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1221cb0ef41Sopenharmony_ci <div class="picker"><div class="toc"><ul> 1231cb0ef41Sopenharmony_ci<li><span class="stability_2"><a href="#inspector">Inspector</a></span> 1241cb0ef41Sopenharmony_ci<ul> 1251cb0ef41Sopenharmony_ci<li><a href="#inspectorclose"><code>inspector.close()</code></a></li> 1261cb0ef41Sopenharmony_ci<li><a href="#inspectorconsole"><code>inspector.console</code></a></li> 1271cb0ef41Sopenharmony_ci<li><a href="#inspectoropenport-host-wait"><code>inspector.open([port[, host[, wait]]])</code></a></li> 1281cb0ef41Sopenharmony_ci<li><a href="#inspectorurl"><code>inspector.url()</code></a></li> 1291cb0ef41Sopenharmony_ci<li><a href="#inspectorwaitfordebugger"><code>inspector.waitForDebugger()</code></a></li> 1301cb0ef41Sopenharmony_ci<li><a href="#class-inspectorsession">Class: <code>inspector.Session</code></a> 1311cb0ef41Sopenharmony_ci<ul> 1321cb0ef41Sopenharmony_ci<li><a href="#new-inspectorsession"><code>new inspector.Session()</code></a></li> 1331cb0ef41Sopenharmony_ci<li><a href="#event-inspectornotification">Event: <code>'inspectorNotification'</code></a></li> 1341cb0ef41Sopenharmony_ci<li><a href="#event-inspector-protocol-method">Event: <code><inspector-protocol-method></code>;</a></li> 1351cb0ef41Sopenharmony_ci<li><a href="#sessionconnect"><code>session.connect()</code></a></li> 1361cb0ef41Sopenharmony_ci<li><a href="#sessionconnecttomainthread"><code>session.connectToMainThread()</code></a></li> 1371cb0ef41Sopenharmony_ci<li><a href="#sessiondisconnect"><code>session.disconnect()</code></a></li> 1381cb0ef41Sopenharmony_ci<li><a href="#sessionpostmethod-params-callback"><code>session.post(method[, params][, callback])</code></a> 1391cb0ef41Sopenharmony_ci<ul> 1401cb0ef41Sopenharmony_ci<li><a href="#example-usage">Example usage</a></li> 1411cb0ef41Sopenharmony_ci</ul> 1421cb0ef41Sopenharmony_ci</li> 1431cb0ef41Sopenharmony_ci<li><a href="#cpu-profiler">CPU profiler</a></li> 1441cb0ef41Sopenharmony_ci<li><a href="#heap-profiler">Heap profiler</a></li> 1451cb0ef41Sopenharmony_ci</ul> 1461cb0ef41Sopenharmony_ci</li> 1471cb0ef41Sopenharmony_ci</ul> 1481cb0ef41Sopenharmony_ci</li> 1491cb0ef41Sopenharmony_ci</ul></div></div> 1501cb0ef41Sopenharmony_ci </li> 1511cb0ef41Sopenharmony_ci 1521cb0ef41Sopenharmony_ci 1531cb0ef41Sopenharmony_ci <li class="picker-header"> 1541cb0ef41Sopenharmony_ci <a href="#"> 1551cb0ef41Sopenharmony_ci <span class="collapsed-arrow">►</span><span class="expanded-arrow">▼</span> 1561cb0ef41Sopenharmony_ci Index 1571cb0ef41Sopenharmony_ci </a> 1581cb0ef41Sopenharmony_ci 1591cb0ef41Sopenharmony_ci <div class="picker"><ul> 1601cb0ef41Sopenharmony_ci<li><a href="documentation.html" class="nav-documentation">About this documentation</a></li> 1611cb0ef41Sopenharmony_ci<li><a href="synopsis.html" class="nav-synopsis">Usage and example</a></li> 1621cb0ef41Sopenharmony_ci 1631cb0ef41Sopenharmony_ci <li> 1641cb0ef41Sopenharmony_ci <a href="index.html">Index</a> 1651cb0ef41Sopenharmony_ci </li> 1661cb0ef41Sopenharmony_ci </ul> 1671cb0ef41Sopenharmony_ci 1681cb0ef41Sopenharmony_ci<hr class="line"> 1691cb0ef41Sopenharmony_ci<ul> 1701cb0ef41Sopenharmony_ci<li><a href="assert.html" class="nav-assert">Assertion testing</a></li> 1711cb0ef41Sopenharmony_ci<li><a href="async_context.html" class="nav-async_context">Asynchronous context tracking</a></li> 1721cb0ef41Sopenharmony_ci<li><a href="async_hooks.html" class="nav-async_hooks">Async hooks</a></li> 1731cb0ef41Sopenharmony_ci<li><a href="buffer.html" class="nav-buffer">Buffer</a></li> 1741cb0ef41Sopenharmony_ci<li><a href="addons.html" class="nav-addons">C++ addons</a></li> 1751cb0ef41Sopenharmony_ci<li><a href="n-api.html" class="nav-n-api">C/C++ addons with Node-API</a></li> 1761cb0ef41Sopenharmony_ci<li><a href="embedding.html" class="nav-embedding">C++ embedder API</a></li> 1771cb0ef41Sopenharmony_ci<li><a href="child_process.html" class="nav-child_process">Child processes</a></li> 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2201cb0ef41Sopenharmony_ci<li><a