xref: /third_party/node/deps/npm/docs/content/using-npm/workspaces.md

---
title: workspaces
section: 7
description: Working with workspaces
---

### Description

**Workspaces** is a generic term that refers to the set of features in the
npm cli that provides support for managing multiple packages from your local
file system from within a singular top-level, root package.

This set of features makes up for a much more streamlined workflow handling
linked packages from the local file system. It automates the linking process
as part of `npm install` and removes the need to manually use `npm link` in
order to add references to packages that should be symlinked into the current
`node_modules` folder.

We also refer to these packages being auto-symlinked during `npm install` as a
single **workspace**, meaning it's a nested package within the current local
file system that is explicitly defined in the [`package.json`](/configuring-npm/package-json#workspaces)
`workspaces` configuration.

### Defining workspaces

Workspaces are usually defined via the `workspaces` property of the
[`package.json`](/configuring-npm/package-json#workspaces) file, e.g:

```json
{
  "name": "my-workspaces-powered-project",
  "workspaces": [
    "packages/a"
  ]
}
```

Given the above `package.json` example living at a current working
directory `.` that contains a folder named `packages/a` that itself contains
a `package.json` inside it, defining a Node.js package, e.g:

```
.
+-- package.json
`-- packages
   +-- a
   |   `-- package.json
```

The expected result once running `npm install` in this current working
directory `.` is that the folder `packages/a` will get symlinked to the
`node_modules` folder of the current working dir.

Below is a post `npm install` example, given that same previous example
structure of files and folders:

```
.
+-- node_modules
|  `-- a -> ../packages/a
+-- package-lock.json
+-- package.json
`-- packages
   +-- a
   |   `-- package.json
```

### Getting started with workspaces

You may automate the required steps to define a new workspace using
[npm init](/commands/npm-init). For example in a project that already has a
`package.json` defined you can run:

```
npm init -w ./packages/a
```

This command will create the missing folders and a new `package.json`
file (if needed) while also making sure to properly configure the
`"workspaces"` property of your root project `package.json`.

### Adding dependencies to a workspace

It's possible to directly add/remove/update dependencies of your workspaces
using the [`workspace` config](/using-npm/config#workspace).

For example, assuming the following structure:

```
.
+-- package.json
`-- packages
   +-- a
   |   `-- package.json
   `-- b
       `-- package.json
```

If you want to add a dependency named `abbrev` from the registry as a
dependency of your workspace **a**, you may use the workspace config to tell
the npm installer that package should be added as a dependency of the provided
workspace:

```
npm install abbrev -w a
```

Note: other installing commands such as `uninstall`, `ci`, etc will also
respect the provided `workspace` configuration.

### Using workspaces

Given the [specifics of how Node.js handles module resolution](https://nodejs.org/dist/latest-v14.x/docs/api/modules.html#modules_all_together) it's possible to consume any defined workspace
by its declared `package.json` `name`. Continuing from the example defined
above, let's also create a Node.js script that will require the workspace `a`
example module, e.g:

```
// ./packages/a/index.js
module.exports = 'a'

// ./lib/index.js
const moduleA = require('a')
console.log(moduleA) // -> a
```

When running it with:

`node lib/index.js`

This demonstrates how the nature of `node_modules` resolution allows for
**workspaces** to enable a portable workflow for requiring each **workspace**
in such a way that is also easy to [publish](/commands/npm-publish) these
nested workspaces to be consumed elsewhere.

### Running commands in the context of workspaces

You can use the `workspace` configuration option to run commands in the context
of a configured workspace.
Additionally, if your current directory is in a workspace, the `workspace`
configuration is implicitly set, and `prefix` is set to the root workspace.

Following is a quick example on how to use the `npm run` command in the context
of nested workspaces. For a project containing multiple workspaces, e.g:

```
.
+-- package.json
`-- packages
   +-- a
   |   `-- package.json
   `-- b
       `-- package.json
```

By running a command using the `workspace` option, it's possible to run the
given command in the context of that specific workspace. e.g:

```
npm run test --workspace=a
```

You could also run the command within the workspace.

```
cd packages/a && npm run test
```

Either will run the `test` script defined within the
`./packages/a/package.json` file.

Please note that you can also specify this argument multiple times in the
command-line in order to target multiple workspaces, e.g:

```
npm run test --workspace=a --workspace=b
```

Or run the command for each workspace within the 'packages' folder:
```
npm run test --workspace=packages
```

It's also possible to use the `workspaces` (plural) configuration option to
enable the same behavior but running that command in the context of **all**
configured workspaces. e.g:

```
npm run test --workspaces
```

Will run the `test` script in both `./packages/a` and `./packages/b`.

Commands will be run in each workspace in the order they appear in your `package.json`

```
{
  "workspaces": [ "packages/a", "packages/b" ]
}
```

Order of run is different with:

```
{
  "workspaces": [ "packages/b", "packages/a" ]
}
```

### Ignoring missing scripts

It is not required for all of the workspaces to implement scripts run with the `npm run` command.

By running the command with the `--if-present` flag, npm will ignore workspaces missing target script.

```
npm run test --workspaces --if-present
```

### See also

* [npm install](/commands/npm-install)
* [npm publish](/commands/npm-publish)
* [npm run-script](/commands/npm-run-script)
* [config](/using-npm/config)