Yarn

https://github.com/yarnpkg/website
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### Install and serve the website using make

Source: https://github.com/yarnpkg/website/blob/master/README.md

Commands to install dependencies and start the local development server.

```sh
$ make install
$ make serve
```

--------------------------------

### Install package using tags

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/tag.md

Examples of installing a package using specific distribution tags.

```sh
yarn add your-package-name@stable
yarn add your-package-name@canary
```

--------------------------------

### Install packages from various locations

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/add.md

Examples of installing packages from local paths, tarballs, symlinks, and git repositories.

```sh
yarn add package-name
yarn add file:/path/to/local/folder
yarn add file:/path/to/local/tarball.tgz
yarn add link:/path/to/local/folder
yarn add <git remote url>
yarn add <git remote url>#<branch/commit/tag>
yarn add https://my-project.org/package.tgz
```

--------------------------------

### Install specific package versions

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/add.md

Examples of installing specific versions or tags of a package.

```sh
yarn add package-name
yarn add package-name@1.2.3
yarn add package-name@tag
```

--------------------------------

### Example .gitlab-ci.yml for testing

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_ci/gitlab.md

A complete example configuration that installs dependencies using a cache folder and runs a test suite.

```yaml
# .gitlab-ci.yml
image: node:9.11.1

before_script:
  - yarn install --cache-folder .yarn

test:
  stage: test
  cache:
    paths:
    - node_modules/
    - .yarn
```

--------------------------------

### Configure directories

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/package-json.md

Specifies exact locations for binary files, man pages, documentation, and examples during package installation.

```json
{
  "directories": {
    "lib": "path/to/lib/",
    "bin": "path/to/bin/",
    "man": "path/to/man/",
    "doc": "path/to/doc/",
    "example": "path/to/example/"
  }
}
```

--------------------------------

### Install all dependencies with yarn or yarn install

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/usage.md

Run either command to install all dependencies listed in your package.json.

```sh
yarn
```

```sh
yarn install
```

--------------------------------

### Example package.json configuration

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/configuration.md

An example configuration for the pet-kitten package, which would be found at pet-kitten/package.json.

```json
{
  "name": "pet-kitten",
  "version": "0.1.0",
  "main": "pet.js",
  "dependencies": {
    "hand": "1.0.0"
  }
}
```

--------------------------------

### Setup commands for Semaphore Project Settings

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_ci/semaphore.md

Add these commands to your setup commands in Project Settings to ensure your local Yarn version matches the one on Semaphore. The commands add the Yarn APT repository and use install-package to cache APT installations, with an optional version specification.

```sh
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb http://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
# install-package is a tool for caching APT installations in Semaphore
# defining a package version is optional
install-package --update-new yarn=<version>
```

--------------------------------

### Example output of yarn why

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/why.md

Example output from `yarn why jest` showing the steps and information about why the module is installed, including hoisting, dependency source, and disk size statistics.

```text
yarn why vx.x.x
[1/4] 🤔  Why do we have the module "jest"...?
[2/4] 🚚  Initializing dependency graph...
[3/4] 🔍  Finding dependency...
[4/4] 🚡  Calculating file sizes...
info Has been hoisted to "jest"
info This module exists because it's specified in "devDependencies".
info Disk size without dependencies: "1.29kB"
info Disk size with unique dependencies: "101.31kB"
info Disk size with transitive dependencies: "20.35MB"
info Amount of shared dependencies: 125
```

--------------------------------

### Add specific versions and tags example

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/managing-dependencies.md

Examples of adding packages with specific versions or tags, followed by the resulting package.json structure.

```sh
yarn add package-1@1.2.3
yarn add package-2@^1.0.0
yarn add package-3@beta
```

```json
{
  "dependencies": {
    "package-1": "1.2.3",
    "package-2": "^1.0.0",
    "package-3": "beta"
  }
}
```

