating subtests.</p>
13171cb0ef41Sopenharmony_ci<p><code>test()</code> returns a <code>Promise</code> that resolves once the test completes.
13181cb0ef41Sopenharmony_ciif <code>test()</code> is called within a <code>describe()</code> block, it resolve immediately.
13191cb0ef41Sopenharmony_ciThe return value can usually be discarded for top level tests.
13201cb0ef41Sopenharmony_ciHowever, the return value from subtests should be used to prevent the parent
13211cb0ef41Sopenharmony_citest from finishing first and cancelling the subtest
13221cb0ef41Sopenharmony_cias shown in the following example.</p>
13231cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
13241cb0ef41Sopenharmony_ci  <span class="hljs-comment">// The setTimeout() in the following subtest would cause it to outlive its</span>
13251cb0ef41Sopenharmony_ci  <span class="hljs-comment">// parent test if 'await' is removed on the next line. Once the parent test</span>
13261cb0ef41Sopenharmony_ci  <span class="hljs-comment">// completes, it will cancel any outstanding subtests.</span>
13271cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'longer running subtest'</span>, <span class="hljs-keyword">async</span> (t) => {
13281cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">Promise</span>(<span class="hljs-function">(<span class="hljs-params">resolve, reject</span>) =></span> {
13291cb0ef41Sopenharmony_ci      <span class="hljs-built_in">setTimeout</span>(resolve, <span class="hljs-number">1000</span>);
13301cb0ef41Sopenharmony_ci    });
13311cb0ef41Sopenharmony_ci  });
13321cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
13331cb0ef41Sopenharmony_ci<p>The <code>timeout</code> option can be used to fail the test if it takes longer than
13341cb0ef41Sopenharmony_ci<code>timeout</code> milliseconds to complete. However, it is not a reliable mechanism for
13351cb0ef41Sopenharmony_cicanceling tests because a running test might block the application thread and
13361cb0ef41Sopenharmony_cithus prevent the scheduled cancellation.</p>
13371cb0ef41Sopenharmony_ci</section><section><h3><code>test.skip([name][, options][, fn])</code><span><a class="mark" href="#testskipname-options-fn" id="testskipname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_test_skip_name_options_fn"></a></h3>
13381cb0ef41Sopenharmony_ci<p>Shorthand for skipping a test,
13391cb0ef41Sopenharmony_cisame as <a href="#testname-options-fn"><code>test([name], { skip: true }[, fn])</code></a>.</p>
13401cb0ef41Sopenharmony_ci</section><section><h3><code>test.todo([name][, options][, fn])</code><span><a class="mark" href="#testtodoname-options-fn" id="testtodoname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_test_todo_name_options_fn"></a></h3>
13411cb0ef41Sopenharmony_ci<p>Shorthand for marking a test as <code>TODO</code>,
13421cb0ef41Sopenharmony_cisame as <a href="#testname-options-fn"><code>test([name], { todo: true }[, fn])</code></a>.</p>
13431cb0ef41Sopenharmony_ci</section><section><h3><code>test.only([name][, options][, fn])</code><span><a class="mark" href="#testonlyname-options-fn" id="testonlyname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_test_only_name_options_fn"></a></h3>
13441cb0ef41Sopenharmony_ci<p>Shorthand for marking a test as <code>only</code>,
13451cb0ef41Sopenharmony_cisame as <a href="#testname-options-fn"><code>test([name], { only: true }[, fn])</code></a>.</p>
13461cb0ef41Sopenharmony_ci</section><section><h3><code>describe([name][, options][, fn])</code><span><a class="mark" href="#describename-options-fn" id="describename-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_describe_name_options_fn"></a></h3>
13471cb0ef41Sopenharmony_ci<ul>
13481cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The name of the suite, which is displayed when reporting test
13491cb0ef41Sopenharmony_ciresults. <strong>Default:</strong> The <code>name</code> property of <code>fn</code>, or <code>'&#x3C;anonymous>'</code> if <code>fn</code>
13501cb0ef41Sopenharmony_cidoes not have a name.</li>
13511cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the suite.
13521cb0ef41Sopenharmony_cisupports the same options as <code>test([name][, options][, fn])</code>.</li>
13531cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The function under suite
13541cb0ef41Sopenharmony_cideclaring all subtests and subsuites.
13551cb0ef41Sopenharmony_ciThe first argument to this function is a <a href="#class-suitecontext"><code>SuiteContext</code></a> object.
13561cb0ef41Sopenharmony_ci<strong>Default:</strong> A no-op function.</li>
13571cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise" class="type">&#x3C;Promise></a> Immediately fulfilled with <code>undefined</code>.</li>
13581cb0ef41Sopenharmony_ci</ul>
13591cb0ef41Sopenharmony_ci<p>The <code>describe()</code> function imported from the <code>node:test</code> module. Each
13601cb0ef41Sopenharmony_ciinvocation of this function results in the creation of a Subtest.
13611cb0ef41Sopenharmony_ciAfter invocation of top level <code>describe</code> functions,
13621cb0ef41Sopenharmony_ciall top level tests and suites will execute.</p>
13631cb0ef41Sopenharmony_ci</section><section><h3><code>describe.skip([name][, options][, fn])</code><span><a class="mark" href="#describeskipname-options-fn" id="describeskipname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_describe_skip_name_options_fn"></a></h3>
13641cb0ef41Sopenharmony_ci<p>Shorthand for skipping a suite, same as <a href="#describename-options-fn"><code>describe([name], { skip: true }[, fn])</code></a>.</p>
13651cb0ef41Sopenharmony_ci</section><section><h3><code>describe.todo([name][, options][, fn])</code><span><a class="mark" href="#describetodoname-options-fn" id="describetodoname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_describe_todo_name_options_fn"></a></h3>
13661cb0ef41Sopenharmony_ci<p>Shorthand for marking a suite as <code>TODO</code>, same as
13671cb0ef41Sopenharmony_ci<a href="#describename-options-fn"><code>describe([name], { todo: true }[, fn])</code></a>.</p>
13681cb0ef41Sopenharmony_ci</section><section><h3><code>describe.only([name][, options][, fn])</code><span><a class="mark" href="#describeonlyname-options-fn" id="describeonlyname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_describe_only_name_options_fn"></a></h3>
13691cb0ef41Sopenharmony_ci<div class="api_metadata">
13701cb0ef41Sopenharmony_ci<span>Added in: v18.15.0</span>
13711cb0ef41Sopenharmony_ci</div>
13721cb0ef41Sopenharmony_ci<p>Shorthand for marking a suite as <code>only</code>, same as
13731cb0ef41Sopenharmony_ci<a href="#describename-options-fn"><code>describe([name], { only: true }[, fn])</code></a>.</p>
13741cb0ef41Sopenharmony_ci</section><section><h3><code>it([name][, options][, fn])</code><span><a class="mark" href="#itname-options-fn" id="itname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_it_name_options_fn"></a></h3>
13751cb0ef41Sopenharmony_ci<div class="api_metadata">
13761cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
13771cb0ef41Sopenharmony_ci<table>
13781cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
13791cb0ef41Sopenharmony_ci<tr><td>v18.16.0</td>
13801cb0ef41Sopenharmony_ci<td><p>Calling <code>it()</code> is now equivalent to calling <code>test()</code>.</p></td></tr>
13811cb0ef41Sopenharmony_ci<tr><td>v18.6.0, v16.17.0</td>
13821cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.6.0, v16.17.0</span></p></td></tr>
13831cb0ef41Sopenharmony_ci</tbody></table>
13841cb0ef41Sopenharmony_ci</details>
13851cb0ef41Sopenharmony_ci</div>
13861cb0ef41Sopenharmony_ci<p>Shorthand for <a href="#testname-options-fn"><code>test()</code></a>.</p>
13871cb0ef41Sopenharmony_ci<p>The <code>it()</code> function is imported from the <code>node:test</code> module.</p>
13881cb0ef41Sopenharmony_ci</section><section><h3><code>it.skip([name][, options][, fn])</code><span><a class="mark" href="#itskipname-options-fn" id="itskipname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_it_skip_name_options_fn"></a></h3>
13891cb0ef41Sopenharmony_ci<p>Shorthand for skipping a test,
13901cb0ef41Sopenharmony_cisame as <a href="#testname-options-fn"><code>it([name], { skip: true }[, fn])</code></a>.</p>
13911cb0ef41Sopenharmony_ci</section><section><h3><code>it.todo([name][, options][, fn])</code><span><a class="mark" href="#ittodoname-options-fn" id="ittodoname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_it_todo_name_options_fn"></a></h3>
13921cb0ef41Sopenharmony_ci<p>Shorthand for marking a test as <code>TODO</code>,
13931cb0ef41Sopenharmony_cisame as <a href="#testname-options-fn"><code>it([name], { todo: true }[, fn])</code></a>.</p>
13941cb0ef41Sopenharmony_ci</section><section><h3><code>it.only([name][, options][, fn])</code><span><a class="mark" href="#itonlyname-options-fn" id="itonlyname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_it_only_name_options_fn"></a></h3>
13951cb0ef41Sopenharmony_ci<div class="api_metadata">
13961cb0ef41Sopenharmony_ci<span>Added in: v18.15.0</span>
13971cb0ef41Sopenharmony_ci</div>
13981cb0ef41Sopenharmony_ci<p>Shorthand for marking a test as <code>only</code>,
13991cb0ef41Sopenharmony_cisame as <a href="#testname-options-fn"><code>it([name], { only: true }[, fn])</code></a>.</p>
14001cb0ef41Sopenharmony_ci</section><section><h3><code>before([fn][, options])</code><span><a class="mark" href="#beforefn-options" id="beforefn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_before_fn_options"></a></h3>
14011cb0ef41Sopenharmony_ci<div class="api_metadata">
14021cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
14031cb0ef41Sopenharmony_ci</div>
14041cb0ef41Sopenharmony_ci<ul>
14051cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function.
14061cb0ef41Sopenharmony_ciIf the hook uses callbacks,
14071cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
14081cb0ef41Sopenharmony_cifunction.</li>
14091cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
14101cb0ef41Sopenharmony_ciproperties are supported:
14111cb0ef41Sopenharmony_ci<ul>
14121cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
14131cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
14141cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
14151cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
14161cb0ef41Sopenharmony_ci</ul>
14171cb0ef41Sopenharmony_ci</li>
14181cb0ef41Sopenharmony_ci</ul>
14191cb0ef41Sopenharmony_ci<p>This function is used to create a hook running before running a suite.</p>
14201cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">describe</span>(<span class="hljs-string">'tests'</span>, <span class="hljs-keyword">async</span> () => {
14211cb0ef41Sopenharmony_ci  <span class="hljs-title function_">before</span>(<span class="hljs-function">() =></span> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'about to run some test'</span>));
14221cb0ef41Sopenharmony_ci  <span class="hljs-title function_">it</span>(<span class="hljs-string">'is a subtest'</span>, <span class="hljs-function">() =></span> {
14231cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
14241cb0ef41Sopenharmony_ci  });
14251cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
14261cb0ef41Sopenharmony_ci</section><section><h3><code>after([fn][, options])</code><span><a class="mark" href="#afterfn-options" id="afterfn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_after_fn_options"></a></h3>
14271cb0ef41Sopenharmony_ci<div class="api_metadata">
14281cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
14291cb0ef41Sopenharmony_ci</div>
14301cb0ef41Sopenharmony_ci<ul>
14311cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function.
14321cb0ef41Sopenharmony_ciIf the hook uses callbacks,
14331cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
14341cb0ef41Sopenharmony_cifunction.</li>
14351cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
14361cb0ef41Sopenharmony_ciproperties are supported:
14371cb0ef41Sopenharmony_ci<ul>
14381cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
14391cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
14401cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
14411cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
14421cb0ef41Sopenharmony_ci</ul>
14431cb0ef41Sopenharmony_ci</li>
14441cb0ef41Sopenharmony_ci</ul>
14451cb0ef41Sopenharmony_ci<p>This function is used to create a hook running after  running a suite.</p>
14461cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">describe</span>(<span class="hljs-string">'tests'</span>, <span class="hljs-keyword">async</span> () => {
14471cb0ef41Sopenharmony_ci  <span class="hljs-title function_">after</span>(<span class="hljs-function">() =></span> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'finished running tests'</span>));
14481cb0ef41Sopenharmony_ci  <span class="hljs-title function_">it</span>(<span class="hljs-string">'is a subtest'</span>, <span class="hljs-function">() =></span> {
14491cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
14501cb0ef41Sopenharmony_ci  });
14511cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
14521cb0ef41Sopenharmony_ci</section><section><h3><code>beforeEach([fn][, options])</code><span><a class="mark" href="#beforeeachfn-options" id="beforeeachfn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_beforeeach_fn_options"></a></h3>
14531cb0ef41Sopenharmony_ci<div class="api_metadata">
14541cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
14551cb0ef41Sopenharmony_ci</div>
14561cb0ef41Sopenharmony_ci<ul>
14571cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function.
