eslint-plugin-react/README.md

`eslint-plugin-react`
===================

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React specific linting rules for `eslint`

# Installation

Install [`eslint`](https://www.github.com/eslint/eslint) either locally or globally. (Note that locally, per project, is strongly preferred)

```sh
$ npm install eslint@7 --save-dev
```

If you installed `eslint` globally, you have to install the React plugin globally too. Otherwise, install it locally (strongly preferred)

```sh
$ npm install eslint-plugin-react --save-dev
```

# Configuration


Use [our preset](#recommended) to get reasonable defaults:

```json
  "extends": [
    "eslint:recommended",
    "plugin:react/recommended"
  ]
```

If you are using the [new JSX transform from React 17](https://reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html#removing-unused-react-imports), extend [`react/jsx-runtime`](https://github.com/yannickcr/eslint-plugin-react/blob/HEAD/index.js#L163-L176) in your eslint config (add `"plugin:react/jsx-runtime"` to `"extends"`) to disable the relevant rules.

You should also specify settings that will be shared across all the plugin rules. ([More about eslint shared settings](https://eslint.org/docs/user-guide/configuring/configuration-files#adding-shared-settings))

```json5
{
  "settings": {
    "react": {
      "createClass": "createReactClass", // Regex for Component Factory to use,
                                         // default to "createReactClass"
      "pragma": "React",  // Pragma to use, default to "React"
      "fragment": "Fragment",  // Fragment to use (may be a property of <pragma>), default to "Fragment"
      "version": "detect", // React version. "detect" automatically picks the version you have installed.
                           // You can also use `16.0`, `16.3`, etc, if you want to override the detected value.
                           // default to latest and warns if missing
                           // It will default to "detect" in the future
      "flowVersion": "0.53" // Flow version
    },
    "propWrapperFunctions": [
        // The names of any function used to wrap propTypes, e.g. `forbidExtraProps`. If this isn't set, any propTypes wrapped in a function will be skipped.
        "forbidExtraProps",
        {"property": "freeze", "object": "Object"},
        {"property": "myFavoriteWrapper"},
        // for rules that check exact prop wrappers
        {"property": "forbidExtraProps", "exact": true}
    ],
    "componentWrapperFunctions": [
        // The name of any function used to wrap components, e.g. Mobx `observer` function. If this isn't set, components wrapped by these functions will be skipped.
        "observer", // `property`
        {"property": "styled"}, // `object` is optional
        {"property": "observer", "object": "Mobx"},
        {"property": "observer", "object": "<pragma>"} // sets `object` to whatever value `settings.react.pragma` is set to
    ],
    "formComponents": [
      // Components used as alternatives to <form> for forms, eg. <Form endpoint={ url } />
      "CustomForm",
      {"name": "Form", "formAttribute": "endpoint"}
    ],
    "linkComponents": [
      // Components used as alternatives to <a> for linking, eg. <Link to={ url } />
      "Hyperlink",
      {"name": "Link", "linkAttribute": "to"}
    ]
  }
}
```

If you do not use a preset you will need to specify individual rules and add extra configuration.

Add "react" to the plugins section.

```json
{
  "plugins": [
    "react"
  ]
}
```

Enable JSX support.

With `eslint` 2+

```json
{
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": true
    }
  }
}
```

Enable the rules that you would like to use.

```json
  "rules": {
    "react/jsx-uses-react": "error",
    "react/jsx-uses-vars": "error",
  }
```

# List of supported rules

✔: Enabled in the [`recommended`](#recommended) configuration.\
🔧: Fixable with [`eslint --fix`](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems).