--------------------------------

### Install Yarn with apt

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/debian.md

Updates the package list and installs Yarn using apt.

```sh
sudo apt update && sudo apt install yarn

```

--------------------------------

### Install Node.js via Scoop

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/windows.md

If Node.js is not installed, Scoop will suggest this command to install it.

```sh
scoop install nodejs
```

--------------------------------

### Install a package

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/add.md

Installs the latest version of a package from the npm registry.

```sh
yarn add react
```

--------------------------------

### Install Yarn via Scoop

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/windows.md

Run this command in your console after installing Scoop.

```sh
scoop install yarn
```

--------------------------------

### Install Yarn on openSUSE via RPM repository

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/opensuse.md

Use these commands to install Yarn on openSUSE from the official RPM repository. First, import the GPG key, then add the repository, and finally install Yarn with zypper.

```bash
sudo rpm --import https://dl.yarnpkg.com/rpm/pubkey.gpg
sudo zypper ar -f https://dl.yarnpkg.com/rpm/ Yarn
sudo zypper in yarn
```

--------------------------------

### Link packages and execute install scripts

Source: https://github.com/yarnpkg/website/blob/master/_posts/2017-07-11-lets-dev-a-package-manager.md

This version extends the linker to execute lifecycle scripts (preinstall, install, postinstall) after a package is installed.

```js
import cp from 'child_process';
import util from 'util';

const exec = util.promisify(cp.exec);

async function linkPackages({ name, reference, dependencies }, cwd) {
  // ... same code as before except the end:

  await Promise.all(
    dependencies.map(async ({ name, reference, dependencies }) => {
      // ... same code as before

      if (dependencyPackageJson.scripts) {
        for (let scriptName of [`preinstall`, `install`, `postinstall`]) {
          let script = dependencyPackageJson.scripts[scriptName];

          if (!script) continue;

          await exec(script, {
            cwd: target,
            env: Object.assign({}, process.env, {
              PATH: `${target}/node_modules/.bin:${process.env.PATH}`,
            }),
          });
        }
      }
    })
  );
}
```

--------------------------------

### Configure test script in package.json

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/test.md

Example package.json configuration that maps the test script to the bash file defined in the previous example.

```json
{
  "name": "my-tribute-package",
  "version": "1.0.0",
  "description":
    "This is not the best package in the world, this is just a tribute.",
  "main": "index.js",
  "author": "Yarn Contributor",
  "license": "MIT",
  "scripts": {
    "test": "scripts/test"
  }
}
```

--------------------------------

### Install nodemon globally with prefix and verify

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/global.md

Installs the nodemon package globally using the `--prefix` flag to set the install location. After installation, the `nodemon` command is available globally, as shown by `which nodemon` and running it.

```sh
$ yarn global add nodemon --prefix /usr/local
# the `nodemon` command is now available globally:
$ which nodemon
$ /usr/local/bin/nodemon
$ nodemon
```

--------------------------------

### yarn info output example

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/publishing-a-package.md

Example output of yarn info my-new-project, showing the package metadata from the npm registry.

```js
{ name: 'my-new-project',
  description: 'My New Project description.',
  'dist-tags': { latest: '1.0.0' },
  versions: [ '1.0.0' ],
  maintainers: [ { name: 'Your Name', email: 'you@example.com' } ],
  time:
  { modified: '{{ site.time | date_to_xmlschema }}',
    created: '{{ site.time | date_to_xmlschema }}',
    '1.0.0': '{{ site.time | date_to_xmlschema }}' },
  homepage: 'https://my-new-project-website.com/',
  keywords: [ 'cool', 'useful', 'stuff' ],
  repository:
   { url: 'https://example.com/your-username/my-new-project',
     type: 'git' },
  contributors:
   [ { name: 'Your Friend',
       email: 'their-email@example.com',
       url: 'http://their-website.com' },
     { name: 'Another Friend',
       email: 'another-email@example.com',
       url: 'https://another-website.org' } ],
  author: { name: 'Your Name', email: 'you@example.com' },
  bugs: { url: 'https://github.com/you/my-new-project/issues' },
  license: 'MIT',
  readmeFilename: 'README.md',
  version: '1.0.0',
  main: 'index.js',
  files: [ 'index.js', 'lib/*.js', 'bin/*.js' ],
  bin: { 'my-new-project-cli': 'bin/my-new-project-cli.js' },
  dist:
   { shasum: '908bc9a06fa4421e96ceda243c1ee1789b0dc763',
     tarball: 'https://registry.npmjs.org/my-new-project/-/my-new-project-1.0.0.tgz' },
  directories: {} }
```