14581cb0ef41Sopenharmony_ciIf the hook uses callbacks,
14591cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
14601cb0ef41Sopenharmony_cifunction.</li>
14611cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
14621cb0ef41Sopenharmony_ciproperties are supported:
14631cb0ef41Sopenharmony_ci<ul>
14641cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
14651cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
14661cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
14671cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
14681cb0ef41Sopenharmony_ci</ul>
14691cb0ef41Sopenharmony_ci</li>
14701cb0ef41Sopenharmony_ci</ul>
14711cb0ef41Sopenharmony_ci<p>This function is used to create a hook running
14721cb0ef41Sopenharmony_cibefore each subtest of the current suite.</p>
14731cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">describe</span>(<span class="hljs-string">'tests'</span>, <span class="hljs-keyword">async</span> () => {
14741cb0ef41Sopenharmony_ci  <span class="hljs-title function_">beforeEach</span>(<span class="hljs-function">() =></span> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'about to run a test'</span>));
14751cb0ef41Sopenharmony_ci  <span class="hljs-title function_">it</span>(<span class="hljs-string">'is a subtest'</span>, <span class="hljs-function">() =></span> {
14761cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
14771cb0ef41Sopenharmony_ci  });
14781cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
14791cb0ef41Sopenharmony_ci</section><section><h3><code>afterEach([fn][, options])</code><span><a class="mark" href="#aftereachfn-options" id="aftereachfn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_aftereach_fn_options"></a></h3>
14801cb0ef41Sopenharmony_ci<div class="api_metadata">
14811cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
14821cb0ef41Sopenharmony_ci</div>
14831cb0ef41Sopenharmony_ci<ul>
14841cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function.
14851cb0ef41Sopenharmony_ciIf the hook uses callbacks,
14861cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
14871cb0ef41Sopenharmony_cifunction.</li>
14881cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
14891cb0ef41Sopenharmony_ciproperties are supported:
14901cb0ef41Sopenharmony_ci<ul>
14911cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
14921cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
14931cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
14941cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
14951cb0ef41Sopenharmony_ci</ul>
14961cb0ef41Sopenharmony_ci</li>
14971cb0ef41Sopenharmony_ci</ul>
14981cb0ef41Sopenharmony_ci<p>This function is used to create a hook running
14991cb0ef41Sopenharmony_ciafter each subtest of the current test.</p>
15001cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">describe</span>(<span class="hljs-string">'tests'</span>, <span class="hljs-keyword">async</span> () => {
15011cb0ef41Sopenharmony_ci  <span class="hljs-title function_">afterEach</span>(<span class="hljs-function">() =></span> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'finished running a test'</span>));
15021cb0ef41Sopenharmony_ci  <span class="hljs-title function_">it</span>(<span class="hljs-string">'is a subtest'</span>, <span class="hljs-function">() =></span> {
15031cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
15041cb0ef41Sopenharmony_ci  });
15051cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
15061cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>MockFunctionContext</code><span><a class="mark" href="#class-mockfunctioncontext" id="class-mockfunctioncontext">#</a></span><a aria-hidden="true" class="legacy" id="test_class_mockfunctioncontext"></a></h3>
15071cb0ef41Sopenharmony_ci<div class="api_metadata">
15081cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
15091cb0ef41Sopenharmony_ci</div>
15101cb0ef41Sopenharmony_ci<p>The <code>MockFunctionContext</code> class is used to inspect or manipulate the behavior of
15111cb0ef41Sopenharmony_cimocks created via the <a href="#class-mocktracker"><code>MockTracker</code></a> APIs.</p>
15121cb0ef41Sopenharmony_ci<h4><code>ctx.calls</code><span><a class="mark" href="#ctxcalls" id="ctxcalls">#</a></span><a aria-hidden="true" class="legacy" id="test_ctx_calls"></a></h4>
15131cb0ef41Sopenharmony_ci<div class="api_metadata">
15141cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
15151cb0ef41Sopenharmony_ci</div>
15161cb0ef41Sopenharmony_ci<ul>
15171cb0ef41Sopenharmony_ci<li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a></li>
15181cb0ef41Sopenharmony_ci</ul>
15191cb0ef41Sopenharmony_ci<p>A getter that returns a copy of the internal array used to track calls to the
15201cb0ef41Sopenharmony_cimock. Each entry in the array is an object with the following properties.</p>
15211cb0ef41Sopenharmony_ci<ul>
15221cb0ef41Sopenharmony_ci<li><code>arguments</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a> An array of the arguments passed to the mock function.</li>
15231cb0ef41Sopenharmony_ci<li><code>error</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a> If the mocked function threw then this property contains the
15241cb0ef41Sopenharmony_cithrown value. <strong>Default:</strong> <code>undefined</code>.</li>
15251cb0ef41Sopenharmony_ci<li><code>result</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a> The value returned by the mocked function.</li>
15261cb0ef41Sopenharmony_ci<li><code>stack</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type">&#x3C;Error></a> An <code>Error</code> object whose stack can be used to determine the
15271cb0ef41Sopenharmony_cicallsite of the mocked function invocation.</li>
15281cb0ef41Sopenharmony_ci<li><code>target</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> If the mocked function is a constructor, this
15291cb0ef41Sopenharmony_cifield contains the class being constructed. Otherwise this will be
15301cb0ef41Sopenharmony_ci<code>undefined</code>.</li>
15311cb0ef41Sopenharmony_ci<li><code>this</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a> The mocked function's <code>this</code> value.</li>
15321cb0ef41Sopenharmony_ci</ul>
15331cb0ef41Sopenharmony_ci<h4><code>ctx.callCount()</code><span><a class="mark" href="#ctxcallcount" id="ctxcallcount">#</a></span><a aria-hidden="true" class="legacy" id="test_ctx_callcount"></a></h4>
15341cb0ef41Sopenharmony_ci<div class="api_metadata">
15351cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
15361cb0ef41Sopenharmony_ci</div>
15371cb0ef41Sopenharmony_ci<ul>
15381cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;integer></a> The number of times that this mock has been invoked.</li>
15391cb0ef41Sopenharmony_ci</ul>
15401cb0ef41Sopenharmony_ci<p>This function returns the number of times that this mock has been invoked. This
15411cb0ef41Sopenharmony_cifunction is more efficient than checking <code>ctx.calls.length</code> because <code>ctx.calls</code>
15421cb0ef41Sopenharmony_ciis a getter that creates a copy of the internal call tracking array.</p>
15431cb0ef41Sopenharmony_ci<h4><code>ctx.mockImplementation(implementation)</code><span><a class="mark" href="#ctxmockimplementationimplementation" id="ctxmockimplementationimplementation">#</a></span><a aria-hidden="true" class="legacy" id="test_ctx_mockimplementation_implementation"></a></h4>
15441cb0ef41Sopenharmony_ci<div class="api_metadata">
15451cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
15461cb0ef41Sopenharmony_ci</div>
15471cb0ef41Sopenharmony_ci<ul>
15481cb0ef41Sopenharmony_ci<li><code>implementation</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The function to be used as the
15491cb0ef41Sopenharmony_cimock's new implementation.</li>
15501cb0ef41Sopenharmony_ci</ul>
15511cb0ef41Sopenharmony_ci<p>This function is used to change the behavior of an existing mock.</p>
15521cb0ef41Sopenharmony_ci<p>The following example creates a mock function using <code>t.mock.fn()</code>, calls the
15531cb0ef41Sopenharmony_cimock function, and then changes the mock implementation to a different function.</p>
15541cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'changes a mock behavior'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
15551cb0ef41Sopenharmony_ci  <span class="hljs-keyword">let</span> cnt = <span class="hljs-number">0</span>;
15561cb0ef41Sopenharmony_ci
15571cb0ef41Sopenharmony_ci  <span class="hljs-keyword">function</span> <span class="hljs-title function_">addOne</span>(<span class="hljs-params"></span>) {
15581cb0ef41Sopenharmony_ci    cnt++;
15591cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> cnt;
15601cb0ef41Sopenharmony_ci  }
15611cb0ef41Sopenharmony_ci
15621cb0ef41Sopenharmony_ci  <span class="hljs-keyword">function</span> <span class="hljs-title function_">addTwo</span>(<span class="hljs-params"></span>) {
15631cb0ef41Sopenharmony_ci    cnt += <span class="hljs-number">2</span>;
15641cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> cnt;
15651cb0ef41Sopenharmony_ci  }
15661cb0ef41Sopenharmony_ci
15671cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = t.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>(addOne);
15681cb0ef41Sopenharmony_ci
15691cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">1</span>);
15701cb0ef41Sopenharmony_ci  fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">mockImplementation</span>(addTwo);
15711cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">3</span>);
15721cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">5</span>);
15731cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
15741cb0ef41Sopenharmony_ci<h4><code>ctx.mockImplementationOnce(implementation[, onCall])</code><span><a class="mark" href="#ctxmockimplementationonceimplementation-oncall" id="ctxmockimplementationonceimplementation-oncall">#</a></span><a aria-hidden="true" class="legacy" id="test_ctx_mockimplementationonce_implementation_oncall"></a></h4>
15751cb0ef41Sopenharmony_ci<div class="api_metadata">
15761cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
15771cb0ef41Sopenharmony_ci</div>
15781cb0ef41Sopenharmony_ci<ul>
15791cb0ef41Sopenharmony_ci<li><code>implementation</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The function to be used as the
15801cb0ef41Sopenharmony_cimock's implementation for the invocation number specified by <code>onCall</code>.</li>
15811cb0ef41Sopenharmony_ci<li><code>onCall</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;integer></a> The invocation number that will use <code>implementation</code>. If
15821cb0ef41Sopenharmony_cithe specified invocation has already occurred then an exception is thrown.
15831cb0ef41Sopenharmony_ci<strong>Default:</strong> The number of the next invocation.</li>
15841cb0ef41Sopenharmony_ci</ul>
15851cb0ef41Sopenharmony_ci<p>This function is used to change the behavior of an existing mock for a single
15861cb0ef41Sopenharmony_ciinvocation. Once invocation <code>onCall</code> has occurred, the mock will revert to
15871cb0ef41Sopenharmony_ciwhatever behavior it would have used had <code>mockImplementationOnce()</code> not been
15881cb0ef41Sopenharmony_cicalled.</p>
15891cb0ef41Sopenharmony_ci<p>The following example creates a mock function using <code>t.mock.fn()</code>, calls the
15901cb0ef41Sopenharmony_cimock function, changes the mock implementation to a different function for the
15911cb0ef41Sopenharmony_cinext invocation, and then resumes its previous behavior.</p>
15921cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'changes a mock behavior once'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
15931cb0ef41Sopenharmony_ci  <span class="hljs-keyword">let</span> cnt = <span class="hljs-number">0</span>;
15941cb0ef41Sopenharmony_ci
15951cb0ef41Sopenharmony_ci  <span class="hljs-keyword">function</span> <span class="hljs-title function_">addOne</span>(<span class="hljs-params"></span>) {
15961cb0ef41Sopenharmony_ci    cnt++;
15971cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> cnt;
15981cb0ef41Sopenharmony_ci  }
15991cb0ef41Sopenharmony_ci
16001cb0ef41Sopenharmony_ci  <span class="hljs-keyword">function</span> <span class="hljs-title function_">addTwo</span>(<span class="hljs-params"></span>) {
16011cb0ef41Sopenharmony_ci    cnt += <span class="hljs-number">2</span>;
16021cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> cnt;
16031cb0ef41Sopenharmony_ci  }
16041cb0ef41Sopenharmony_ci
16051cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = t.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>(addOne);
16061cb0ef41Sopenharmony_ci
16071cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">1</span>);
16081cb0ef41Sopenharmony_ci  fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">mockImplementationOnce</span>(addTwo);
16091cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">3</span>);
16101cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">4</span>);
16111cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
16121cb0ef41Sopenharmony_ci<h4><code>ctx.resetCalls()</code><span><a class="mark" href="#ctxresetcalls" id="ctxresetcalls">#</a></span><a aria-hidden="true" class="legacy" id="test_ctx_resetcalls"></a></h4>
16131cb0ef41Sopenharmony_ci<div class="api_metadata">
16141cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
16151cb0ef41Sopenharmony_ci</div>
16161cb0ef41Sopenharmony_ci<p>Resets the call history of the mock function.</p>
16171cb0ef41Sopenharmony_ci<h4><code>ctx.restore()</code><span><a class="mark" href="#ctxrestore" id="ctxrestore">#</a></span><a aria-hidden="true" class="legacy" id="test_ctx_restore"></a></h4>
16181cb0ef41Sopenharmony_ci<div class="api_metadata">
16191cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
16201cb0ef41Sopenharmony_ci</div>
16211cb0ef41Sopenharmony_ci<p>Resets the implementation of the mock function to its original behavior. The
16221cb0ef41Sopenharmony_cimock can still be used after calling this function.</p>
16231cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>MockTracker</code><span><a class="mark" href="#class-mocktracker" id="class-mocktracker">#</a></span><a aria-hidden="true" class="legacy" id="test_class_mocktracker"></a></h3>
16241cb0ef41Sopenharmony_ci<div class="api_metadata">
16251cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
16261cb0ef41Sopenharmony_ci</div>
16271cb0ef41Sopenharmony_ci<p>The <code>MockTracker</code> class is used to manage mocking functionality. The test runner
16281cb0ef41Sopenharmony_cimodule provides a top level <code>mock</code> export which is a <code>MockTracker</code> instance.