<!-- AUTO-GENERATED-CONTENT:START (BASIC_RULES) -->
| ✔ | 🔧 | Rule | Description |
| :---: | :---: | :--- | :--- |
|  |  | [react/boolean-prop-naming](docs/rules/boolean-prop-naming.md) | Enforces consistent naming for boolean props |
|  |  | [react/button-has-type](docs/rules/button-has-type.md) | Forbid "button" element without an explicit "type" attribute |
|  |  | [react/default-props-match-prop-types](docs/rules/default-props-match-prop-types.md) | Enforce all defaultProps are defined and not "required" in propTypes. |
|  |  | [react/destructuring-assignment](docs/rules/destructuring-assignment.md) | Enforce consistent usage of destructuring assignment of props, state, and context |
| ✔ |  | [react/display-name](docs/rules/display-name.md) | Prevent missing displayName in a React component definition |
|  |  | [react/forbid-component-props](docs/rules/forbid-component-props.md) | Forbid certain props on components |
|  |  | [react/forbid-dom-props](docs/rules/forbid-dom-props.md) | Forbid certain props on DOM Nodes |
|  |  | [react/forbid-elements](docs/rules/forbid-elements.md) | Forbid certain elements |
|  |  | [react/forbid-foreign-prop-types](docs/rules/forbid-foreign-prop-types.md) | Forbid using another component's propTypes |
|  |  | [react/forbid-prop-types](docs/rules/forbid-prop-types.md) | Forbid certain propTypes |
|  | 🔧 | [react/function-component-definition](docs/rules/function-component-definition.md) | Standardize the way function component get defined |
|  |  | [react/no-access-state-in-setstate](docs/rules/no-access-state-in-setstate.md) | Reports when this.state is accessed within setState |
|  |  | [react/no-adjacent-inline-elements](docs/rules/no-adjacent-inline-elements.md) | Prevent adjacent inline elements not separated by whitespace. |
|  |  | [react/no-array-index-key](docs/rules/no-array-index-key.md) | Prevent usage of Array index in keys |
|  | 🔧 | [react/no-arrow-function-lifecycle](docs/rules/no-arrow-function-lifecycle.md) | Lifecycle methods should be methods on the prototype, not class fields |
| ✔ |  | [react/no-children-prop](docs/rules/no-children-prop.md) | Prevent passing of children as props. |
|  |  | [react/no-danger](docs/rules/no-danger.md) | Prevent usage of dangerous JSX props |
| ✔ |  | [react/no-danger-with-children](docs/rules/no-danger-with-children.md) | Report when a DOM element is using both children and dangerouslySetInnerHTML |
| ✔ |  | [react/no-deprecated](docs/rules/no-deprecated.md) | Prevent usage of deprecated methods |
|  |  | [react/no-did-mount-set-state](docs/rules/no-did-mount-set-state.md) | Prevent usage of setState in componentDidMount |
|  |  | [react/no-did-update-set-state](docs/rules/no-did-update-set-state.md) | Prevent usage of setState in componentDidUpdate |
| ✔ |  | [react/no-direct-mutation-state](docs/rules/no-direct-mutation-state.md) | Prevent direct mutation of this.state |
| ✔ |  | [react/no-find-dom-node](docs/rules/no-find-dom-node.md) | Prevent usage of findDOMNode |
|  | 🔧 | [react/no-invalid-html-attribute](docs/rules/no-invalid-html-attribute.md) | Forbid attribute with an invalid values` |
| ✔ |  | [react/no-is-mounted](docs/rules/no-is-mounted.md) | Prevent usage of isMounted |
|  |  | [react/no-multi-comp](docs/rules/no-multi-comp.md) | Prevent multiple component definition per file |
|  |  | [react/no-namespace](docs/rules/no-namespace.md) | Enforce that namespaces are not used in React elements |
|  |  | [react/no-redundant-should-component-update](docs/rules/no-redundant-should-component-update.md) | Flag shouldComponentUpdate when extending PureComponent |