href="dgram.html" class="nav-dgram">UDP/datagram</a></li> 2211cb0ef41Sopenharmony_ci<li><a href="url.html" class="nav-url">URL</a></li> 2221cb0ef41Sopenharmony_ci<li><a href="util.html" class="nav-util">Utilities</a></li> 2231cb0ef41Sopenharmony_ci<li><a href="v8.html" class="nav-v8">V8</a></li> 2241cb0ef41Sopenharmony_ci<li><a href="vm.html" class="nav-vm">VM</a></li> 2251cb0ef41Sopenharmony_ci<li><a href="wasi.html" class="nav-wasi">WASI</a></li> 2261cb0ef41Sopenharmony_ci<li><a href="webcrypto.html" class="nav-webcrypto">Web Crypto API</a></li> 2271cb0ef41Sopenharmony_ci<li><a href="webstreams.html" class="nav-webstreams">Web Streams API</a></li> 2281cb0ef41Sopenharmony_ci<li><a href="worker_threads.html" class="nav-worker_threads">Worker threads</a></li> 2291cb0ef41Sopenharmony_ci<li><a href="zlib.html" class="nav-zlib">Zlib</a></li> 2301cb0ef41Sopenharmony_ci</ul> 2311cb0ef41Sopenharmony_ci<hr class="line"> 2321cb0ef41Sopenharmony_ci<ul> 2331cb0ef41Sopenharmony_ci<li><a href="https://github.com/nodejs/node" class="nav-https-github-com-nodejs-node">Code repository and issue tracker</a></li> 2341cb0ef41Sopenharmony_ci</ul></div> 2351cb0ef41Sopenharmony_ci </li> 2361cb0ef41Sopenharmony_ci 2371cb0ef41Sopenharmony_ci 2381cb0ef41Sopenharmony_ci <li class="picker-header"> 2391cb0ef41Sopenharmony_ci <a href="#"> 2401cb0ef41Sopenharmony_ci <span class="collapsed-arrow">►</span><span class="expanded-arrow">▼</span> 2411cb0ef41Sopenharmony_ci Other versions 2421cb0ef41Sopenharmony_ci </a> 2431cb0ef41Sopenharmony_ci <div class="picker"><ol id="alt-docs"><li><a href="https://nodejs.org/docs/latest-v21.x/api/inspector.html">21.x</a></li> 2441cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v20.x/api/inspector.html">20.x <b>LTS</b></a></li> 2451cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v19.x/api/inspector.html">19.x</a></li> 2461cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v18.x/api/inspector.html">18.x <b>LTS</b></a></li> 2471cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v17.x/api/inspector.html">17.x</a></li> 2481cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v16.x/api/inspector.html">16.x</a></li> 2491cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v15.x/api/inspector.html">15.x</a></li> 2501cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v14.x/api/inspector.html">14.x</a></li> 2511cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v13.x/api/inspector.html">13.x</a></li> 2521cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v12.x/api/inspector.html">12.x</a></li> 2531cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v11.x/api/inspector.html">11.x</a></li> 2541cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v10.x/api/inspector.html">10.x</a></li> 2551cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v9.x/api/inspector.html">9.x</a></li> 2561cb0ef41Sopenharmony_ci<li><a href="https://nodejs.org/docs/latest-v8.x/api/inspector.html">8.x</a></li></ol></div> 2571cb0ef41Sopenharmony_ci </li> 2581cb0ef41Sopenharmony_ci 2591cb0ef41Sopenharmony_ci <li class="picker-header"> 2601cb0ef41Sopenharmony_ci <a href="#"> 2611cb0ef41Sopenharmony_ci <span class="collapsed-arrow">►</span><span class="expanded-arrow">▼</span> 2621cb0ef41Sopenharmony_ci Options 2631cb0ef41Sopenharmony_ci </a> 2641cb0ef41Sopenharmony_ci 2651cb0ef41Sopenharmony_ci <div class="picker"> 2661cb0ef41Sopenharmony_ci <ul> 2671cb0ef41Sopenharmony_ci <li> 2681cb0ef41Sopenharmony_ci <a href="all.html">View on single page</a> 2691cb0ef41Sopenharmony_ci </li> 2701cb0ef41Sopenharmony_ci <li> 2711cb0ef41Sopenharmony_ci <a href="inspector.json">View as JSON</a> 2721cb0ef41Sopenharmony_ci </li> 2731cb0ef41Sopenharmony_ci <li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/main/doc/api/inspector.md">Edit on GitHub</a></li> 2741cb0ef41Sopenharmony_ci </ul> 2751cb0ef41Sopenharmony_ci </div> 2761cb0ef41Sopenharmony_ci </li> 2771cb0ef41Sopenharmony_ci </ul> 2781cb0ef41Sopenharmony_ci </div> 2791cb0ef41Sopenharmony_ci <hr> 2801cb0ef41Sopenharmony_ci </header> 