--------------------------------

### package.json version field example

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/package-json.md

Example of the version field in package.json, representing the current version of the package.

```json
{
  "version": "1.0.0"
}
```

--------------------------------

### Build the website using make

Source: https://github.com/yarnpkg/website/blob/master/README.md

Use the make command to build the project.

```sh
$ make
```

--------------------------------

### Example package.json configuration

Source: https://github.com/yarnpkg/website/blob/master/_posts/2017-07-11-lets-dev-a-package-manager.md

A sample package.json file used to test the dependency tree extraction logic.

```json
{
  "name": "my-awesome-package",
  "dependencies": {
    "tar-stream": "*"
  }
}
```

--------------------------------

### yarn install --flat resolutions field example

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/install.md

Example of the resolutions field added to package.json when using yarn install --flat. This field specifies a single version for each package that is depended on at multiple version ranges.

```json
"resolutions": {
  "package-a": "2.0.0",
  "package-b": "5.0.0",
  "package-c": "1.5.2"
}
```

--------------------------------

### Serve the website on Windows

Source: https://github.com/yarnpkg/website/blob/master/README.md

Directly execute bundle and jekyll commands for environments where make is unavailable.

```sh
bundle install
bundle exec jekyll serve --incremental
```

--------------------------------

### yarn config get <key>

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/config.md

Echoes the value for a given key to stdout. Example shows getting init-license and the output BSD-2-Clause.

```sh
$ yarn config get init-license
BSD-2-Clause
```

--------------------------------

### yarn bin - print bin folder

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/bin.md

Prints the folder where yarn installs executable files for your package. Example output shows the path to the node_modules/.bin directory.

```sh
$ yarn bin
/home/emillumine/Code/Funkwhale/funkwhale/front/node_modules/.bin
```

--------------------------------

### Package.json with lifecycle scripts

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/version.md

An example of using preversion and postversion scripts to automate testing and publishing.

```json
{
  "name": "example-yarn-package",
  "version": "1.0.2",
  "description": "An example package to demonstrate Yarn",
  "scripts": {
    "test": "echo \"Running tests for version $npm_package_version...\"",
    "preversion": "yarn test",
    "postversion":
      "git push --tags && yarn publish . --tag $npm_package_version && git push && echo \"Successfully released version $npm_package_version!\""
  }
}
```

--------------------------------

### package.json with react as a dependency

Source: https://github.com/yarnpkg/website/blob/master/_posts/2018-04-18-dependencies-done-right.md

Example package.json for a React plugin that lists react as a regular dependency. This setup can lead to multiple copies of React in the dependency tree, causing issues for consumers.

```json
{
  "name": "my-awesome-plugin",
  "dependencies": {
    "react": "^16.0.0"
  }
}
```

--------------------------------

### Visual Studio Team Services Package Archive URL

Source: https://github.com/yarnpkg/website/blob/master/_posts/2017-06-16-supporting-more-registries.md

Example of the URL structure used for fetching actual tar archives from a VSTS feed, which includes a GUID instead of the feed name.

```text
// Package archive URL
https://$ACCOUNT_NAME.pkgs.visualstudio.com/_packaging/da6e033f-20ad-4ee1-a784-8995dd6836b72/npm/registry/@scope/package-name/-/package-name-0.0.1.tgz
```