| ✔ |  | [react/no-render-return-value](docs/rules/no-render-return-value.md) | Prevent usage of the return value of React.render |
|  |  | [react/no-set-state](docs/rules/no-set-state.md) | Prevent usage of setState |
| ✔ |  | [react/no-string-refs](docs/rules/no-string-refs.md) | Prevent string definitions for references and prevent referencing this.refs |
|  |  | [react/no-this-in-sfc](docs/rules/no-this-in-sfc.md) | Report "this" being used in stateless components |
|  |  | [react/no-typos](docs/rules/no-typos.md) | Prevent common typos |
| ✔ |  | [react/no-unescaped-entities](docs/rules/no-unescaped-entities.md) | Detect unescaped HTML entities, which might represent malformed tags |
| ✔ | 🔧 | [react/no-unknown-property](docs/rules/no-unknown-property.md) | Prevent usage of unknown DOM property |
|  |  | [react/no-unsafe](docs/rules/no-unsafe.md) | Prevent usage of unsafe lifecycle methods |
|  |  | [react/no-unstable-nested-components](docs/rules/no-unstable-nested-components.md) | Prevent creating unstable components inside components |
|  |  | [react/no-unused-class-component-methods](docs/rules/no-unused-class-component-methods.md) | Prevent declaring unused methods of component class |
|  |  | [react/no-unused-prop-types](docs/rules/no-unused-prop-types.md) | Prevent definitions of unused prop types |
|  |  | [react/no-unused-state](docs/rules/no-unused-state.md) | Prevent definition of unused state fields |
|  |  | [react/no-will-update-set-state](docs/rules/no-will-update-set-state.md) | Prevent usage of setState in componentWillUpdate |
|  |  | [react/prefer-es6-class](docs/rules/prefer-es6-class.md) | Enforce ES5 or ES6 class for React Components |
|  |  | [react/prefer-exact-props](docs/rules/prefer-exact-props.md) | Prefer exact proptype definitions |
|  | 🔧 | [react/prefer-read-only-props](docs/rules/prefer-read-only-props.md) | Require read-only props. |
|  |  | [react/prefer-stateless-function](docs/rules/prefer-stateless-function.md) | Enforce stateless components to be written as a pure function |
| ✔ |  | [react/prop-types](docs/rules/prop-types.md) | Prevent missing props validation in a React component definition |
| ✔ |  | [react/react-in-jsx-scope](docs/rules/react-in-jsx-scope.md) | Prevent missing React when using JSX |
|  |  | [react/require-default-props](docs/rules/require-default-props.md) | Enforce a defaultProps definition for every prop that is not a required prop. |
|  |  | [react/require-optimization](docs/rules/require-optimization.md) | Enforce React components to have a shouldComponentUpdate method |
| ✔ |  | [react/require-render-return](docs/rules/require-render-return.md) | Enforce ES5 or ES6 class for returning value in render function |
|  | 🔧 | [react/self-closing-comp](docs/rules/self-closing-comp.md) | Prevent extra closing tags for components without children |
|  |  | [react/sort-comp](docs/rules/sort-comp.md) | Enforce component methods order |
|  |  | [react/sort-prop-types](docs/rules/sort-prop-types.md) | Enforce propTypes declarations alphabetical sorting |
|  |  | [react/state-in-constructor](docs/rules/state-in-constructor.md) | State initialization in an ES6 class component should be in a constructor |
|  |  | [react/static-property-placement](docs/rules/static-property-placement.md) | Defines where React component static properties should be positioned. |
|  |  | [react/style-prop-object](docs/rules/style-prop-object.md) | Enforce style prop value is an object |
|  |  | [react/void-dom-elements-no-children](docs/rules/void-dom-elements-no-children.md) | Prevent passing of children to void DOM elements (e.g. `<br />`). |
<!-- AUTO-GENERATED-CONTENT:END -->