2811cb0ef41Sopenharmony_ci 2821cb0ef41Sopenharmony_ci <details id="toc" open><summary>Table of contents</summary><ul> 2831cb0ef41Sopenharmony_ci<li><span class="stability_2"><a href="#inspector">Inspector</a></span> 2841cb0ef41Sopenharmony_ci<ul> 2851cb0ef41Sopenharmony_ci<li><a href="#inspectorclose"><code>inspector.close()</code></a></li> 2861cb0ef41Sopenharmony_ci<li><a href="#inspectorconsole"><code>inspector.console</code></a></li> 2871cb0ef41Sopenharmony_ci<li><a href="#inspectoropenport-host-wait"><code>inspector.open([port[, host[, wait]]])</code></a></li> 2881cb0ef41Sopenharmony_ci<li><a href="#inspectorurl"><code>inspector.url()</code></a></li> 2891cb0ef41Sopenharmony_ci<li><a href="#inspectorwaitfordebugger"><code>inspector.waitForDebugger()</code></a></li> 2901cb0ef41Sopenharmony_ci<li><a href="#class-inspectorsession">Class: <code>inspector.Session</code></a> 2911cb0ef41Sopenharmony_ci<ul> 2921cb0ef41Sopenharmony_ci<li><a href="#new-inspectorsession"><code>new inspector.Session()</code></a></li> 2931cb0ef41Sopenharmony_ci<li><a href="#event-inspectornotification">Event: <code>'inspectorNotification'</code></a></li> 2941cb0ef41Sopenharmony_ci<li><a href="#event-inspector-protocol-method">Event: <code><inspector-protocol-method></code>;</a></li> 2951cb0ef41Sopenharmony_ci<li><a href="#sessionconnect"><code>session.connect()</code></a></li> 2961cb0ef41Sopenharmony_ci<li><a href="#sessionconnecttomainthread"><code>session.connectToMainThread()</code></a></li> 2971cb0ef41Sopenharmony_ci<li><a href="#sessiondisconnect"><code>session.disconnect()</code></a></li> 2981cb0ef41Sopenharmony_ci<li><a href="#sessionpostmethod-params-callback"><code>session.post(method[, params][, callback])</code></a> 2991cb0ef41Sopenharmony_ci<ul> 3001cb0ef41Sopenharmony_ci<li><a href="#example-usage">Example usage</a></li> 3011cb0ef41Sopenharmony_ci</ul> 3021cb0ef41Sopenharmony_ci</li> 3031cb0ef41Sopenharmony_ci<li><a href="#cpu-profiler">CPU profiler</a></li> 3041cb0ef41Sopenharmony_ci<li><a href="#heap-profiler">Heap profiler</a></li> 3051cb0ef41Sopenharmony_ci</ul> 3061cb0ef41Sopenharmony_ci</li> 3071cb0ef41Sopenharmony_ci</ul> 3081cb0ef41Sopenharmony_ci</li> 3091cb0ef41Sopenharmony_ci</ul></details> 3101cb0ef41Sopenharmony_ci 3111cb0ef41Sopenharmony_ci <div id="apicontent"> 3121cb0ef41Sopenharmony_ci <h2>Inspector<span><a class="mark" href="#inspector" id="inspector">#</a></span><a aria-hidden="true" class="legacy" id="inspector_inspector"></a></h2> 3131cb0ef41Sopenharmony_ci 3141cb0ef41Sopenharmony_ci<p></p><div class="api_stability api_stability_2"><a href="documentation.html#stability-index">Stability: 2</a> - Stable</div><p></p> 3151cb0ef41Sopenharmony_ci<p><strong>Source Code:</strong> <a href="https://github.com/nodejs/node/blob/v18.20.1/lib/inspector.js">lib/inspector.js</a></p> 3161cb0ef41Sopenharmony_ci<p>The <code>node:inspector</code> module provides an API for interacting with the V8 3171cb0ef41Sopenharmony_ciinspector.</p> 3181cb0ef41Sopenharmony_ci<p>It can be accessed using:</p> 3191cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> inspector = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:inspector'</span>);</code> <button class="copy-button">copy</button></pre> 3201cb0ef41Sopenharmony_ci<section><h3><code>inspector.close()</code><span><a class="mark" href="#inspectorclose" id="inspectorclose">#</a></span><a aria-hidden="true" class="legacy" id="inspector_inspector_close"></a></h3> 3211cb0ef41Sopenharmony_ci<div class="api_metadata"> 3221cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 3231cb0ef41Sopenharmony_ci<table> 3241cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 3251cb0ef41Sopenharmony_ci<tr><td>v18.10.0</td> 3261cb0ef41Sopenharmony_ci<td><p>The API is exposed in the worker threads.</p></td></tr> 3271cb0ef41Sopenharmony_ci<tr><td>v9.0.0</td> 3281cb0ef41Sopenharmony_ci<td><p><span>Added in: v9.0.0</span></p></td></tr> 3291cb0ef41Sopenharmony_ci</tbody></table> 3301cb0ef41Sopenharmony_ci</details> 3311cb0ef41Sopenharmony_ci</div> 3321cb0ef41Sopenharmony_ci<p>Deactivate the inspector. Blocks until there are no active connections.