16291cb0ef41Sopenharmony_ciEach test also provides its own <code>MockTracker</code> instance via the test context's
16301cb0ef41Sopenharmony_ci<code>mock</code> property.</p>
16311cb0ef41Sopenharmony_ci<h4><code>mock.fn([original[, implementation]][, options])</code><span><a class="mark" href="#mockfnoriginal-implementation-options" id="mockfnoriginal-implementation-options">#</a></span><a aria-hidden="true" class="legacy" id="test_mock_fn_original_implementation_options"></a></h4>
16321cb0ef41Sopenharmony_ci<div class="api_metadata">
16331cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
16341cb0ef41Sopenharmony_ci</div>
16351cb0ef41Sopenharmony_ci<ul>
16361cb0ef41Sopenharmony_ci<li><code>original</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> An optional function to create a mock on.
16371cb0ef41Sopenharmony_ci<strong>Default:</strong> A no-op function.</li>
16381cb0ef41Sopenharmony_ci<li><code>implementation</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> An optional function used as the
16391cb0ef41Sopenharmony_cimock implementation for <code>original</code>. This is useful for creating mocks that
16401cb0ef41Sopenharmony_ciexhibit one behavior for a specified number of calls and then restore the
16411cb0ef41Sopenharmony_cibehavior of <code>original</code>. <strong>Default:</strong> The function specified by <code>original</code>.</li>
16421cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Optional configuration options for the mock function. The
16431cb0ef41Sopenharmony_cifollowing properties are supported:
16441cb0ef41Sopenharmony_ci<ul>
16451cb0ef41Sopenharmony_ci<li><code>times</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;integer></a> The number of times that the mock will use the behavior of
16461cb0ef41Sopenharmony_ci<code>implementation</code>. Once the mock function has been called <code>times</code> times, it
16471cb0ef41Sopenharmony_ciwill automatically restore the behavior of <code>original</code>. This value must be an
16481cb0ef41Sopenharmony_ciinteger greater than zero. <strong>Default:</strong> <code>Infinity</code>.</li>
16491cb0ef41Sopenharmony_ci</ul>
16501cb0ef41Sopenharmony_ci</li>
16511cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy" class="type">&#x3C;Proxy></a> The mocked function. The mocked function contains a special
16521cb0ef41Sopenharmony_ci<code>mock</code> property, which is an instance of <a href="#class-mockfunctioncontext"><code>MockFunctionContext</code></a>, and can
16531cb0ef41Sopenharmony_cibe used for inspecting and changing the behavior of the mocked function.</li>
16541cb0ef41Sopenharmony_ci</ul>
16551cb0ef41Sopenharmony_ci<p>This function is used to create a mock function.</p>
16561cb0ef41Sopenharmony_ci<p>The following example creates a mock function that increments a counter by one
16571cb0ef41Sopenharmony_cion each invocation. The <code>times</code> option is used to modify the mock behavior such
16581cb0ef41Sopenharmony_cithat the first two invocations add two to the counter instead of one.</p>
16591cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks a counting function'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
16601cb0ef41Sopenharmony_ci  <span class="hljs-keyword">let</span> cnt = <span class="hljs-number">0</span>;
16611cb0ef41Sopenharmony_ci
16621cb0ef41Sopenharmony_ci  <span class="hljs-keyword">function</span> <span class="hljs-title function_">addOne</span>(<span class="hljs-params"></span>) {
16631cb0ef41Sopenharmony_ci    cnt++;
16641cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> cnt;
16651cb0ef41Sopenharmony_ci  }
16661cb0ef41Sopenharmony_ci
16671cb0ef41Sopenharmony_ci  <span class="hljs-keyword">function</span> <span class="hljs-title function_">addTwo</span>(<span class="hljs-params"></span>) {
16681cb0ef41Sopenharmony_ci    cnt += <span class="hljs-number">2</span>;
16691cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> cnt;
16701cb0ef41Sopenharmony_ci  }
16711cb0ef41Sopenharmony_ci
16721cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = t.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>(addOne, addTwo, { <span class="hljs-attr">times</span>: <span class="hljs-number">2</span> });
16731cb0ef41Sopenharmony_ci
16741cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">2</span>);
16751cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">4</span>);
16761cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">5</span>);
16771cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(<span class="hljs-title function_">fn</span>(), <span class="hljs-number">6</span>);
16781cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
16791cb0ef41Sopenharmony_ci<h4><code>mock.getter(object, methodName[, implementation][, options])</code><span><a class="mark" href="#mockgetterobject-methodname-implementation-options" id="mockgetterobject-methodname-implementation-options">#</a></span><a aria-hidden="true" class="legacy" id="test_mock_getter_object_methodname_implementation_options"></a></h4>
16801cb0ef41Sopenharmony_ci<div class="api_metadata">
16811cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
16821cb0ef41Sopenharmony_ci</div>
16831cb0ef41Sopenharmony_ci<p>This function is syntax sugar for <a href="#mockmethodobject-methodname-implementation-options"><code>MockTracker.method</code></a> with <code>options.getter</code>
16841cb0ef41Sopenharmony_ciset to <code>true</code>.</p>
16851cb0ef41Sopenharmony_ci<h4><code>mock.method(object, methodName[, implementation][, options])</code><span><a class="mark" href="#mockmethodobject-methodname-implementation-options" id="mockmethodobject-methodname-implementation-options">#</a></span><a aria-hidden="true" class="legacy" id="test_mock_method_object_methodname_implementation_options"></a></h4>
16861cb0ef41Sopenharmony_ci<div class="api_metadata">
16871cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
16881cb0ef41Sopenharmony_ci</div>
16891cb0ef41Sopenharmony_ci<ul>
16901cb0ef41Sopenharmony_ci<li><code>object</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> The object whose method is being mocked.</li>
16911cb0ef41Sopenharmony_ci<li><code>methodName</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Symbol_type" class="type">&#x3C;symbol></a> The identifier of the method on <code>object</code> to mock.
16921cb0ef41Sopenharmony_ciIf <code>object[methodName]</code> is not a function, an error is thrown.</li>
16931cb0ef41Sopenharmony_ci<li><code>implementation</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> An optional function used as the
16941cb0ef41Sopenharmony_cimock implementation for <code>object[methodName]</code>. <strong>Default:</strong> The original method
16951cb0ef41Sopenharmony_cispecified by <code>object[methodName]</code>.</li>
16961cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Optional configuration options for the mock method. The
16971cb0ef41Sopenharmony_cifollowing properties are supported:
16981cb0ef41Sopenharmony_ci<ul>
16991cb0ef41Sopenharmony_ci<li><code>getter</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If <code>true</code>, <code>object[methodName]</code> is treated as a getter.
17001cb0ef41Sopenharmony_ciThis option cannot be used with the <code>setter</code> option. <strong>Default:</strong> false.</li>
17011cb0ef41Sopenharmony_ci<li><code>setter</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If <code>true</code>, <code>object[methodName]</code> is treated as a setter.
17021cb0ef41Sopenharmony_ciThis option cannot be used with the <code>getter</code> option. <strong>Default:</strong> false.</li>
17031cb0ef41Sopenharmony_ci<li><code>times</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;integer></a> The number of times that the mock will use the behavior of
17041cb0ef41Sopenharmony_ci<code>implementation</code>. Once the mocked method has been called <code>times</code> times, it
17051cb0ef41Sopenharmony_ciwill automatically restore the original behavior. This value must be an
17061cb0ef41Sopenharmony_ciinteger greater than zero. <strong>Default:</strong> <code>Infinity</code>.</li>
17071cb0ef41Sopenharmony_ci</ul>
17081cb0ef41Sopenharmony_ci</li>
17091cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy" class="type">&#x3C;Proxy></a> The mocked method. The mocked method contains a special
17101cb0ef41Sopenharmony_ci<code>mock</code> property, which is an instance of <a href="#class-mockfunctioncontext"><code>MockFunctionContext</code></a>, and can
17111cb0ef41Sopenharmony_cibe used for inspecting and changing the behavior of the mocked method.</li>
17121cb0ef41Sopenharmony_ci</ul>
17131cb0ef41Sopenharmony_ci<p>This function is used to create a mock on an existing object method. The
17141cb0ef41Sopenharmony_cifollowing example demonstrates how a mock is created on an existing object
17151cb0ef41Sopenharmony_cimethod.</p>
17161cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'spies on an object method'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
17171cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> number = {
17181cb0ef41Sopenharmony_ci    <span class="hljs-attr">value</span>: <span class="hljs-number">5</span>,
17191cb0ef41Sopenharmony_ci    <span class="hljs-title function_">subtract</span>(<span class="hljs-params">a</span>) {
17201cb0ef41Sopenharmony_ci      <span class="hljs-keyword">return</span> <span class="hljs-variable language_">this</span>.<span class="hljs-property">value</span> - a;
17211cb0ef41Sopenharmony_ci    },
17221cb0ef41Sopenharmony_ci  };
17231cb0ef41Sopenharmony_ci
17241cb0ef41Sopenharmony_ci  t.<span class="hljs-property">mock</span>.<span class="hljs-title function_">method</span>(number, <span class="hljs-string">'subtract'</span>);
17251cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(number.<span class="hljs-property">subtract</span>.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">0</span>);
17261cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(number.<span class="hljs-title function_">subtract</span>(<span class="hljs-number">3</span>), <span class="hljs-number">2</span>);
17271cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(number.<span class="hljs-property">subtract</span>.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>.<span class="hljs-property">length</span>, <span class="hljs-number">1</span>);
17281cb0ef41Sopenharmony_ci
17291cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> call = number.<span class="hljs-property">subtract</span>.<span class="hljs-property">mock</span>.<span class="hljs-property">calls</span>[<span class="hljs-number">0</span>];
17301cb0ef41Sopenharmony_ci
17311cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(call.<span class="hljs-property">arguments</span>, [<span class="hljs-number">3</span>]);
17321cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">result</span>, <span class="hljs-number">2</span>);
17331cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">error</span>, <span class="hljs-literal">undefined</span>);
17341cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">target</span>, <span class="hljs-literal">undefined</span>);
17351cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(call.<span class="hljs-property">this</span>, number);
17361cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
17371cb0ef41Sopenharmony_ci<h4><code>mock.reset()</code><span><a class="mark" href="#mockreset" id="mockreset">#</a></span><a aria-hidden="true" class="legacy" id="test_mock_reset"></a></h4>
17381cb0ef41Sopenharmony_ci<div class="api_metadata">
17391cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
17401cb0ef41Sopenharmony_ci</div>
17411cb0ef41Sopenharmony_ci<p>This function restores the default behavior of all mocks that were previously
17421cb0ef41Sopenharmony_cicreated by this <code>MockTracker</code> and disassociates the mocks from the
17431cb0ef41Sopenharmony_ci<code>MockTracker</code> instance. Once disassociated, the mocks can still be used, but the
17441cb0ef41Sopenharmony_ci<code>MockTracker</code> instance can no longer be used to reset their behavior or
17451cb0ef41Sopenharmony_ciotherwise interact with them.</p>
17461cb0ef41Sopenharmony_ci<p>After each test completes, this function is called on the test context's
17471cb0ef41Sopenharmony_ci<code>MockTracker</code>. If the global <code>MockTracker</code> is used extensively, calling this
17481cb0ef41Sopenharmony_cifunction manually is recommended.</p>
17491cb0ef41Sopenharmony_ci<h4><code>mock.restoreAll()</code><span><a class="mark" href="#mockrestoreall" id="mockrestoreall">#</a></span><a aria-hidden="true" class="legacy" id="test_mock_restoreall"></a></h4>
17501cb0ef41Sopenharmony_ci<div class="api_metadata">
17511cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
17521cb0ef41Sopenharmony_ci</div>
17531cb0ef41Sopenharmony_ci<p>This function restores the default behavior of all mocks that were previously
17541cb0ef41Sopenharmony_cicreated by this <code>MockTracker</code>. Unlike <code>mock.reset()</code>, <code>mock.restoreAll()</code> does
17551cb0ef41Sopenharmony_cinot disassociate the mocks from the <code>MockTracker</code> instance.</p>
17561cb0ef41Sopenharmony_ci<h4><code>mock.setter(object, methodName[, implementation][, options])</code><span><a class="mark" href="#mocksetterobject-methodname-implementation-options" id="mocksetterobject-methodname-implementation-options">#</a></span><a aria-hidden="true" class="legacy" id="test_mock_setter_object_methodname_implementation_options"></a></h4>
17571cb0ef41Sopenharmony_ci<div class="api_metadata">
17581cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
17591cb0ef41Sopenharmony_ci</div>
17601cb0ef41Sopenharmony_ci<p>This function is syntax sugar for <a href="#mockmethodobject-methodname-implementation-options"><code>MockTracker.method</code></a> with <code>options.setter</code>
17611cb0ef41Sopenharmony_ciset to <code>true</code>.</p>
17621cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>MockTimers</code><span><a class="mark" href="#class-mocktimers" id="class-mocktimers">#</a></span><a aria-hidden="true" class="legacy" id="test_class_mocktimers"></a></h3>
17631cb0ef41Sopenharmony_ci<div class="api_metadata">
17641cb0ef41Sopenharmony_ci<span>Added in: v18.19.0</span>
17651cb0ef41Sopenharmony_ci</div>
17661cb0ef41Sopenharmony_ci<p></p><div class="api_stability api_stability_1"><a href="documentation.html#stability-index">Stability: 1</a> - Experimental</div><p></p>
17671cb0ef41Sopenharmony_ci<p>Mocking timers is a technique commonly used in software testing to simulate and
17681cb0ef41Sopenharmony_cicontrol the behavior of timers, such as <code>setInterval</code> and <code>setTimeout</code>,
17691cb0ef41Sopenharmony_ciwithout actually waiting for the specified time intervals.</p>
17701cb0ef41Sopenharmony_ci<p>The <a href="#class-mocktracker"><code>MockTracker</code></a> provides a top-level <code>timers</code> export
17711cb0ef41Sopenharmony_ciwhich is a <code>MockTimers</code> instance.</p>
17721cb0ef41Sopenharmony_ci<h4><code>timers.enable([timers])</code><span><a class="mark" href="#timersenabletimers" id="timersenabletimers">#</a></span><a aria-hidden="true" class="legacy" id="test_timers_enable_timers"></a></h4>
17731cb0ef41Sopenharmony_ci<div class="api_metadata">
17741cb0ef41Sopenharmony_ci<span>Added in: v18.19.0</span>
17751cb0ef41Sopenharmony_ci</div>
17761cb0ef41Sopenharmony_ci<p>Enables timer mocking for the specified timers.</p>
17771cb0ef41Sopenharmony_ci<ul>
17781cb0ef41Sopenharmony_ci<li><code>timers</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a> An optional array containing the timers to mock.