--------------------------------

### Example package.json generated by yarn init

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/creating-a-project.md

Example package.json file created by yarn init. It stores project metadata including name, version, description, entry point, repository, author, and license.

```json
{
  "name": "my-new-project",
  "version": "1.0.0",
  "description": "My New Project description.",
  "main": "index.js",
  "repository": {
    "url": "https://example.com/your-username/my-new-project",
    "type": "git"
  },
  "author": "Your Name <you@example.com>",
  "license": "MIT"
}
```

--------------------------------

### CLI arguments in .yarnrc

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/yarnrc.md

Setting --<command>.<flag> <value> in .yarnrc is equivalent to running yarn <command> --<flag> <value>. The first example shows setting --install.check-files true, which is the same as running yarn install --check-files. The second example shows setting --cache-folder and the resulting output of yarn cache dir.

```shell
$> cat .yarnrc
--install.check-files true
```

```shell
$> cat .yarnrc
--cache-folder /tmp/yarn-cache/

$> yarn cache dir
/tmp/yarn-cache/v1
```

--------------------------------

### Build the project

Source: https://github.com/yarnpkg/website/blob/master/lang/en/org/contributing.md

Perform a one-off build of the project.

```sh
yarn build
```

--------------------------------

### package.json with peerDependencies for React

Source: https://github.com/yarnpkg/website/blob/master/_posts/2018-04-18-dependencies-done-right.md

Example of a package.json manifest using peerDependencies to declare React as a peer dependency. This ensures the plugin uses the same React instance as the parent package, avoiding duplication and instanceof issues. Users must add React to their own dependencies or they will get a warning.

```json
{
  "name": "my-awesome-plugin",
  "peerDependencies": {
    "react": "^16.0.0"
  }
}
```

--------------------------------

### Sample output of yarn versions

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/versions.md

Example output showing version details for Yarn, Node.js, and dependencies.

```text
yarn versions v0.24.5
{ http_parser: '2.7.0',
  node: '7.10.0',
  v8: '5.5.372.43',
  uv: '1.11.0',
  zlib: '1.2.11',
  ares: '1.10.1-DEV',
  modules: '51',
  openssl: '1.0.2k',
  icu: '58.2',
  unicode: '9.0',
  cldr: '30.0.3',
  tz: '2016j' }
✨  Done in 0.04s.
```

--------------------------------

### Install Yarn with MacPorts

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/mac.md

Installs Yarn via MacPorts. This will also install Node.js if it is not already installed.

```sh
sudo port install yarn
```

--------------------------------

### Running yarn init interactively

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/init.md

Starts an interactive session to create a package.json file in the current directory.

```sh
$ yarn init
```

```sh
question name (testdir): my-awesome-package
question version (1.0.0):
question description: The best package you will ever find.
question entry point (index.js):
question git repository: https://github.com/yarnpkg/example-yarn-package
question author: Yarn Contributor
question license (MIT):
question private:
success Saved package.json
✨  Done in 87.70s.
```

--------------------------------

### Initial package.json structure

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/version.md

The starting state of a package.json file before running the version update command.

```json
{
  "name": "example-yarn-package",
  "version": "1.0.1",
  "description": "An example package to demonstrate Yarn"
}
```

--------------------------------

### Register a package for linking

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/link.md

Example of registering a local 'react' project folder so it can be linked elsewhere.

```sh
$ cd react
$ yarn link
yarn link vx.x.x
success Registered "react".
info You can now run `yarn link "react"` in the projects where you want to use this module and it will be used instead.
```

--------------------------------

### Install Yarn without Node (nvm)

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/debian.md

Installs Yarn while skipping Node.js installation, useful when using nvm.

```sh
sudo apt update && sudo apt install --no-install-recommends yarn

```

--------------------------------

### Install Yarn via Chocolatey

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/windows.md

Run this command in your console after installing Chocolatey. It will also ensure Node.js is installed.

```sh
choco install yarn
```