</p> 3331cb0ef41Sopenharmony_ci<p>When using <code>Session</code>, the object outputted by the console API will not be 3341cb0ef41Sopenharmony_cireleased, unless we performed manually <code>Runtime.DiscardConsoleEntries</code> 3351cb0ef41Sopenharmony_cicommand.</p> 3361cb0ef41Sopenharmony_ci</section><section><h3><code>inspector.console</code><span><a class="mark" href="#inspectorconsole" id="inspectorconsole">#</a></span><a aria-hidden="true" class="legacy" id="inspector_inspector_console"></a></h3> 3371cb0ef41Sopenharmony_ci<ul> 3381cb0ef41Sopenharmony_ci<li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> An object to send messages to the remote inspector console.</li> 3391cb0ef41Sopenharmony_ci</ul> 3401cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-built_in">require</span>(<span class="hljs-string">'node:inspector'</span>).<span class="hljs-property">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'a message'</span>);</code> <button class="copy-button">copy</button></pre> 3411cb0ef41Sopenharmony_ci<p>The inspector console does not have API parity with Node.js 3421cb0ef41Sopenharmony_ciconsole.</p> 3431cb0ef41Sopenharmony_ci</section><section><h3><code>inspector.open([port[, host[, wait]]])</code><span><a class="mark" href="#inspectoropenport-host-wait" id="inspectoropenport-host-wait">#</a></span><a aria-hidden="true" class="legacy" id="inspector_inspector_open_port_host_wait"></a></h3> 3441cb0ef41Sopenharmony_ci<ul> 3451cb0ef41Sopenharmony_ci<li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> Port to listen on for inspector connections. Optional. 3461cb0ef41Sopenharmony_ci<strong>Default:</strong> what was specified on the CLI.</li> 3471cb0ef41Sopenharmony_ci<li><code>host</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Host to listen on for inspector connections. Optional. 3481cb0ef41Sopenharmony_ci<strong>Default:</strong> what was specified on the CLI.</li> 3491cb0ef41Sopenharmony_ci<li><code>wait</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> Block until a client has connected. Optional. 3501cb0ef41Sopenharmony_ci<strong>Default:</strong> <code>false</code>.</li> 3511cb0ef41Sopenharmony_ci</ul> 3521cb0ef41Sopenharmony_ci<p>Activate inspector on host and port. Equivalent to 3531cb0ef41Sopenharmony_ci<code>node --inspect=[[host:]port]</code>, but can be done programmatically after node has 3541cb0ef41Sopenharmony_cistarted.</p> 3551cb0ef41Sopenharmony_ci<p>If wait is <code>true</code>, will block until a client has connected to the inspect port 3561cb0ef41Sopenharmony_ciand flow control has been passed to the debugger client.</p> 3571cb0ef41Sopenharmony_ci<p>See the <a href="cli.html#warning-binding-inspector-to-a-public-ipport-combination-is-insecure">security warning</a> regarding the <code>host</code> 3581cb0ef41Sopenharmony_ciparameter usage.</p> 3591cb0ef41Sopenharmony_ci</section><section><h3><code>inspector.url()</code><span><a class="mark" href="#inspectorurl" id="inspectorurl">#</a></span><a aria-hidden="true" class="legacy" id="inspector_inspector_url"></a></h3> 3601cb0ef41Sopenharmony_ci<ul> 3611cb0ef41Sopenharmony_ci<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Undefined_type" class="type"><undefined></a></li> 3621cb0ef41Sopenharmony_ci</ul> 3631cb0ef41Sopenharmony_ci<p>Return the URL of the active inspector, or <code>undefined</code> if there is none.</p> 3641cb0ef41Sopenharmony_ci<pre><code class="language-console"><span class="hljs-meta prompt_">$ </span><span class="language-bash">node --inspect -p <span class="hljs-string">'inspector.url()'</span></span> 3651cb0ef41Sopenharmony_ciDebugger listening on ws://127.0.0.1:9229/166e272e-7a30-4d09-97ce-f1c012b43c34 3661cb0ef41Sopenharmony_ciFor help, see: https://nodejs.org/en/docs/inspector 3671cb0ef41Sopenharmony_ciws://127.0.0.1:9229/166e272e-7a30-4d09-97ce-f1c012b43c34 3681cb0ef41Sopenharmony_ci<span class="hljs-meta prompt_"> 3691cb0ef41Sopenharmony_ci$ </span><span class="language-bash">node --inspect=localhost:3000 -p <span class="hljs-string">'inspector.url()'</span></span> 3701cb0ef41Sopenharmony_ciDebugger listening on ws://localhost:3000/51cf8d0e-3c36-4c59-8efd-54519839e56a 3711cb0ef41Sopenharmony_ciFor help, see: https://nodejs.org/en/docs/inspector 3721cb0ef41Sopenharmony_ciws://localhost:3000/51cf8d0e-3c36-4c59-8efd-54519839e56a 3731cb0ef41Sopenharmony_ci<span class="hljs-meta prompt_"> 3741cb0ef41Sopenharmony_ci$ </span><span class="language-bash">node -p <span class="hljs-string">'inspector.url()'</span></span> 3751cb0ef41Sopenharmony_ciundefined</code> <button class="copy-button">copy</button></pre> 3761cb0ef41Sopenharmony_ci</section><section><h3><code>inspector.waitForDebugger()</code><span><a class="mark" href="#inspectorwaitfordebugger" id="inspectorwaitfordebugger">#</a></span><a aria-hidden="true" class="legacy" id="inspector_inspector_waitfordebugger"></a></h3> 3771cb0ef41Sopenharmony_ci<div class="api_metadata"> 3781cb0ef41Sopenharmony_ci<span>Added in: v12.7.0</span> 3791cb0ef41Sopenharmony_ci</div> 3801cb0ef41Sopenharmony_ci<p>Blocks until a client (existing or connected later) has sent 3811cb0ef41Sopenharmony_ci<code>Runtime.runIfWaitingForDebugger</code> command.</p> 3821cb0ef41Sopenharmony_ci<p>An exception will be thrown if there is no active inspector.</p> 3831cb0ef41Sopenharmony_ci</section><section><h3>Class: <code>inspector.Session</code><span><a class="mark" href="#class-inspectorsession" id="class-inspectorsession">#</a></span><a aria-hidden="true" class="legacy" id="inspector_class_inspector_session"></a></h3> 3841cb0ef41Sopenharmony_ci<ul> 3851cb0ef41Sopenharmony_ci<li>Extends: <a href="events.html#class-eventemitter" class="type"><EventEmitter></a></li> 3861cb0ef41Sopenharmony_ci</ul> 3871cb0ef41Sopenharmony_ci<p>The <code>inspector.Session</code> is used for dispatching messages to the V8 inspector 3881cb0ef41Sopenharmony_ciback-end and receiving message responses and notifications.</p> 3891cb0ef41Sopenharmony_ci<h4><code>new inspector.Session()</code><span><a class="mark" href="#new-inspectorsession" id="new-inspectorsession">#</a></span><a aria-hidden="true" class="legacy" id="inspector_new_inspector_session"></a></h4> 3901cb0ef41Sopenharmony_ci<div class="api_metadata"> 3911cb0ef41Sopenharmony_ci<span>Added in: v8.0.0</span> 3921cb0ef41Sopenharmony_ci</div> 3931cb0ef41Sopenharmony_ci<p>Create a new instance of the <code>inspector.Session</code> class. The inspector session 3941cb0ef41Sopenharmony_cineeds to be connected through <a href="#sessionconnect"><code>session.connect()</code></a> before the messages 3951cb0ef41Sopenharmony_cican be dispatched to the inspector backend.</p> 3961cb0ef41Sopenharmony_ci<p>When using <code>Session</code>, the object outputted by the console API will not be 3971cb0ef41Sopenharmony_cireleased, unless we performed manually <code>Runtime.DiscardConsoleEntries</code> 3981cb0ef41Sopenharmony_cicommand.</p> 3991cb0ef41Sopenharmony_ci<h4>Event: <code>'inspectorNotification'</code><span><a class="mark" href="#event-inspectornotification" id="event-inspectornotification">#</a></span><a aria-hidden="true" class="legacy" id="inspector_event_inspectornotification"></a></h4> 4001cb0ef41Sopenharmony_ci<div class="api_metadata"> 4011cb0ef41Sopenharmony_ci<span>Added in: v8.0.0</span> 4021cb0ef41Sopenharmony_ci</div> 4031cb0ef41Sopenharmony_ci<ul> 4041cb0ef41Sopenharmony_ci<li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> The notification message object</li> 4051cb0ef41Sopenharmony_ci</ul> 4061cb0ef41Sopenharmony_ci<p>Emitted when any notification from the V8 Inspector is received.</p> 4071cb0ef41Sopenharmony_ci<pre><code class="language-js">session.<span class="hljs-title function_">on</span>(<span class="hljs-string">'inspectorNotification'</span>, <span class="hljs-function">(<span class="hljs-params">message</span>) =></span> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(message.