yarn.md

   1 ---
   2 title: Yarn
   3 category: JavaScript libraries
   4 layout: 2017/sheet
   5 weight: -3
   6 updated: 2019-09-30
   7 prism_languages: [json, bash]
   8 tags: [Featurable]
   9 ---
  10
  11 ### npm equivalents
  12
  13 | npm | yarn |
  14 | --- | ---- |
  15 | `npm init` | `yarn init` |
  16 | `npm install` | `yarn` |
  17 | `npm install gulp --save` | `yarn add gulp` |
  18 | `npm install gulp --save-dev --save-exact` | `yarn add gulp --dev --exact` |
  19 | `npm install -g gulp` | `yarn global add gulp` |
  20 | `npm update` | `yarn upgrade` |
  21 | `./node_modules/.bin/gulp` | `yarn run gulp` |
  22 {: .-left-align.-headers}
  23
  24 ### yarn install
  25
  26 ```
  27 --no-lockfile
  28 --pure-lockfile
  29 --frozen-lockfile
  30 --silent
  31 --offline
  32 --update-checksums
  33 --check-files
  34 --flat
  35 --force
  36 --ignore-scripts
  37 --modules-folder <path>
  38 --production[=true|false]
  39 ```
  40
  41 These options are available for `yarn install`.
  42
  43 ### yarn add
  44
  45 ```
  46 --dev
  47 --peer
  48 --optional
  49 --exact
  50 --tilde
  51 ```
  52
  53 These options are available for `yarn add`.
  54
  55 ### Workspaces
  56
  57 In `package.json`:
  58 {: .-setup}
  59
  60 ```json
  61 "workspaces": [
  62   "packages/*"
  63 ]
  64 ```
  65
  66 ```
  67 jest/
  68 ├─ package.json
  69 └─ packages/
  70    ├─ jest-matcher-utils/
  71    │  └─ package.json
  72    └─ jest-diff/
  73       └─ package.json
  74 ```
  75 {: .-box-chars}
  76
  77 (New in 1.0) Allows monorepos to share packages with each other. See: [Introducing workspaces](https://yarnpkg.com/blog/2017/08/02/introducing-workspaces/)
  78
  79 ### Selective version resolution
  80
  81 In `package.json`:
  82 {: .-setup}
  83
  84 ```json
  85 "resolutions": {
  86   "**/sass-brunch/node-sass": "4.5.2"
  87 }
  88 ```
  89
  90 (New in 1.0) Allows you to specify versions for sub-dependencies. See: [Selective version resolutions](https://github.com/yarnpkg/yarn/pull/4105)
  91
  92 ### Create
  93
  94 ```bash
  95 yarn create react-app hello
  96 ```
  97
  98 Install `create-react-app` and runs it. See: [yarn create](https://github.com/yarnpkg/rfcs/blob/master/implemented/0000-yarn-create.md)