17791cb0ef41Sopenharmony_ciThe currently supported timer values are <code>'setInterval'</code>, <code>'setTimeout'</code>,
17801cb0ef41Sopenharmony_ciand <code>'setImmediate'</code>.  If no value is provided, all timers (<code>'setInterval'</code>,
17811cb0ef41Sopenharmony_ci<code>'clearInterval'</code>, <code>'setTimeout'</code>, <code>'clearTimeout'</code>, <code>'setImmediate'</code>,
17821cb0ef41Sopenharmony_ciand <code>'clearImmediate'</code>) will be mocked by default.</li>
17831cb0ef41Sopenharmony_ci</ul>
17841cb0ef41Sopenharmony_ci<p><strong>Note:</strong> When you enable mocking for a specific timer, its associated
17851cb0ef41Sopenharmony_ciclear function will also be implicitly mocked.</p>
17861cb0ef41Sopenharmony_ci<p>Example usage:</p>
17871cb0ef41Sopenharmony_ci
17881cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> { mock } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
17891cb0ef41Sopenharmony_cimock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setInterval'</span>]);</code><code class="language-js cjs"><span class="hljs-keyword">const</span> { mock } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
17901cb0ef41Sopenharmony_cimock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setInterval'</span>]);</code><button class="copy-button">copy</button></pre>
17911cb0ef41Sopenharmony_ci<p>The above example enables mocking for the <code>setInterval</code> timer and
17921cb0ef41Sopenharmony_ciimplicitly mocks the <code>clearInterval</code> function. Only the <code>setInterval</code>
17931cb0ef41Sopenharmony_ciand <code>clearInterval</code> functions from <a href="./timers.html">node:timers</a>,
17941cb0ef41Sopenharmony_ci<a href="./timers.html#timers-promises-api">node:timers/promises</a>, and
17951cb0ef41Sopenharmony_ci<code>globalThis</code> will be mocked.</p>
17961cb0ef41Sopenharmony_ci<p>Alternatively, if you call <code>mock.timers.enable()</code> without any parameters:</p>
17971cb0ef41Sopenharmony_ci<p>All timers (<code>'setInterval'</code>, <code>'clearInterval'</code>, <code>'setTimeout'</code>, and <code>'clearTimeout'</code>)
17981cb0ef41Sopenharmony_ciwill be mocked. The <code>setInterval</code>, <code>clearInterval</code>, <code>setTimeout</code>, and <code>clearTimeout</code>
17991cb0ef41Sopenharmony_cifunctions from <code>node:timers</code>, <code>node:timers/promises</code>,
18001cb0ef41Sopenharmony_ciand <code>globalThis</code> will be mocked.</p>
18011cb0ef41Sopenharmony_ci<h4><code>timers.reset()</code><span><a class="mark" href="#timersreset" id="timersreset">#</a></span><a aria-hidden="true" class="legacy" id="test_timers_reset"></a></h4>
18021cb0ef41Sopenharmony_ci<div class="api_metadata">
18031cb0ef41Sopenharmony_ci<span>Added in: v18.19.0</span>
18041cb0ef41Sopenharmony_ci</div>
18051cb0ef41Sopenharmony_ci<p>This function restores the default behavior of all mocks that were previously
18061cb0ef41Sopenharmony_cicreated by this  <code>MockTimers</code> instance and disassociates the mocks
18071cb0ef41Sopenharmony_cifrom the  <code>MockTracker</code> instance.</p>
18081cb0ef41Sopenharmony_ci<p><strong>Note:</strong> After each test completes, this function is called on
18091cb0ef41Sopenharmony_cithe test context's  <code>MockTracker</code>.</p>
18101cb0ef41Sopenharmony_ci
18111cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> { mock } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
18121cb0ef41Sopenharmony_cimock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">reset</span>();</code><code class="language-js cjs"><span class="hljs-keyword">const</span> { mock } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
18131cb0ef41Sopenharmony_cimock.<span class="hljs-property">timers</span>.<span class="hljs-title function_">reset</span>();</code><button class="copy-button">copy</button></pre>
18141cb0ef41Sopenharmony_ci<h4><code>timers[Symbol.dispose]()</code><span><a class="mark" href="#timerssymboldispose" id="timerssymboldispose">#</a></span><a aria-hidden="true" class="legacy" id="test_timers_symbol_dispose"></a></h4>
18151cb0ef41Sopenharmony_ci<p>Calls <code>timers.reset()</code>.</p>
18161cb0ef41Sopenharmony_ci<h4><code>timers.tick(milliseconds)</code><span><a class="mark" href="#timerstickmilliseconds" id="timerstickmilliseconds">#</a></span><a aria-hidden="true" class="legacy" id="test_timers_tick_milliseconds"></a></h4>
18171cb0ef41Sopenharmony_ci<div class="api_metadata">
18181cb0ef41Sopenharmony_ci<span>Added in: v18.19.0</span>
18191cb0ef41Sopenharmony_ci</div>
18201cb0ef41Sopenharmony_ci<p>Advances time for all mocked timers.</p>
18211cb0ef41Sopenharmony_ci<ul>
18221cb0ef41Sopenharmony_ci<li><code>milliseconds</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The amount of time, in milliseconds,
18231cb0ef41Sopenharmony_cito advance the timers.</li>
18241cb0ef41Sopenharmony_ci</ul>
18251cb0ef41Sopenharmony_ci<p><strong>Note:</strong> This diverges from how <code>setTimeout</code> in Node.js behaves and accepts
18261cb0ef41Sopenharmony_cionly positive numbers. In Node.js, <code>setTimeout</code> with negative numbers is
18271cb0ef41Sopenharmony_cionly supported for web compatibility reasons.</p>
18281cb0ef41Sopenharmony_ci<p>The following example mocks a <code>setTimeout</code> function and
18291cb0ef41Sopenharmony_ciby using <code>.tick</code> advances in
18301cb0ef41Sopenharmony_citime triggering all pending timers.</p>
18311cb0ef41Sopenharmony_ci
18321cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
18331cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
18341cb0ef41Sopenharmony_ci
18351cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
18361cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
18371cb0ef41Sopenharmony_ci
18381cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
18391cb0ef41Sopenharmony_ci
18401cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
18411cb0ef41Sopenharmony_ci
18421cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
18431cb0ef41Sopenharmony_ci
18441cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
18451cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
18461cb0ef41Sopenharmony_ci
18471cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
18481cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
18491cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
18501cb0ef41Sopenharmony_ci
18511cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
18521cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
18531cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
18541cb0ef41Sopenharmony_ci
18551cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
18561cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
18571cb0ef41Sopenharmony_ci
18581cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
18591cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
18601cb0ef41Sopenharmony_ci
18611cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
18621cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
18631cb0ef41Sopenharmony_ci<p>Alternativelly, the <code>.tick</code> function can be called many times</p>
18641cb0ef41Sopenharmony_ci
18651cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
18661cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
18671cb0ef41Sopenharmony_ci
18681cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
18691cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
18701cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
18711cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> nineSecs = <span class="hljs-number">9000</span>;
18721cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, nineSecs);
18731cb0ef41Sopenharmony_ci
18741cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> twoSeconds = <span class="hljs-number">3000</span>;
18751cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(twoSeconds);
18761cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(twoSeconds);
18771cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(twoSeconds);
18781cb0ef41Sopenharmony_ci
18791cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
18801cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
18811cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
18821cb0ef41Sopenharmony_ci
18831cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
18841cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
18851cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
18861cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> nineSecs = <span class="hljs-number">9000</span>;
18871cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(fn, nineSecs);
18881cb0ef41Sopenharmony_ci
18891cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> twoSeconds = <span class="hljs-number">3000</span>;
18901cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(twoSeconds);
18911cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(twoSeconds);
18921cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(twoSeconds);
18931cb0ef41Sopenharmony_ci
18941cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
18951cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
18961cb0ef41Sopenharmony_ci<h5>Using clear functions<span><a class="mark" href="#using-clear-functions" id="using-clear-functions">#</a></span><a aria-hidden="true" class="legacy" id="test_using_clear_functions"></a></h5>
18971cb0ef41Sopenharmony_ci<p>As mentioned, all clear functions from timers (<code>clearTimeout</code> and <code>clearInterval</code>)
18981cb0ef41Sopenharmony_ciare implicity mocked. Take a look at this example using <code>setTimeout</code>:</p>
18991cb0ef41Sopenharmony_ci
19001cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
19011cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
19021cb0ef41Sopenharmony_ci
19031cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
19041cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19051cb0ef41Sopenharmony_ci
19061cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
19071cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
19081cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> id = <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
19091cb0ef41Sopenharmony_ci
19101cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Implicity mocked as well</span>
19111cb0ef41Sopenharmony_ci  <span class="hljs-built_in">clearTimeout</span>(id);
19121cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
19131cb0ef41Sopenharmony_ci
19141cb0ef41Sopenharmony_ci  <span class="hljs-comment">// As that setTimeout was cleared the mock function will never be called</span>
19151cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
19161cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
19171cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
19181cb0ef41Sopenharmony_ci
19191cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
19201cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> fn = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19211cb0ef41Sopenharmony_ci
19221cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
19231cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
19241cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> id = <span class="hljs-built_in">setTimeout</span>(fn, <span class="hljs-number">9999</span>);
19251cb0ef41Sopenharmony_ci
19261cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Implicity mocked as well</span>
19271cb0ef41Sopenharmony_ci  <span class="hljs-built_in">clearTimeout</span>(id);
19281cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
19291cb0ef41Sopenharmony_ci
19301cb0ef41Sopenharmony_ci  <span class="hljs-comment">// As that setTimeout was cleared the mock function will never be called</span>
19311cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(fn.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">0</span>);
19321cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
19331cb0ef41Sopenharmony_ci<h5>Working with Node.js timers modules<span><a class="mark" href="#working-with-nodejs-timers-modules" id="working-with-nodejs-timers-modules">#</a></span><a aria-hidden="true" class="legacy" id="test_working_with_node_js_timers_modules"></a></h5>
19341cb0ef41Sopenharmony_ci<p>Once you enable mocking timers, <a href="./timers.html">node:timers</a>,
19351cb0ef41Sopenharmony_ci<a href="./timers.html#timers-promises-api">node:timers/promises</a> modules,
19361cb0ef41Sopenharmony_ciand timers from the Node.js global context are enabled:</p>
19371cb0ef41Sopenharmony_ci<p><strong>Note:</strong> Destructuring functions such as
19381cb0ef41Sopenharmony_ci<code>import { setTimeout } from 'node:timers'</code> is currently
19391cb0ef41Sopenharmony_cinot supported by this API.</p>
19401cb0ef41Sopenharmony_ci
19411cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
19421cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
19431cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> nodeTimers <span class="hljs-keyword">from</span> <span class="hljs-string">'node:timers'</span>;
19441cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> nodeTimersPromises <span class="hljs-keyword">from</span> <span class="hljs-string">'node:timers/promises'</span>;
19451cb0ef41Sopenharmony_ci
19461cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-keyword">async</span> (context) => {
19471cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> globalTimeoutObjectSpy = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19481cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> nodeTimerSpy = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19491cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> nodeTimerPromiseSpy = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19501cb0ef41Sopenharmony_ci
19511cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
19521cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
19531cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(globalTimeoutObjectSpy, <span class="hljs-number">9999</span>);
19541cb0ef41Sopenharmony_ci  nodeTimers.<span class="hljs-built_in">setTimeout</span>(nodeTimerSpy, <span class="hljs-number">9999</span>);
19551cb0ef41Sopenharmony_ci
19561cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> promise = nodeTimersPromises.<span class="hljs-built_in">setTimeout</span>(<span class="hljs-number">9999</span>).<span class="hljs-title function_">then</span>(nodeTimerPromiseSpy);
19571cb0ef41Sopenharmony_ci
19581cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
19591cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
19601cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(globalTimeoutObjectSpy.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