<span class="hljs-property">method</span>)); 4081cb0ef41Sopenharmony_ci<span class="hljs-comment">// Debugger.paused</span> 4091cb0ef41Sopenharmony_ci<span class="hljs-comment">// Debugger.resumed</span></code> <button class="copy-button">copy</button></pre> 4101cb0ef41Sopenharmony_ci<p>It is also possible to subscribe only to notifications with specific method:</p> 4111cb0ef41Sopenharmony_ci<h4>Event: <code><inspector-protocol-method></code>;<span><a class="mark" href="#event-inspector-protocol-method" id="event-inspector-protocol-method">#</a></span><a aria-hidden="true" class="legacy" id="inspector_event_inspector_protocol_method"></a></h4> 4121cb0ef41Sopenharmony_ci<div class="api_metadata"> 4131cb0ef41Sopenharmony_ci<span>Added in: v8.0.0</span> 4141cb0ef41Sopenharmony_ci</div> 4151cb0ef41Sopenharmony_ci<ul> 4161cb0ef41Sopenharmony_ci<li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> The notification message object</li> 4171cb0ef41Sopenharmony_ci</ul> 4181cb0ef41Sopenharmony_ci<p>Emitted when an inspector notification is received that has its method field set 4191cb0ef41Sopenharmony_cito the <code><inspector-protocol-method></code> value.</p> 4201cb0ef41Sopenharmony_ci<p>The following snippet installs a listener on the <a href="https://chromedevtools.github.io/devtools-protocol/v8/Debugger#event-paused"><code>'Debugger.paused'</code></a> 4211cb0ef41Sopenharmony_cievent, and prints the reason for program suspension whenever program 4221cb0ef41Sopenharmony_ciexecution is suspended (through breakpoints, for example):</p> 4231cb0ef41Sopenharmony_ci<pre><code class="language-js">session.<span class="hljs-title function_">on</span>(<span class="hljs-string">'Debugger.paused'</span>, <span class="hljs-function">(<span class="hljs-params">{ params }</span>) =></span> { 4241cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(params.<span class="hljs-property">hitBreakpoints</span>); 4251cb0ef41Sopenharmony_ci}); 4261cb0ef41Sopenharmony_ci<span class="hljs-comment">// [ '/the/file/that/has/the/breakpoint.js:11:0' ]</span></code> <button class="copy-button">copy</button></pre> 4271cb0ef41Sopenharmony_ci<h4><code>session.connect()</code><span><a class="mark" href="#sessionconnect" id="sessionconnect">#</a></span><a aria-hidden="true" class="legacy" id="inspector_session_connect"></a></h4> 4281cb0ef41Sopenharmony_ci<div class="api_metadata"> 4291cb0ef41Sopenharmony_ci<span>Added in: v8.0.0</span> 4301cb0ef41Sopenharmony_ci</div> 4311cb0ef41Sopenharmony_ci<p>Connects a session to the inspector back-end.</p> 4321cb0ef41Sopenharmony_ci<h4><code>session.connectToMainThread()</code><span><a class="mark" href="#sessionconnecttomainthread" id="sessionconnecttomainthread">#</a></span><a aria-hidden="true" class="legacy" id="inspector_session_connecttomainthread"></a></h4> 4331cb0ef41Sopenharmony_ci<div class="api_metadata"> 4341cb0ef41Sopenharmony_ci<span>Added in: v12.11.0</span> 4351cb0ef41Sopenharmony_ci</div> 4361cb0ef41Sopenharmony_ci<p>Connects a session to the main thread inspector back-end. An exception will 4371cb0ef41Sopenharmony_cibe thrown if this API was not called on a Worker thread.</p> 4381cb0ef41Sopenharmony_ci<h4><code>session.disconnect()</code><span><a class="mark" href="#sessiondisconnect" id="sessiondisconnect">#</a></span><a aria-hidden="true" class="legacy" id="inspector_session_disconnect"></a></h4> 4391cb0ef41Sopenharmony_ci<div class="api_metadata"> 4401cb0ef41Sopenharmony_ci<span>Added in: v8.0.0</span> 4411cb0ef41Sopenharmony_ci</div> 4421cb0ef41Sopenharmony_ci<p>Immediately close the session. All pending message callbacks will be called 4431cb0ef41Sopenharmony_ciwith an error. <a href="#sessionconnect"><code>session.connect()</code></a> will need to be called to be able to send 4441cb0ef41Sopenharmony_cimessages again. Reconnected session will lose all inspector state, such as 4451cb0ef41Sopenharmony_cienabled agents or configured breakpoints.