EVOLUTION-MANAGER

Edit File: 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 to 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. Automating the linking process as part of `npm install` and avoiding manually having to 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 [specifities 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 ``` 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)