19611cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(nodeTimerSpy.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
19621cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> promise;
19631cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(nodeTimerPromiseSpy.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
19641cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
19651cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
19661cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> nodeTimers = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:timers'</span>);
19671cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> nodeTimersPromises = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:timers/promises'</span>);
19681cb0ef41Sopenharmony_ci
19691cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'mocks setTimeout to be executed synchronously without having to actually wait for it'</span>, <span class="hljs-keyword">async</span> (context) => {
19701cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> globalTimeoutObjectSpy = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19711cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> nodeTimerSpy = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19721cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> nodeTimerPromiseSpy = context.<span class="hljs-property">mock</span>.<span class="hljs-title function_">fn</span>();
19731cb0ef41Sopenharmony_ci
19741cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Optionally choose what to mock</span>
19751cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
19761cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(globalTimeoutObjectSpy, <span class="hljs-number">9999</span>);
19771cb0ef41Sopenharmony_ci  nodeTimers.<span class="hljs-built_in">setTimeout</span>(nodeTimerSpy, <span class="hljs-number">9999</span>);
19781cb0ef41Sopenharmony_ci
19791cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> promise = nodeTimersPromises.<span class="hljs-built_in">setTimeout</span>(<span class="hljs-number">9999</span>).<span class="hljs-title function_">then</span>(nodeTimerPromiseSpy);
19801cb0ef41Sopenharmony_ci
19811cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Advance in time</span>
19821cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(<span class="hljs-number">9999</span>);
19831cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(globalTimeoutObjectSpy.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
19841cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(nodeTimerSpy.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
19851cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> promise;
19861cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(nodeTimerPromiseSpy.<span class="hljs-property">mock</span>.<span class="hljs-title function_">callCount</span>(), <span class="hljs-number">1</span>);
19871cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
19881cb0ef41Sopenharmony_ci<p>In Node.js, <code>setInterval</code> from <a href="./timers.html#timers-promises-api">node:timers/promises</a>
19891cb0ef41Sopenharmony_ciis an <code>AsyncGenerator</code> and is also supported by this API:</p>
19901cb0ef41Sopenharmony_ci
19911cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
19921cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
19931cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> nodeTimersPromises <span class="hljs-keyword">from</span> <span class="hljs-string">'node:timers/promises'</span>;
19941cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'should tick five times testing a real use case'</span>, <span class="hljs-keyword">async</span> (context) => {
19951cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setInterval'</span>]);
19961cb0ef41Sopenharmony_ci
19971cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> expectedIterations = <span class="hljs-number">3</span>;
19981cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> interval = <span class="hljs-number">1000</span>;
19991cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> startedAt = <span class="hljs-title class_">Date</span>.<span class="hljs-title function_">now</span>();
20001cb0ef41Sopenharmony_ci  <span class="hljs-keyword">async</span> <span class="hljs-keyword">function</span> <span class="hljs-title function_">run</span>(<span class="hljs-params"></span>) {
20011cb0ef41Sopenharmony_ci    <span class="hljs-keyword">const</span> times = [];
20021cb0ef41Sopenharmony_ci    <span class="hljs-keyword">for</span> <span class="hljs-keyword">await</span> (<span class="hljs-keyword">const</span> time <span class="hljs-keyword">of</span> nodeTimersPromises.<span class="hljs-built_in">setInterval</span>(interval, startedAt)) {
20031cb0ef41Sopenharmony_ci      times.<span class="hljs-title function_">push</span>(time);
20041cb0ef41Sopenharmony_ci      <span class="hljs-keyword">if</span> (times.<span class="hljs-property">length</span> === expectedIterations) <span class="hljs-keyword">break</span>;
20051cb0ef41Sopenharmony_ci    }
20061cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> times;
20071cb0ef41Sopenharmony_ci  }
20081cb0ef41Sopenharmony_ci
20091cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> r = <span class="hljs-title function_">run</span>();
20101cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(interval);
20111cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(interval);
20121cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(interval);
20131cb0ef41Sopenharmony_ci
20141cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> timeResults = <span class="hljs-keyword">await</span> r;
20151cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(timeResults.<span class="hljs-property">length</span>, expectedIterations);
20161cb0ef41Sopenharmony_ci  <span class="hljs-keyword">for</span> (<span class="hljs-keyword">let</span> it = <span class="hljs-number">1</span>; it &#x3C; expectedIterations; it++) {
20171cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">strictEqual</span>(timeResults[it - <span class="hljs-number">1</span>], startedAt + (interval * it));
20181cb0ef41Sopenharmony_ci  }
20191cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
20201cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
20211cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> nodeTimersPromises = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:timers/promises'</span>);
20221cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'should tick five times testing a real use case'</span>, <span class="hljs-keyword">async</span> (context) => {
20231cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setInterval'</span>]);
20241cb0ef41Sopenharmony_ci
20251cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> expectedIterations = <span class="hljs-number">3</span>;
20261cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> interval = <span class="hljs-number">1000</span>;
20271cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> startedAt = <span class="hljs-title class_">Date</span>.<span class="hljs-title function_">now</span>();
20281cb0ef41Sopenharmony_ci  <span class="hljs-keyword">async</span> <span class="hljs-keyword">function</span> <span class="hljs-title function_">run</span>(<span class="hljs-params"></span>) {
20291cb0ef41Sopenharmony_ci    <span class="hljs-keyword">const</span> times = [];
20301cb0ef41Sopenharmony_ci    <span class="hljs-keyword">for</span> <span class="hljs-keyword">await</span> (<span class="hljs-keyword">const</span> time <span class="hljs-keyword">of</span> nodeTimersPromises.<span class="hljs-built_in">setInterval</span>(interval, startedAt)) {
20311cb0ef41Sopenharmony_ci      times.<span class="hljs-title function_">push</span>(time);
20321cb0ef41Sopenharmony_ci      <span class="hljs-keyword">if</span> (times.<span class="hljs-property">length</span> === expectedIterations) <span class="hljs-keyword">break</span>;
20331cb0ef41Sopenharmony_ci    }
20341cb0ef41Sopenharmony_ci    <span class="hljs-keyword">return</span> times;
20351cb0ef41Sopenharmony_ci  }
20361cb0ef41Sopenharmony_ci
20371cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> r = <span class="hljs-title function_">run</span>();
20381cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(interval);
20391cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(interval);
20401cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">tick</span>(interval);
20411cb0ef41Sopenharmony_ci
20421cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> timeResults = <span class="hljs-keyword">await</span> r;
20431cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">strictEqual</span>(timeResults.<span class="hljs-property">length</span>, expectedIterations);
20441cb0ef41Sopenharmony_ci  <span class="hljs-keyword">for</span> (<span class="hljs-keyword">let</span> it = <span class="hljs-number">1</span>; it &#x3C; expectedIterations; it++) {
20451cb0ef41Sopenharmony_ci    assert.<span class="hljs-title function_">strictEqual</span>(timeResults[it - <span class="hljs-number">1</span>], startedAt + (interval * it));
20461cb0ef41Sopenharmony_ci  }
20471cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
20481cb0ef41Sopenharmony_ci<h4><code>timers.runAll()</code><span><a class="mark" href="#timersrunall" id="timersrunall">#</a></span><a aria-hidden="true" class="legacy" id="test_timers_runall"></a></h4>
20491cb0ef41Sopenharmony_ci<div class="api_metadata">
20501cb0ef41Sopenharmony_ci<span>Added in: v18.19.0</span>
20511cb0ef41Sopenharmony_ci</div>
20521cb0ef41Sopenharmony_ci<p>Triggers all pending mocked timers immediately.</p>
20531cb0ef41Sopenharmony_ci<p>The example below triggers all pending timers immediately,
20541cb0ef41Sopenharmony_cicausing them to execute without any delay.</p>
20551cb0ef41Sopenharmony_ci
20561cb0ef41Sopenharmony_ci<pre class="with-38-chars"><input class="js-flavor-selector" type="checkbox" checked aria-label="Show modern ES modules syntax"><code class="language-js mjs"><span class="hljs-keyword">import</span> assert <span class="hljs-keyword">from</span> <span class="hljs-string">'node:assert'</span>;
20571cb0ef41Sopenharmony_ci<span class="hljs-keyword">import</span> { test } <span class="hljs-keyword">from</span> <span class="hljs-string">'node:test'</span>;
20581cb0ef41Sopenharmony_ci
20591cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'runAll functions following the given order'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
20601cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
20611cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> results = [];
20621cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(<span class="hljs-function">() =></span> results.<span class="hljs-title function_">push</span>(<span class="hljs-number">1</span>), <span class="hljs-number">9999</span>);
20631cb0ef41Sopenharmony_ci
20641cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Notice that if both timers have the same timeout,</span>
20651cb0ef41Sopenharmony_ci  <span class="hljs-comment">// the order of execution is guaranteed</span>
20661cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(<span class="hljs-function">() =></span> results.<span class="hljs-title function_">push</span>(<span class="hljs-number">3</span>), <span class="hljs-number">8888</span>);
20671cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(<span class="hljs-function">() =></span> results.<span class="hljs-title function_">push</span>(<span class="hljs-number">2</span>), <span class="hljs-number">8888</span>);
20681cb0ef41Sopenharmony_ci
20691cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(results, []);
20701cb0ef41Sopenharmony_ci
20711cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">runAll</span>();
20721cb0ef41Sopenharmony_ci
20731cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(results, [<span class="hljs-number">3</span>, <span class="hljs-number">2</span>, <span class="hljs-number">1</span>]);
20741cb0ef41Sopenharmony_ci});</code><code class="language-js cjs"><span class="hljs-keyword">const</span> assert = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:assert'</span>);
20751cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> { test } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:test'</span>);
20761cb0ef41Sopenharmony_ci
20771cb0ef41Sopenharmony_ci<span class="hljs-title function_">test</span>(<span class="hljs-string">'runAll functions following the given order'</span>, <span class="hljs-function">(<span class="hljs-params">context</span>) =></span> {
20781cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">enable</span>([<span class="hljs-string">'setTimeout'</span>]);
20791cb0ef41Sopenharmony_ci  <span class="hljs-keyword">const</span> results = [];
20801cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(<span class="hljs-function">() =></span> results.<span class="hljs-title function_">push</span>(<span class="hljs-number">1</span>), <span class="hljs-number">9999</span>);
20811cb0ef41Sopenharmony_ci
20821cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Notice that if both timers have the same timeout,</span>
20831cb0ef41Sopenharmony_ci  <span class="hljs-comment">// the order of execution is guaranteed</span>
20841cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(<span class="hljs-function">() =></span> results.<span class="hljs-title function_">push</span>(<span class="hljs-number">3</span>), <span class="hljs-number">8888</span>);
20851cb0ef41Sopenharmony_ci  <span class="hljs-built_in">setTimeout</span>(<span class="hljs-function">() =></span> results.<span class="hljs-title function_">push</span>(<span class="hljs-number">2</span>), <span class="hljs-number">8888</span>);
20861cb0ef41Sopenharmony_ci
20871cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(results, []);
20881cb0ef41Sopenharmony_ci
20891cb0ef41Sopenharmony_ci  context.<span class="hljs-property">mock</span>.<span class="hljs-property">timers</span>.<span class="hljs-title function_">runAll</span>();
20901cb0ef41Sopenharmony_ci
20911cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">deepStrictEqual</span>(results, [<span class="hljs-number">3</span>, <span class="hljs-number">2</span>, <span class="hljs-number">1</span>]);
20921cb0ef41Sopenharmony_ci});</code><button class="copy-button">copy</button></pre>
20931cb0ef41Sopenharmony_ci<p><strong>Note:</strong> The <code>runAll()</code> function is specifically designed for
20941cb0ef41Sopenharmony_citriggering timers in the context of timer mocking.