</p> 4461cb0ef41Sopenharmony_ci<h4><code>session.post(method[, params][, callback])</code><span><a class="mark" href="#sessionpostmethod-params-callback" id="sessionpostmethod-params-callback">#</a></span><a aria-hidden="true" class="legacy" id="inspector_session_post_method_params_callback"></a></h4> 4471cb0ef41Sopenharmony_ci<div class="api_metadata"> 4481cb0ef41Sopenharmony_ci<details class="changelog"><summary>History</summary> 4491cb0ef41Sopenharmony_ci<table> 4501cb0ef41Sopenharmony_ci<tbody><tr><th>Version</th><th>Changes</th></tr> 4511cb0ef41Sopenharmony_ci<tr><td>v18.0.0</td> 4521cb0ef41Sopenharmony_ci<td><p>Passing an invalid callback to the <code>callback</code> argument now throws <code>ERR_INVALID_ARG_TYPE</code> instead of <code>ERR_INVALID_CALLBACK</code>.</p></td></tr> 4531cb0ef41Sopenharmony_ci<tr><td>v8.0.0</td> 4541cb0ef41Sopenharmony_ci<td><p><span>Added in: v8.0.0</span></p></td></tr> 4551cb0ef41Sopenharmony_ci</tbody></table> 4561cb0ef41Sopenharmony_ci</details> 4571cb0ef41Sopenharmony_ci</div> 4581cb0ef41Sopenharmony_ci<ul> 4591cb0ef41Sopenharmony_ci<li><code>method</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> 4601cb0ef41Sopenharmony_ci<li><code>params</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></li> 4611cb0ef41Sopenharmony_ci<li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a></li> 4621cb0ef41Sopenharmony_ci</ul> 4631cb0ef41Sopenharmony_ci<p>Posts a message to the inspector back-end. <code>callback</code> will be notified when 4641cb0ef41Sopenharmony_cia response is received. <code>callback</code> is a function that accepts two optional 4651cb0ef41Sopenharmony_ciarguments: error and message-specific result.</p> 4661cb0ef41Sopenharmony_ci<pre><code class="language-js">session.<span class="hljs-title function_">post</span>(<span class="hljs-string">'Runtime.evaluate'</span>, { <span class="hljs-attr">expression</span>: <span class="hljs-string">'2 + 2'</span> }, 4671cb0ef41Sopenharmony_ci <span class="hljs-function">(<span class="hljs-params">error, { result }</span>) =></span> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(result)); 4681cb0ef41Sopenharmony_ci<span class="hljs-comment">// Output: { type: 'number', value: 4, description: '4' }</span></code> <button class="copy-button">copy</button></pre> 4691cb0ef41Sopenharmony_ci<p>The latest version of the V8 inspector protocol is published on the 4701cb0ef41Sopenharmony_ci<a href="https://chromedevtools.github.io/devtools-protocol/v8/">Chrome DevTools Protocol Viewer</a>.</p> 4711cb0ef41Sopenharmony_ci<p>Node.js inspector supports all the Chrome DevTools Protocol domains declared 4721cb0ef41Sopenharmony_ciby V8. Chrome DevTools Protocol domain provides an interface for interacting 4731cb0ef41Sopenharmony_ciwith one of the runtime agents used to inspect the application state and listen 4741cb0ef41Sopenharmony_cito the run-time events.</p> 4751cb0ef41Sopenharmony_ci<p>You can not set <code>reportProgress</code> to <code>true</code> when sending a 4761cb0ef41Sopenharmony_ci<code>HeapProfiler.takeHeapSnapshot</code> or <code>HeapProfiler.stopTrackingHeapObjects</code> 4771cb0ef41Sopenharmony_cicommand to V8.</p> 4781cb0ef41Sopenharmony_ci<h5>Example usage<span><a class="mark" href="#example-usage" id="example-usage">#</a></span><a aria-hidden="true" class="legacy" id="inspector_example_usage"></a></h5> 4791cb0ef41Sopenharmony_ci<p>Apart from the debugger, various V8 Profilers are available through the DevTools 4801cb0ef41Sopenharmony_ciprotocol.</p> 4811cb0ef41Sopenharmony_ci<h4>CPU profiler<span><a class="mark" href="#cpu-profiler" id="cpu-profiler">#</a></span><a aria-hidden="true" class="legacy" id="inspector_cpu_profiler"></a></h4> 4821cb0ef41Sopenharmony_ci<p>Here's an example showing how to use the <a href="https://chromedevtools.github.io/devtools-protocol/v8/Profiler">CPU Profiler</a>:</p> 4831cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> inspector = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:inspector'</span>); 4841cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> fs = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:fs'</span>); 4851cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> session = <span class="hljs-keyword">new</span> inspector.<span class="hljs-title class_">Session</span>(); 4861cb0ef41Sopenharmony_cisession.