eslint-plugin-prettier

What is eslint-plugin-prettier?

The eslint-plugin-prettier npm package integrates Prettier, an opinionated code formatter, with ESLint, a tool for identifying and reporting on patterns in JavaScript. It allows you to use Prettier as an ESLint rule and reports differences as individual ESLint issues.

What are eslint-plugin-prettier's main functionalities?

Code Formatting

Automatically format code to match the style specified in your Prettier configuration when you run ESLint with the --fix option.

"scripts": { "lint": "eslint --fix 'src/**/*.js'" }

Integration with ESLint Rules

Use Prettier to enforce a consistent code style while still using ESLint to catch possible errors.

{ "extends": ["plugin:prettier/recommended"] }

Customizable Formatting Rules

Override default Prettier options to tailor the formatting to your project's needs.

{ "rules": { "prettier/prettier": ["error", { "singleQuote": true, "parser": "flow" }] } }

Other packages similar to eslint-plugin-prettier

eslint-config-prettier

Turns off all ESLint rules that are unnecessary or might conflict with Prettier. It's used to avoid conflicts between ESLint and Prettier formatting rules.

prettier-eslint

Formats your JavaScript using Prettier followed by ESLint --fix. It's similar to eslint-plugin-prettier but applies Prettier formatting first and then runs ESLint's auto-fixing feature.

stylelint-prettier

Runs Prettier as a Stylelint rule and reports differences as individual Stylelint issues. It's similar to eslint-plugin-prettier but for stylesheets and integrates with Stylelint instead of ESLint.

tslint-config-prettier

Disables TSLint formatting rules that might conflict with Prettier. It's similar to eslint-config-prettier but for TypeScript projects using TSLint instead of ESLint.

README

eslint-plugin-prettier

Runs Prettier as an ESLint rule and reports differences as individual ESLint issues.

Sample

error: Insert `,` (prettier/prettier) at pkg/commons-atom/ActiveEditorRegistry.js:22:25:
  20 | import {
  21 |   observeActiveEditorsDebounced,
> 22 |   editorChangesDebounced
     |                         ^
  23 | } from './debounced';;
  24 |
  25 | import {observableFromSubscribeFunction} from '../commons-node/event';


error: Delete `;` (prettier/prettier) at pkg/commons-atom/ActiveEditorRegistry.js:23:21:
  21 |   observeActiveEditorsDebounced,
  22 |   editorChangesDebounced
> 23 | } from './debounced';;
     |                     ^
  24 |
  25 | import {observableFromSubscribeFunction} from '../commons-node/event';
  26 | import {cacheWhileSubscribed} from '../commons-node/observable';


2 errors found.

./node_modules/.bin/eslint --format codeframe pkg/commons-atom/ActiveEditorRegistry.js (code from nuclide).

Installation

npm install --save-dev eslint-plugin-prettier
npm install --save-dev --save-exact prettier

eslint-plugin-prettier does not install Prettier or ESLint for you. You must install these yourself.

Then, in your .eslintrc.json:

{
  "plugins": [
    "prettier"
  ],
  "rules": {
    "prettier/prettier": "error"
  }
}

Recommended Configuration

This plugin works best if you disable all other ESLint rules relating to code formatting, and only enable rules that detect patterns in the AST. (If another active ESLint rule disagrees with prettier about how code should be formatted, it will be impossible to avoid lint errors.) You can use eslint-config-prettier to disable all formatting-related ESLint rules.

If your desired formatting does not match the prettier output, you should use a different tool such as prettier-eslint instead.

To integrate this plugin with eslint-config-prettier, you can use the "recommended" configuration:

1. In addition to the above installation instructions, install eslint-config-prettier:

npm install --save-dev eslint-config-prettier

1. Then you need to add plugin:prettier/recommended as the last extension in your .eslintrc.json:

{
  "extends": [
    "plugin:prettier/recommended"
  ]
}

This does three things:

• Enables eslint-plugin-prettier.
• Sets the prettier/prettier rule to "error".
• Extends the eslint-config-prettier configuration.

You can then set Prettier's own options inside a .prettierrc file.

1. In order to support special ESLint plugins (e.g. eslint-plugin-react), add extra exclusions for the plugins you use like so:

{
  "extends": [
    "plugin:prettier/recommended",
    "prettier/flowtype",
    "prettier/react",
    "prettier/standard"
  ]
}

For the list of every available exclusion rule set, please see the readme of eslint-config-prettier.

Options

Note: While it is possible to pass options to Prettier via your ESLint configuration file, it is not recommended because editor extensions such as prettier-atom and prettier-vscode will read .prettierrc, but won't read settings from ESLint, which can lead to an inconsistent experience.

• The first option:

  • Objects are passed directly to Prettier as options. Example:

    "prettier/prettier": ["error", {"singleQuote": true, "parser": "flow"}]
    

  • Or the string "fb" may be used to set "Facebook style" defaults:

    "prettier/prettier": ["error", "fb"]
    

    Equivalent to:

    "prettier/prettier": ["error", {
      "singleQuote": true,
      "trailingComma": "all",
      "bracketSpacing": false,
      "jsxBracketSameLine": true,
      "parser": "flow"
    }]
    

  NB: This option will merge and override any config set with .prettierrc files (for Prettier < 1.7.0, config files are ignored)

• The second option:

  • A string with a pragma that triggers this rule. By default, this rule applies to all files. However, if you set a pragma (this option), only files with that pragma in the heading docblock will be checked. All pragmas must start with @. Example:

    "prettier/prettier": ["error", null, "@prettier"]
    

    Only files with @prettier in the heading docblock will be checked:

    /** @prettier */
    
    console.log(1 + 2 + 3);
    

    Or:

    /**
     * @prettier
     */
    
    console.log(4 + 5 + 6);
    

    This option is useful if you're migrating a large codebase and already use pragmas like @flow.

  • An object with the following options

    • pragma: Also sets the aforementioned pragma: a string with a pragma that triggers this rule. By default, this rule applies to all files. However, if you set a pragma (this option), only files with that pragma in the heading docblock will be checked. All pragmas must start with @.

      "prettier/prettier": ["error", null, {
        "pragma": "@prettier"
      }]
      

    • usePrettierrc: Enables loading of the Prettier configuration file, (default: true). May be useful if you are using multiple tools that conflict with each other, or do not wish to mix your ESLint settings with your Prettier configuration.

      "prettier/prettier": ["error", null, {
        "usePrettierrc": false
      }]
      

• The rule is autofixable -- if you run eslint with the --fix flag, your code will be formatted according to prettier style.

---

Contributing

See CONTRIBUTING.md

Changelog

v2.7.0 (2018-09-26)

• Update: Support prettierignore and custom processors (#111) (38537ba)
• Build: switch to release script package (047dc8f)