20951cb0ef41Sopenharmony_ciIt does not have any effect on real-time system
20961cb0ef41Sopenharmony_ciclocks or actual timers outside of the mocking environment.</p>
20971cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>TestsStream</code><span><a class="mark" href="#class-testsstream" id="class-testsstream">#</a></span><a aria-hidden="true" class="legacy" id="test_class_testsstream"></a></h3>
20981cb0ef41Sopenharmony_ci<div class="api_metadata">
20991cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
21001cb0ef41Sopenharmony_ci<table>
21011cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
21021cb0ef41Sopenharmony_ci<tr><td>v18.17.0</td>
21031cb0ef41Sopenharmony_ci<td><p>added type to test:pass and test:fail events for when the test is a suite.</p></td></tr>
21041cb0ef41Sopenharmony_ci<tr><td>v18.9.0, v16.19.0</td>
21051cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.9.0, v16.19.0</span></p></td></tr>
21061cb0ef41Sopenharmony_ci</tbody></table>
21071cb0ef41Sopenharmony_ci</details>
21081cb0ef41Sopenharmony_ci</div>
21091cb0ef41Sopenharmony_ci<ul>
21101cb0ef41Sopenharmony_ci<li>Extends <a href="webstreams.html#class-readablestream" class="type">&#x3C;ReadableStream></a></li>
21111cb0ef41Sopenharmony_ci</ul>
21121cb0ef41Sopenharmony_ci<p>A successful call to <a href="#runoptions"><code>run()</code></a> method will return a new <a href="test.html#class-testsstream" class="type">&#x3C;TestsStream></a>
21131cb0ef41Sopenharmony_ciobject, streaming a series of events representing the execution of the tests.
21141cb0ef41Sopenharmony_ci<code>TestsStream</code> will emit events, in the order of the tests definition</p>
21151cb0ef41Sopenharmony_ci<h4>Event: <code>'test:coverage'</code><span><a class="mark" href="#event-testcoverage" id="event-testcoverage">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_coverage"></a></h4>
21161cb0ef41Sopenharmony_ci<ul>
21171cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
21181cb0ef41Sopenharmony_ci<ul>
21191cb0ef41Sopenharmony_ci<li><code>summary</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> An object containing the coverage report.
21201cb0ef41Sopenharmony_ci<ul>
21211cb0ef41Sopenharmony_ci<li><code>files</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a> An array of coverage reports for individual files. Each
21221cb0ef41Sopenharmony_cireport is an object with the following schema:
21231cb0ef41Sopenharmony_ci<ul>
21241cb0ef41Sopenharmony_ci<li><code>path</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The absolute path of the file.</li>
21251cb0ef41Sopenharmony_ci<li><code>totalLineCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The total number of lines.</li>
21261cb0ef41Sopenharmony_ci<li><code>totalBranchCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The total number of branches.</li>
21271cb0ef41Sopenharmony_ci<li><code>totalFunctionCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The total number of functions.</li>
21281cb0ef41Sopenharmony_ci<li><code>coveredLineCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of covered lines.</li>
21291cb0ef41Sopenharmony_ci<li><code>coveredBranchCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of covered branches.</li>
21301cb0ef41Sopenharmony_ci<li><code>coveredFunctionCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of covered functions.</li>
21311cb0ef41Sopenharmony_ci<li><code>coveredLinePercent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The percentage of lines covered.</li>
21321cb0ef41Sopenharmony_ci<li><code>coveredBranchPercent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The percentage of branches covered.</li>
21331cb0ef41Sopenharmony_ci<li><code>coveredFunctionPercent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The percentage of functions covered.</li>
21341cb0ef41Sopenharmony_ci<li><code>uncoveredLineNumbers</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type">&#x3C;Array></a> An array of integers representing line
21351cb0ef41Sopenharmony_cinumbers that are uncovered.</li>
21361cb0ef41Sopenharmony_ci</ul>
21371cb0ef41Sopenharmony_ci</li>
21381cb0ef41Sopenharmony_ci<li><code>totals</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> An object containing a summary of coverage for all
21391cb0ef41Sopenharmony_cifiles.
21401cb0ef41Sopenharmony_ci<ul>
21411cb0ef41Sopenharmony_ci<li><code>totalLineCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The total number of lines.</li>
21421cb0ef41Sopenharmony_ci<li><code>totalBranchCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The total number of branches.</li>
21431cb0ef41Sopenharmony_ci<li><code>totalFunctionCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The total number of functions.</li>
21441cb0ef41Sopenharmony_ci<li><code>coveredLineCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of covered lines.</li>
21451cb0ef41Sopenharmony_ci<li><code>coveredBranchCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of covered branches.</li>
21461cb0ef41Sopenharmony_ci<li><code>coveredFunctionCount</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of covered functions.</li>
21471cb0ef41Sopenharmony_ci<li><code>coveredLinePercent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The percentage of lines covered.</li>
21481cb0ef41Sopenharmony_ci<li><code>coveredBranchPercent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The percentage of branches covered.</li>
21491cb0ef41Sopenharmony_ci<li><code>coveredFunctionPercent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The percentage of functions covered.</li>
21501cb0ef41Sopenharmony_ci</ul>
21511cb0ef41Sopenharmony_ci</li>
21521cb0ef41Sopenharmony_ci<li><code>workingDirectory</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The working directory when code coverage
21531cb0ef41Sopenharmony_cibegan. This is useful for displaying relative path names in case the tests
21541cb0ef41Sopenharmony_cichanged the working directory of the Node.js process.</li>
21551cb0ef41Sopenharmony_ci</ul>
21561cb0ef41Sopenharmony_ci</li>
21571cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
21581cb0ef41Sopenharmony_ci</ul>
21591cb0ef41Sopenharmony_ci</li>
21601cb0ef41Sopenharmony_ci</ul>
21611cb0ef41Sopenharmony_ci<p>Emitted when code coverage is enabled and all tests have completed.</p>
21621cb0ef41Sopenharmony_ci<h4>Event: <code>'test:dequeue'</code><span><a class="mark" href="#event-testdequeue" id="event-testdequeue">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_dequeue"></a></h4>
21631cb0ef41Sopenharmony_ci<ul>
21641cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
21651cb0ef41Sopenharmony_ci<ul>
21661cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
21671cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
21681cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
21691cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
21701cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
21711cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
21721cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The test name.</li>
21731cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
21741cb0ef41Sopenharmony_ci</ul>
21751cb0ef41Sopenharmony_ci</li>
21761cb0ef41Sopenharmony_ci</ul>
21771cb0ef41Sopenharmony_ci<p>Emitted when a test is dequeued, right before it is executed.</p>
21781cb0ef41Sopenharmony_ci<h4>Event: <code>'test:diagnostic'</code><span><a class="mark" href="#event-testdiagnostic" id="event-testdiagnostic">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_diagnostic"></a></h4>
21791cb0ef41Sopenharmony_ci<ul>
21801cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
21811cb0ef41Sopenharmony_ci<ul>
21821cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
21831cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
21841cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
21851cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
21861cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
21871cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
21881cb0ef41Sopenharmony_ci<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The diagnostic message.</li>
21891cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
21901cb0ef41Sopenharmony_ci</ul>
21911cb0ef41Sopenharmony_ci</li>
21921cb0ef41Sopenharmony_ci</ul>
21931cb0ef41Sopenharmony_ci<p>Emitted when <a href="#contextdiagnosticmessage"><code>context.diagnostic</code></a> is called.</p>
21941cb0ef41Sopenharmony_ci<h4>Event: <code>'test:enqueue'</code><span><a class="mark" href="#event-testenqueue" id="event-testenqueue">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_enqueue"></a></h4>
21951cb0ef41Sopenharmony_ci<ul>
21961cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
21971cb0ef41Sopenharmony_ci<ul>
21981cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
21991cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22001cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
22011cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
22021cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
22031cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22041cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The test name.</li>
22051cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
22061cb0ef41Sopenharmony_ci</ul>
22071cb0ef41Sopenharmony_ci</li>
22081cb0ef41Sopenharmony_ci</ul>
22091cb0ef41Sopenharmony_ci<p>Emitted when a test is enqueued for execution.</p>
22101cb0ef41Sopenharmony_ci<h4>Event: <code>'test:fail'</code><span><a class="mark" href="#event-testfail" id="event-testfail">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_fail"></a></h4>
22111cb0ef41Sopenharmony_ci<ul>
22121cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
22131cb0ef41Sopenharmony_ci<ul>
22141cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
22151cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22161cb0ef41Sopenharmony_ci<li><code>details</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Additional execution metadata.
22171cb0ef41Sopenharmony_ci<ul>
22181cb0ef41Sopenharmony_ci<li><code>duration_ms</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The duration of the test in milliseconds.</li>
22191cb0ef41Sopenharmony_ci<li><code>error</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type">&#x3C;Error></a> An error wrapping the error thrown by the test.
22201cb0ef41Sopenharmony_ci<ul>
22211cb0ef41Sopenharmony_ci<li><code>cause</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type">&#x3C;Error></a> The actual error thrown by the test.</li>
22221cb0ef41Sopenharmony_ci</ul>
22231cb0ef41Sopenharmony_ci</li>
22241cb0ef41Sopenharmony_ci<li><code>type</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The type of the test, used to denote whether
22251cb0ef41Sopenharmony_cithis is a suite.</li>
22261cb0ef41Sopenharmony_ci</ul>
22271cb0ef41Sopenharmony_ci</li>
22281cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
22291cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
22301cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
22311cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22321cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The test name.</li>
22331cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
22341cb0ef41Sopenharmony_ci<li><code>testNumber</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The ordinal number of the test.</li>
22351cb0ef41Sopenharmony_ci<li><code>todo</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> Present if <a href="#contexttodomessage"><code>context.todo</code></a> is called</li>
22361cb0ef41Sopenharmony_ci<li><code>skip</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> Present if <a href="#contextskipmessage"><code>context.skip</code></a> is called</li>
22371cb0ef41Sopenharmony_ci</ul>
22381cb0ef41Sopenharmony_ci</li>
22391cb0ef41Sopenharmony_ci</ul>
22401cb0ef41Sopenharmony_ci<p>Emitted when a test fails.</p>
22411cb0ef41Sopenharmony_ci<h4>Event: <code>'test:pass'</code><span><a class="mark" href="#event-testpass" id="event-testpass">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_pass"></a></h4>
22421cb0ef41Sopenharmony_ci<ul>
22431cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
22441cb0ef41Sopenharmony_ci<ul>
22451cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
22461cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22471cb0ef41Sopenharmony_ci<li><code>details</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Additional execution metadata.
22481cb0ef41Sopenharmony_ci<ul>
22491cb0ef41Sopenharmony_ci<li><code>duration_ms</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The duration of the test in milliseconds.</li>
22501cb0ef41Sopenharmony_ci<li><code>type</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The type of the test, used to denote whether
22511cb0ef41Sopenharmony_cithis is a suite.</li>
22521cb0ef41Sopenharmony_ci</ul>
22531cb0ef41Sopenharmony_ci</li>
22541cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
22551cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
22561cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
22571cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22581cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The test name.</li>
22591cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
22601cb0ef41Sopenharmony_ci<li><code>testNumber</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The ordinal number of the test.</li>
22611cb0ef41Sopenharmony_ci<li><code>todo</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> Present if <a href="#contexttodomessage"><code>context.todo</code></a> is called</li>
22621cb0ef41Sopenharmony_ci<li><code>skip</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> Present if <a href="#contextskipmessage"><code>context.skip</code></a> is called</li>
22631cb0ef41Sopenharmony_ci</ul>
22641cb0ef41Sopenharmony_ci</li>
22651cb0ef41Sopenharmony_ci</ul>
22661cb0ef41Sopenharmony_ci<p>Emitted when a test passes.</p>
22671cb0ef41Sopenharmony_ci<h4>Event: <code>'test:plan'</code><span><a class="mark" href="#event-testplan" id="event-testplan">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_plan"></a></h4>
22681cb0ef41Sopenharmony_ci<ul>
22691cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
22701cb0ef41Sopenharmony_ci<ul>
22711cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
22721cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22731cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
22741cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
22751cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
22761cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22771cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
22781cb0ef41Sopenharmony_ci<li><code>count</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The number of subtests that have ran.</li>
22791cb0ef41Sopenharmony_ci</ul>
22801cb0ef41Sopenharmony_ci</li>
22811cb0ef41Sopenharmony_ci</ul>
22821cb0ef41Sopenharmony_ci<p>Emitted when all subtests have completed for a given test.</p>
22831cb0ef41Sopenharmony_ci<h4>Event: <code>'test:start'</code><span><a class="mark" href="#event-teststart" id="event-teststart">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_start"></a></h4>
22841cb0ef41Sopenharmony_ci<ul>
22851cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
22861cb0ef41Sopenharmony_ci<ul>
22871cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
22881cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22891cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The path of the test file,
22901cb0ef41Sopenharmony_ci<code>undefined</code> if test was run through the REPL.</li>
22911cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
22921cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
22931cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The test name.</li>
22941cb0ef41Sopenharmony_ci<li><code>nesting</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> The nesting level of the test.</li>
22951cb0ef41Sopenharmony_ci</ul>
22961cb0ef41Sopenharmony_ci</li>
22971cb0ef41Sopenharmony_ci</ul>
22981cb0ef41Sopenharmony_ci<p>Emitted when a test starts reporting its own and its subtests status.