<span class="hljs-title function_">connect</span>(); 4871cb0ef41Sopenharmony_ci 4881cb0ef41Sopenharmony_cisession.<span class="hljs-title function_">post</span>(<span class="hljs-string">'Profiler.enable'</span>, <span class="hljs-function">() =></span> { 4891cb0ef41Sopenharmony_ci session.<span class="hljs-title function_">post</span>(<span class="hljs-string">'Profiler.start'</span>, <span class="hljs-function">() =></span> { 4901cb0ef41Sopenharmony_ci <span class="hljs-comment">// Invoke business logic under measurement here...</span> 4911cb0ef41Sopenharmony_ci 4921cb0ef41Sopenharmony_ci <span class="hljs-comment">// some time later...</span> 4931cb0ef41Sopenharmony_ci session.<span class="hljs-title function_">post</span>(<span class="hljs-string">'Profiler.stop'</span>, <span class="hljs-function">(<span class="hljs-params">err, { profile }</span>) =></span> { 4941cb0ef41Sopenharmony_ci <span class="hljs-comment">// Write profile to disk, upload, etc.</span> 4951cb0ef41Sopenharmony_ci <span class="hljs-keyword">if</span> (!err) { 4961cb0ef41Sopenharmony_ci fs.<span class="hljs-title function_">writeFileSync</span>(<span class="hljs-string">'./profile.cpuprofile'</span>, <span class="hljs-title class_">JSON</span>.<span class="hljs-title function_">stringify</span>(profile)); 4971cb0ef41Sopenharmony_ci } 4981cb0ef41Sopenharmony_ci }); 4991cb0ef41Sopenharmony_ci }); 5001cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre> 5011cb0ef41Sopenharmony_ci<h4>Heap profiler<span><a class="mark" href="#heap-profiler" id="heap-profiler">#</a></span><a aria-hidden="true" class="legacy" id="inspector_heap_profiler"></a></h4> 5021cb0ef41Sopenharmony_ci<p>Here's an example showing how to use the <a href="https://chromedevtools.github.io/devtools-protocol/v8/HeapProfiler">Heap Profiler</a>:</p> 5031cb0ef41Sopenharmony_ci<pre><code class="language-js"><span class="hljs-keyword">const</span> inspector = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:inspector'</span>); 5041cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> fs = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:fs'</span>); 5051cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> session = <span class="hljs-keyword">new</span> inspector.<span class="hljs-title class_">Session</span>(); 5061cb0ef41Sopenharmony_ci 5071cb0ef41Sopenharmony_ci<span class="hljs-keyword">const</span> fd = fs.<span class="hljs-title function_">openSync</span>(<span class="hljs-string">'profile.heapsnapshot'</span>, <span class="hljs-string">'w'</span>); 5081cb0ef41Sopenharmony_ci 5091cb0ef41Sopenharmony_cisession.<span class="hljs-title function_">connect</span>(); 5101cb0ef41Sopenharmony_ci 5111cb0ef41Sopenharmony_cisession.<span class="hljs-title function_">on</span>(<span class="hljs-string">'HeapProfiler.addHeapSnapshotChunk'</span>, <span class="hljs-function">(<span class="hljs-params">m</span>) =></span> { 5121cb0ef41Sopenharmony_ci fs.<span class="hljs-title function_">writeSync</span>(fd, m.<span class="hljs-property">params</span>.<span class="hljs-property">chunk</span>); 5131cb0ef41Sopenharmony_ci}); 5141cb0ef41Sopenharmony_ci 5151cb0ef41Sopenharmony_cisession.<span class="hljs-title function_">post</span>(<span class="hljs-string">'HeapProfiler.takeHeapSnapshot'</span>, <span class="hljs-literal">null</span>, <span class="hljs-function">(<span class="hljs-params">err, r</span>) =></span> { 5161cb0ef41Sopenharmony_ci <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'HeapProfiler.takeHeapSnapshot done:'</span>, err, r); 5171cb0ef41Sopenharmony_ci session.<span class="hljs-title function_">disconnect</span>(); 5181cb0ef41Sopenharmony_ci fs.<span class="hljs-title function_">closeSync</span>(fd); 5191cb0ef41Sopenharmony_ci});</code> <button class="copy-button">copy</button></pre></section> 5201cb0ef41Sopenharmony_ci <!-- API END --> 5211cb0ef41Sopenharmony_ci </div> 5221cb0ef41Sopenharmony_ci </div> 5231cb0ef41Sopenharmony_ci </div> 5241cb0ef41Sopenharmony_ci</body> 5251cb0ef41Sopenharmony_ci</html> 526