--------------------------------

### Initialize .yarnclean file

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/autoclean.md

Use the --init flag to create a .yarnclean file with default entries if one does not already exist.

```bash
yarn autoclean --init
```

--------------------------------

### Example package.json dependencies

Source: https://github.com/yarnpkg/website/blob/master/_posts/2017-07-11-lets-dev-a-package-manager.md

A standard package.json structure defining dependencies with version ranges.

```json
{
    "dependencies": {
        "react": "^15.5.4",
        "babel-core": "6.25.0"
    }
}
```

--------------------------------

### Install Yarn with Homebrew

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/_installations/mac.md

Installs Yarn via the Homebrew package manager. This will also install Node.js if it is not already installed. Ensure your PATH lists nvm's shims before the Homebrew-installed Node.js if you use nvm.

```sh
brew install yarn
```

--------------------------------

### Running yarn init --yes

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/init.md

Skips the interactive session and generates a package.json using default values.

```sh
$ yarn init --yes
```

```sh
warning The yes flag has been set. This will automatically answer yes to all questions which may have security implications.
success Saved package.json
✨  Done in 0.09s.
```

--------------------------------

### Check Yarn Installation with yarn --version

Source: https://github.com/yarnpkg/website/blob/master/_layouts/pages/install.html

Run this command in your terminal to verify that Yarn is installed correctly. It outputs the installed Yarn version.

```sh
yarn --version
```

--------------------------------

### homepage field example

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/package-json.md

Sets the URL to the landing page or documentation for your package.

```json
{
  "homepage": "https://your-package.org"
}
```

--------------------------------

### Focused install with version conflict

Source: https://github.com/yarnpkg/website/blob/master/_posts/2018-05-18-focused-workspaces.md

Shows the directory layout when running a focused install with version conflicts. B is installed under A with its own nested copy of External v2, while A keeps External v1.

```text
| my_project/
|      package.json
|      node_modules/
|          A/ (symlink to packages/A)
|          B/ (symlink to packages/B)
|          External/ (v2)
|      packages/
|          A/
|              node_modules/
|                  External (v1)
|                  B/
|                      node_modules/
|                          External/ (v2)
|          B/
|              node_modules/ (empty)
```

--------------------------------

### Install Bundler

Source: https://github.com/yarnpkg/website/blob/master/README.md

Ensure Bundler is installed as a prerequisite for managing Ruby dependencies.

```sh
$ gem install bundler
```

--------------------------------

### Example Monorepo Project Structure

Source: https://github.com/yarnpkg/website/blob/master/_posts/2017-07-26-introducing-workspaces.md

A typical monorepo structure showing the root package.json and individual workspace packages.

```text
| jest/
| ---- package.json
| ---- packages/
| -------- jest-matcher-utils/
| ------------ package.json
| -------- jest-diff/
| ------------ package.json
...
```

--------------------------------

### Install published package with yarn add

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/publishing-a-package.md

Installs the published package from the npm registry.

```sh
yarn add my-new-project
```

--------------------------------

### Running yarn init --private

Source: https://github.com/yarnpkg/website/blob/master/lang/en/docs/cli/init.md

Runs the init process while automatically setting the private key to true.

```sh
$ yarn init --private
```

```sh
question name (testdir): my-awesome-package
question version (1.0.0):
question description: The best package you will ever find.
question entry point (index.js):
question git repository: https://github.com/yarnpkg/example-yarn-package
question author: Yarn Contributor
question license (MIT):
success Saved package.json
✨  Done in 87.70s.
```

```json
{
  "name": "my-awesome-package",
  "version": "1.0.0",
  "description": "The best package you will ever find.",
  "main": "index.js",
  "repository": {
    "url": "https://github.com/yarnpkg/example-yarn-package",
    "type": "git"
  },
  "author": "Yarn Contributor",
  "license": "MIT",
  "private": true
}
```
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