22991cb0ef41Sopenharmony_ciThis event is guaranteed to be emitted in the same order as the tests are
23001cb0ef41Sopenharmony_cidefined.</p>
23011cb0ef41Sopenharmony_ci<h4>Event: <code>'test:stderr'</code><span><a class="mark" href="#event-teststderr" id="event-teststderr">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_stderr"></a></h4>
23021cb0ef41Sopenharmony_ci<ul>
23031cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
23041cb0ef41Sopenharmony_ci<ul>
23051cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
23061cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
23071cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The path of the test file.</li>
23081cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
23091cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
23101cb0ef41Sopenharmony_ci<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The message written to <code>stderr</code>.</li>
23111cb0ef41Sopenharmony_ci</ul>
23121cb0ef41Sopenharmony_ci</li>
23131cb0ef41Sopenharmony_ci</ul>
23141cb0ef41Sopenharmony_ci<p>Emitted when a running test writes to <code>stderr</code>.
23151cb0ef41Sopenharmony_ciThis event is only emitted if <code>--test</code> flag is passed.</p>
23161cb0ef41Sopenharmony_ci<h4>Event: <code>'test:stdout'</code><span><a class="mark" href="#event-teststdout" id="event-teststdout">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_stdout"></a></h4>
23171cb0ef41Sopenharmony_ci<ul>
23181cb0ef41Sopenharmony_ci<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
23191cb0ef41Sopenharmony_ci<ul>
23201cb0ef41Sopenharmony_ci<li><code>column</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The column number where the test is defined, or
23211cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
23221cb0ef41Sopenharmony_ci<li><code>file</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The path of the test file.</li>
23231cb0ef41Sopenharmony_ci<li><code>line</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type">&#x3C;undefined></a> The line number where the test is defined, or
23241cb0ef41Sopenharmony_ci<code>undefined</code> if the test was run through the REPL.</li>
23251cb0ef41Sopenharmony_ci<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The message written to <code>stdout</code>.</li>
23261cb0ef41Sopenharmony_ci</ul>
23271cb0ef41Sopenharmony_ci</li>
23281cb0ef41Sopenharmony_ci</ul>
23291cb0ef41Sopenharmony_ci<p>Emitted when a running test writes to <code>stdout</code>.
23301cb0ef41Sopenharmony_ciThis event is only emitted if <code>--test</code> flag is passed.</p>
23311cb0ef41Sopenharmony_ci<h4>Event: <code>'test:watch:drained'</code><span><a class="mark" href="#event-testwatchdrained" id="event-testwatchdrained">#</a></span><a aria-hidden="true" class="legacy" id="test_event_test_watch_drained"></a></h4>
23321cb0ef41Sopenharmony_ci<p>Emitted when no more tests are queued for execution in watch mode.</p>
23331cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>TestContext</code><span><a class="mark" href="#class-testcontext" id="class-testcontext">#</a></span><a aria-hidden="true" class="legacy" id="test_class_testcontext"></a></h3>
23341cb0ef41Sopenharmony_ci<div class="api_metadata">
23351cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
23361cb0ef41Sopenharmony_ci<table>
23371cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
23381cb0ef41Sopenharmony_ci<tr><td>v18.17.0</td>
23391cb0ef41Sopenharmony_ci<td><p>The <code>before</code> function was added to TestContext.</p></td></tr>
23401cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td>
23411cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.0.0</span></p></td></tr>
23421cb0ef41Sopenharmony_ci</tbody></table>
23431cb0ef41Sopenharmony_ci</details>
23441cb0ef41Sopenharmony_ci</div>
23451cb0ef41Sopenharmony_ci<p>An instance of <code>TestContext</code> is passed to each test function in order to
23461cb0ef41Sopenharmony_ciinteract with the test runner. However, the <code>TestContext</code> constructor is not
23471cb0ef41Sopenharmony_ciexposed as part of the API.</p>
23481cb0ef41Sopenharmony_ci<h4><code>context.before([fn][, options])</code><span><a class="mark" href="#contextbeforefn-options" id="contextbeforefn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_context_before_fn_options"></a></h4>
23491cb0ef41Sopenharmony_ci<div class="api_metadata">
23501cb0ef41Sopenharmony_ci<span>Added in: v18.17.0</span>
23511cb0ef41Sopenharmony_ci</div>
23521cb0ef41Sopenharmony_ci<ul>
23531cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function. The first argument
23541cb0ef41Sopenharmony_cito this function is a <a href="#class-testcontext"><code>TestContext</code></a> object. If the hook uses callbacks,
23551cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
23561cb0ef41Sopenharmony_cifunction.</li>
23571cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
23581cb0ef41Sopenharmony_ciproperties are supported:
23591cb0ef41Sopenharmony_ci<ul>
23601cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
23611cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
23621cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
23631cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
23641cb0ef41Sopenharmony_ci</ul>
23651cb0ef41Sopenharmony_ci</li>
23661cb0ef41Sopenharmony_ci</ul>
23671cb0ef41Sopenharmony_ci<p>This function is used to create a hook running before
23681cb0ef41Sopenharmony_cisubtest of the current test.</p>
23691cb0ef41Sopenharmony_ci<h4><code>context.beforeEach([fn][, options])</code><span><a class="mark" href="#contextbeforeeachfn-options" id="contextbeforeeachfn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_context_beforeeach_fn_options"></a></h4>
23701cb0ef41Sopenharmony_ci<div class="api_metadata">
23711cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
23721cb0ef41Sopenharmony_ci</div>
23731cb0ef41Sopenharmony_ci<ul>
23741cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function. The first argument
23751cb0ef41Sopenharmony_cito this function is a <a href="#class-testcontext"><code>TestContext</code></a> object. If the hook uses callbacks,
23761cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
23771cb0ef41Sopenharmony_cifunction.</li>
23781cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
23791cb0ef41Sopenharmony_ciproperties are supported:
23801cb0ef41Sopenharmony_ci<ul>
23811cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
23821cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
23831cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
23841cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
23851cb0ef41Sopenharmony_ci</ul>
23861cb0ef41Sopenharmony_ci</li>
23871cb0ef41Sopenharmony_ci</ul>
23881cb0ef41Sopenharmony_ci<p>This function is used to create a hook running
23891cb0ef41Sopenharmony_cibefore each subtest of the current test.</p>
23901cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
23911cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">beforeEach</span>(<span class="hljs-function">(<span class="hljs-params">t</span>) =></span> t.<span class="hljs-title function_">diagnostic</span>(<span class="hljs-string">`about to run <span class="hljs-subst">${t.name}</span>`</span>));
23921cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(
23931cb0ef41Sopenharmony_ci    <span class="hljs-string">'This is a subtest'</span>,
23941cb0ef41Sopenharmony_ci    <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
23951cb0ef41Sopenharmony_ci      assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
23961cb0ef41Sopenharmony_ci    },
23971cb0ef41Sopenharmony_ci  );
23981cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
23991cb0ef41Sopenharmony_ci<h4><code>context.after([fn][, options])</code><span><a class="mark" href="#contextafterfn-options" id="contextafterfn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_context_after_fn_options"></a></h4>
24001cb0ef41Sopenharmony_ci<div class="api_metadata">
24011cb0ef41Sopenharmony_ci<span>Added in: v18.13.0</span>
24021cb0ef41Sopenharmony_ci</div>
24031cb0ef41Sopenharmony_ci<ul>
24041cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function. The first argument
24051cb0ef41Sopenharmony_cito this function is a <a href="#class-testcontext"><code>TestContext</code></a> object. If the hook uses callbacks,
24061cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
24071cb0ef41Sopenharmony_cifunction.</li>
24081cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
24091cb0ef41Sopenharmony_ciproperties are supported:
24101cb0ef41Sopenharmony_ci<ul>
24111cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
24121cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
24131cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
24141cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
24151cb0ef41Sopenharmony_ci</ul>
24161cb0ef41Sopenharmony_ci</li>
24171cb0ef41Sopenharmony_ci</ul>
24181cb0ef41Sopenharmony_ci<p>This function is used to create a hook that runs after the current test
24191cb0ef41Sopenharmony_cifinishes.</p>
24201cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
24211cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">after</span>(<span class="hljs-function">(<span class="hljs-params">t</span>) =></span> t.<span class="hljs-title function_">diagnostic</span>(<span class="hljs-string">`finished running <span class="hljs-subst">${t.name}</span>`</span>));
24221cb0ef41Sopenharmony_ci  assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
24231cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
24241cb0ef41Sopenharmony_ci<h4><code>context.afterEach([fn][, options])</code><span><a class="mark" href="#contextaftereachfn-options" id="contextaftereachfn-options">#</a></span><a aria-hidden="true" class="legacy" id="test_context_aftereach_fn_options"></a></h4>
24251cb0ef41Sopenharmony_ci<div class="api_metadata">
24261cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
24271cb0ef41Sopenharmony_ci</div>
24281cb0ef41Sopenharmony_ci<ul>
24291cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The hook function. The first argument
24301cb0ef41Sopenharmony_cito this function is a <a href="#class-testcontext"><code>TestContext</code></a> object. If the hook uses callbacks,
24311cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
24321cb0ef41Sopenharmony_cifunction.</li>
24331cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the hook. The following
24341cb0ef41Sopenharmony_ciproperties are supported:
24351cb0ef41Sopenharmony_ci<ul>
24361cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress hook.</li>
24371cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the hook will fail after.
24381cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
24391cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
24401cb0ef41Sopenharmony_ci</ul>
24411cb0ef41Sopenharmony_ci</li>
24421cb0ef41Sopenharmony_ci</ul>
24431cb0ef41Sopenharmony_ci<p>This function is used to create a hook running
24441cb0ef41Sopenharmony_ciafter each subtest of the current test.</p>
24451cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
24461cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">afterEach</span>(<span class="hljs-function">(<span class="hljs-params">t</span>) =></span> t.<span class="hljs-title function_">diagnostic</span>(<span class="hljs-string">`finished running <span class="hljs-subst">${t.name}</span>`</span>));
24471cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(
24481cb0ef41Sopenharmony_ci    <span class="hljs-string">'This is a subtest'</span>,
24491cb0ef41Sopenharmony_ci    <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
24501cb0ef41Sopenharmony_ci      assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
24511cb0ef41Sopenharmony_ci    },
24521cb0ef41Sopenharmony_ci  );
24531cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
24541cb0ef41Sopenharmony_ci<h4><code>context.diagnostic(message)</code><span><a class="mark" href="#contextdiagnosticmessage" id="contextdiagnosticmessage">#</a></span><a aria-hidden="true" class="legacy" id="test_context_diagnostic_message"></a></h4>
24551cb0ef41Sopenharmony_ci<div class="api_metadata">
24561cb0ef41Sopenharmony_ci<span>Added in: v18.0.0</span>
24571cb0ef41Sopenharmony_ci</div>
24581cb0ef41Sopenharmony_ci<ul>
24591cb0ef41Sopenharmony_ci<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> Message to be reported.</li>
24601cb0ef41Sopenharmony_ci</ul>
24611cb0ef41Sopenharmony_ci<p>This function is used to write diagnostics to the output. Any diagnostic
24621cb0ef41Sopenharmony_ciinformation is included at the end of the test's results. This function does
24631cb0ef41Sopenharmony_cinot return a value.</p>
24641cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
24651cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">diagnostic</span>(<span class="hljs-string">'A diagnostic message'</span>);
24661cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
24671cb0ef41Sopenharmony_ci<h4><code>context.name</code><span><a class="mark" href="#contextname" id="contextname">#</a></span><a aria-hidden="true" class="legacy" id="test_context_name"></a></h4>
24681cb0ef41Sopenharmony_ci<div class="api_metadata">
24691cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
24701cb0ef41Sopenharmony_ci</div>
24711cb0ef41Sopenharmony_ci<p>The name of the test.</p>
24721cb0ef41Sopenharmony_ci<h4><code>context.runOnly(shouldRunOnlyTests)</code><span><a class="mark" href="#contextrunonlyshouldrunonlytests" id="contextrunonlyshouldrunonlytests">#</a></span><a aria-hidden="true" class="legacy" id="test_context_runonly_shouldrunonlytests"></a></h4>
24731cb0ef41Sopenharmony_ci<div class="api_metadata">
24741cb0ef41Sopenharmony_ci<span>Added in: v18.0.0</span>
24751cb0ef41Sopenharmony_ci</div>
24761cb0ef41Sopenharmony_ci<ul>
24771cb0ef41Sopenharmony_ci<li><code>shouldRunOnlyTests</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> Whether or not to run <code>only</code> tests.</li>
24781cb0ef41Sopenharmony_ci</ul>
24791cb0ef41Sopenharmony_ci<p>If <code>shouldRunOnlyTests</code> is truthy, the test context will only run tests that
24801cb0ef41Sopenharmony_cihave the <code>only</code> option set. Otherwise, all tests are run. If Node.js was not
24811cb0ef41Sopenharmony_cistarted with the <a href="cli.html#--test-only"><code>--test-only</code></a> command-line option, this function is a
24821cb0ef41Sopenharmony_cino-op.</p>
24831cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
24841cb0ef41Sopenharmony_ci  <span class="hljs-comment">// The test context can be set to run subtests with the 'only' option.</span>
24851cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">runOnly</span>(<span class="hljs-literal">true</span>);
24861cb0ef41Sopenharmony_ci  <span class="hljs-keyword">return</span> <span class="hljs-title class_">Promise</span>.<span class="hljs-title function_">all</span>([
24871cb0ef41Sopenharmony_ci    t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'this subtest is now skipped'</span>),
24881cb0ef41Sopenharmony_ci    t.<span class="hljs-title function_">test</span>(<span class="hljs-string">'this subtest is run'</span>, { <span class="hljs-attr">only</span>: <span class="hljs-literal">true</span> }),
24891cb0ef41Sopenharmony_ci  ]);
24901cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
24911cb0ef41Sopenharmony_ci<h4><code>context.signal</code><span><a class="mark" href="#contextsignal" id="contextsignal">#</a></span><a aria-hidden="true" class="legacy" id="test_context_signal"></a></h4>
24921cb0ef41Sopenharmony_ci<div class="api_metadata">
24931cb0ef41Sopenharmony_ci<span>Added in: v18.7.0</span>
24941cb0ef41Sopenharmony_ci</div>
24951cb0ef41Sopenharmony_ci<ul>
24961cb0ef41Sopenharmony_ci<li><a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Can be used to abort test subtasks when the test has been
24971cb0ef41Sopenharmony_ciaborted.</li>
24981cb0ef41Sopenharmony_ci</ul>
24991cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
25001cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> <span class="hljs-title function_">fetch</span>(<span class="hljs-string">'some/uri'</span>, { <span class="hljs-attr">signal</span>: t.<span class="hljs-property">signal</span> });
25011cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
25021cb0ef41Sopenharmony_ci<h4><code>context.skip([message])</code><span><a class="mark" href="#contextskipmessage" id="contextskipmessage">#</a></span><a aria-hidden="true" class="legacy" id="test_context_skip_message"></a></h4>
25031cb0ef41Sopenharmony_ci<div class="api_metadata">
25041cb0ef41Sopenharmony_ci<span>Added in: v18.0.0</span>
25051cb0ef41Sopenharmony_ci</div>
25061cb0ef41Sopenharmony_ci<ul>
25071cb0ef41Sopenharmony_ci<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> Optional skip message.</li>
25081cb0ef41Sopenharmony_ci</ul>
25091cb0ef41Sopenharmony_ci<p>This function causes the test's output to indicate the test as skipped. If
25101cb0ef41Sopenharmony_ci<code>message</code> is provided, it is included in the output. Calling <code>skip()</code> does
25111cb0ef41Sopenharmony_cinot terminate execution of the test function. This function does not return a
25121cb0ef41Sopenharmony_civalue.</p>
25131cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
25141cb0ef41Sopenharmony_ci  <span class="hljs-comment">// Make sure to return here as well if the test contains additional logic.</span>
25151cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">skip</span>(<span class="hljs-string">'this is skipped'</span>);
25161cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
25171cb0ef41Sopenharmony_ci<h4><code>context.todo([message])</code><span><a class="mark" href="#contexttodomessage" id="contexttodomessage">#</a></span><a aria-hidden="true" class="legacy" id="test_context_todo_message"></a></h4>
25181cb0ef41Sopenharmony_ci<div class="api_metadata">
25191cb0ef41Sopenharmony_ci<span>Added in: v18.0.0</span>
25201cb0ef41Sopenharmony_ci</div>
25211cb0ef41Sopenharmony_ci<ul>
25221cb0ef41Sopenharmony_ci<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> Optional <code>TODO</code> message.</li>
25231cb0ef41Sopenharmony_ci</ul>
25241cb0ef41Sopenharmony_ci<p>This function adds a <code>TODO</code> directive to the test's output. If <code>message</code> is
25251cb0ef41Sopenharmony_ciprovided, it is included in the output. Calling <code>todo()</code> does not terminate
25261cb0ef41Sopenharmony_ciexecution of the test function. This function does not return a value.</p>
25271cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
25281cb0ef41Sopenharmony_ci  <span class="hljs-comment">// This test is marked as `TODO`</span>
25291cb0ef41Sopenharmony_ci  t.<span class="hljs-title function_">todo</span>(<span class="hljs-string">'this is a todo'</span>);
25301cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
25311cb0ef41Sopenharmony_ci<h4><code>context.test([name][, options][, fn])</code><span><a class="mark" href="#contexttestname-options-fn" id="contexttestname-options-fn">#</a></span><a aria-hidden="true" class="legacy" id="test_context_test_name_options_fn"></a></h4>
25321cb0ef41Sopenharmony_ci<div class="api_metadata">
25331cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary>
25341cb0ef41Sopenharmony_ci<table>
25351cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr>
25361cb0ef41Sopenharmony_ci<tr><td>v18.8.0</td>
25371cb0ef41Sopenharmony_ci<td><p>Add a <code>signal</code> option.</p></td></tr>
25381cb0ef41Sopenharmony_ci<tr><td>v18.7.0</td>
25391cb0ef41Sopenharmony_ci<td><p>Add a <code>timeout</code> option.</p></td></tr>
25401cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td>
25411cb0ef41Sopenharmony_ci<td><p><span>Added in: v18.0.0</span></p></td></tr>
25421cb0ef41Sopenharmony_ci</tbody></table>
25431cb0ef41Sopenharmony_ci</details>
25441cb0ef41Sopenharmony_ci</div>
25451cb0ef41Sopenharmony_ci<ul>
25461cb0ef41Sopenharmony_ci<li><code>name</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The name of the subtest, which is displayed when reporting
25471cb0ef41Sopenharmony_citest results. <strong>Default:</strong> The <code>name</code> property of <code>fn</code>, or <code>'&#x3C;anonymous>'</code> if
25481cb0ef41Sopenharmony_ci<code>fn</code> does not have a name.</li>
25491cb0ef41Sopenharmony_ci<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Configuration options for the subtest. The following
25501cb0ef41Sopenharmony_ciproperties are supported:
25511cb0ef41Sopenharmony_ci<ul>
25521cb0ef41Sopenharmony_ci<li><code>concurrency</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Null_type" class="type">&#x3C;null></a> If a number is provided,
25531cb0ef41Sopenharmony_cithen that many tests would run in parallel within the application thread.
25541cb0ef41Sopenharmony_ciIf <code>true</code>, it would run all subtests in parallel.
25551cb0ef41Sopenharmony_ciIf <code>false</code>, it would only run one test at a time.
25561cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
25571cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>null</code>.</li>
25581cb0ef41Sopenharmony_ci<li><code>only</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If truthy, and the test context is configured to run
25591cb0ef41Sopenharmony_ci<code>only</code> tests, then this test will be run. Otherwise, the test is skipped.
25601cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>false</code>.</li>
25611cb0ef41Sopenharmony_ci<li><code>signal</code> <a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Allows aborting an in-progress test.</li>
25621cb0ef41Sopenharmony_ci<li><code>skip</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> If truthy, the test is skipped. If a string is
25631cb0ef41Sopenharmony_ciprovided, that string is displayed in the test results as the reason for
25641cb0ef41Sopenharmony_ciskipping the test. <strong>Default:</strong> <code>false</code>.</li>
25651cb0ef41Sopenharmony_ci<li><code>todo</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> If truthy, the test marked as <code>TODO</code>. If a string
25661cb0ef41Sopenharmony_ciis provided, that string is displayed in the test results as the reason why
25671cb0ef41Sopenharmony_cithe test is <code>TODO</code>. <strong>Default:</strong> <code>false</code>.</li>
25681cb0ef41Sopenharmony_ci<li><code>timeout</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> A number of milliseconds the test will fail after.
25691cb0ef41Sopenharmony_ciIf unspecified, subtests inherit this value from their parent.
25701cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>Infinity</code>.</li>
25711cb0ef41Sopenharmony_ci</ul>
25721cb0ef41Sopenharmony_ci</li>
25731cb0ef41Sopenharmony_ci<li><code>fn</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type">&#x3C;Function></a> | <a href="https://tc39.es/ecma262/#sec-async-function-constructor" class="type">&#x3C;AsyncFunction></a> The function under test. The first argument
25741cb0ef41Sopenharmony_cito this function is a <a href="#class-testcontext"><code>TestContext</code></a> object. If the test uses callbacks,
25751cb0ef41Sopenharmony_cithe callback function is passed as the second argument. <strong>Default:</strong> A no-op
25761cb0ef41Sopenharmony_cifunction.</li>
25771cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise" class="type">&#x3C;Promise></a> Resolved with <code>undefined</code> once the test completes.</li>
25781cb0ef41Sopenharmony_ci</ul>
25791cb0ef41Sopenharmony_ci<p>This function is used to create subtests under the current test. This function
25801cb0ef41Sopenharmony_cibehaves in the same fashion as the top level <a href="#testname-options-fn"><code>test()</code></a> function.</p>
25811cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-title function_">test</span>(<span class="hljs-string">'top level test'</span>, <span class="hljs-keyword">async</span> (t) => {
25821cb0ef41Sopenharmony_ci  <span class="hljs-keyword">await</span> t.<span class="hljs-title function_">test</span>(
25831cb0ef41Sopenharmony_ci    <span class="hljs-string">'This is a subtest'</span>,
25841cb0ef41Sopenharmony_ci    { <span class="hljs-attr">only</span>: <span class="hljs-literal">false</span>, <span class="hljs-attr">skip</span>: <span class="hljs-literal">false</span>, <span class="hljs-attr">concurrency</span>: <span class="hljs-number">1</span>, <span class="hljs-attr">todo</span>: <span class="hljs-literal">false</span> },
25851cb0ef41Sopenharmony_ci    <span class="hljs-function">(<span class="hljs-params">t</span>) =></span> {
25861cb0ef41Sopenharmony_ci      assert.<span class="hljs-title function_">ok</span>(<span class="hljs-string">'some relevant assertion here'</span>);
25871cb0ef41Sopenharmony_ci    },
25881cb0ef41Sopenharmony_ci  );
25891cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre>
25901cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>SuiteContext</code><span><a class="mark" href="#class-suitecontext" id="class-suitecontext">#</a></span><a aria-hidden="true" class="legacy" id="test_class_suitecontext"></a></h3>
25911cb0ef41Sopenharmony_ci<div class="api_metadata">
25921cb0ef41Sopenharmony_ci<span>Added in: v18.7.0</span>
25931cb0ef41Sopenharmony_ci</div>
25941cb0ef41Sopenharmony_ci<p>An instance of <code>SuiteContext</code> is passed to each suite function in order to
25951cb0ef41Sopenharmony_ciinteract with the test runner. However, the <code>SuiteContext</code> constructor is not
25961cb0ef41Sopenharmony_ciexposed as part of the API.</p>
25971cb0ef41Sopenharmony_ci<h4><code>context.name</code><span><a class="mark" href="#contextname_1" id="contextname_1">#</a></span><a aria-hidden="true" class="legacy" id="test_context_name_1"></a></h4>
25981cb0ef41Sopenharmony_ci<div class="api_metadata">
25991cb0ef41Sopenharmony_ci<span>Added in: v18.8.0</span>
26001cb0ef41Sopenharmony_ci</div>
26011cb0ef41Sopenharmony_ci<p>The name of the suite.</p>
26021cb0ef41Sopenharmony_ci<h4><code>context.signal</code><span><a class="mark" href="#contextsignal_1" id="contextsignal_1">#</a></span><a aria-hidden="true" class="legacy" id="test_context_signal_1"></a></h4>
26031cb0ef41Sopenharmony_ci<div class="api_metadata">
26041cb0ef41Sopenharmony_ci<span>Added in: v18.7.0</span>
26051cb0ef41Sopenharmony_ci</div>
26061cb0ef41Sopenharmony_ci<ul>
26071cb0ef41Sopenharmony_ci<li><a href="globals.html#class-abortsignal" class="type">&#x3C;AbortSignal></a> Can be used to abort test subtasks when the test has been
26081cb0ef41Sopenharmony_ciaborted.</li>
26091cb0ef41Sopenharmony_ci</ul></section>
26101cb0ef41Sopenharmony_ci        <!-- API END -->
26111cb0ef41Sopenharmony_ci      </div>
26121cb0ef41Sopenharmony_ci    </div>
26131cb0ef41Sopenharmony_ci  </div>
26141cb0ef41Sopenharmony_ci</body>
26151cb0ef41Sopenharmony_ci</html>
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