## JSX-specific rules

<!-- AUTO-GENERATED-CONTENT:START (JSX_RULES) -->
| ✔ | 🔧 | Rule | Description |
| :---: | :---: | :--- | :--- |
|  | 🔧 | [react/jsx-boolean-value](docs/rules/jsx-boolean-value.md) | Enforce boolean attributes notation in JSX |
|  |  | [react/jsx-child-element-spacing](docs/rules/jsx-child-element-spacing.md) | Ensures inline tags are not rendered without spaces between them |
|  | 🔧 | [react/jsx-closing-bracket-location](docs/rules/jsx-closing-bracket-location.md) | Validate closing bracket location in JSX |
|  | 🔧 | [react/jsx-closing-tag-location](docs/rules/jsx-closing-tag-location.md) | Validate closing tag location for multiline JSX |
|  | 🔧 | [react/jsx-curly-brace-presence](docs/rules/jsx-curly-brace-presence.md) | Disallow unnecessary JSX expressions when literals alone are sufficient or enfore JSX expressions on literals in JSX children or attributes |
|  | 🔧 | [react/jsx-curly-newline](docs/rules/jsx-curly-newline.md) | Enforce consistent line breaks inside jsx curly |
|  | 🔧 | [react/jsx-curly-spacing](docs/rules/jsx-curly-spacing.md) | Enforce or disallow spaces inside of curly braces in JSX attributes |
|  | 🔧 | [react/jsx-equals-spacing](docs/rules/jsx-equals-spacing.md) | Disallow or enforce spaces around equal signs in JSX attributes |
|  |  | [react/jsx-filename-extension](docs/rules/jsx-filename-extension.md) | Restrict file extensions that may contain JSX |
|  | 🔧 | [react/jsx-first-prop-new-line](docs/rules/jsx-first-prop-new-line.md) | Ensure proper position of the first property in JSX |
|  | 🔧 | [react/jsx-fragments](docs/rules/jsx-fragments.md) | Enforce shorthand or standard form for React fragments |
|  |  | [react/jsx-handler-names](docs/rules/jsx-handler-names.md) | Enforce event handler naming conventions in JSX |
|  | 🔧 | [react/jsx-indent](docs/rules/jsx-indent.md) | Validate JSX indentation |
|  | 🔧 | [react/jsx-indent-props](docs/rules/jsx-indent-props.md) | Validate props indentation in JSX |
| ✔ |  | [react/jsx-key](docs/rules/jsx-key.md) | Report missing `key` props in iterators/collection literals |
|  |  | [react/jsx-max-depth](docs/rules/jsx-max-depth.md) | Validate JSX maximum depth |
|  | 🔧 | [react/jsx-max-props-per-line](docs/rules/jsx-max-props-per-line.md) | Limit maximum of props on a single line in JSX |
|  | 🔧 | [react/jsx-newline](docs/rules/jsx-newline.md) | Require or prevent a new line after jsx elements and expressions. |
|  |  | [react/jsx-no-bind](docs/rules/jsx-no-bind.md) | Prevents usage of Function.prototype.bind and arrow functions in React component props |
| ✔ |  | [react/jsx-no-comment-textnodes](docs/rules/jsx-no-comment-textnodes.md) | Comments inside children section of tag should be placed inside braces |
|  |  | [react/jsx-no-constructed-context-values](docs/rules/jsx-no-constructed-context-values.md) | Prevents JSX context provider values from taking values that will cause needless rerenders. |
| ✔ |  | [react/jsx-no-duplicate-props](docs/rules/jsx-no-duplicate-props.md) | Enforce no duplicate props |
|  |  | [react/jsx-no-literals](docs/rules/jsx-no-literals.md) | Prevent using string literals in React component definition |
|  |  | [react/jsx-no-script-url](docs/rules/jsx-no-script-url.md) | Forbid `javascript:` URLs |
| ✔ | 🔧 | [react/jsx-no-target-blank](docs/rules/jsx-no-target-blank.md) | Forbid `target="_blank"` attribute without `rel="noreferrer"` |
| ✔ |  | [react/jsx-no-undef](docs/rules/jsx-no-undef.md) | Disallow undeclared variables in JSX |
|  | 🔧 | [react/jsx-no-useless-fragment](docs/rules/jsx-no-useless-fragment.md) | Disallow unnecessary fragments |
|  | 🔧 | [react/jsx-one-expression-per-line](docs/rules/jsx-one-expression-per-line.md) | Limit to one expression per line in JSX |
|  |  | [react/jsx-pascal-case](docs/rules/jsx-pascal-case.md) | Enforce PascalCase for user-defined JSX components |
|  | 🔧 | [react/jsx-props-no-multi-spaces](docs/rules/jsx-props-no-multi-spaces.md) | Disallow multiple spaces between inline JSX props |
|  |  | [react/jsx-props-no-spreading](docs/rules/jsx-props-no-spreading.md) | Prevent JSX prop spreading |
|  |  | [react/jsx-sort-default-props](docs/rules/jsx-sort-default-props.md) | Enforce default props alphabetical sorting |
|  | 🔧 | [react/jsx-sort-props](docs/rules/jsx-sort-props.md) | Enforce props alphabetical sorting |
|  | 🔧 | [react/jsx-space-before-closing](docs/rules/jsx-space-before-closing.md) | Validate spacing before closing bracket in JSX |
|  | 🔧 | [react/jsx-tag-spacing](docs/rules/jsx-tag-spacing.md) | Validate whitespace in and around the JSX opening and closing brackets |
| ✔ |  | [react/jsx-uses-react](docs/rules/jsx-uses-react.md) | Prevent React to be marked as unused |
| ✔ |  | [react/jsx-uses-vars](docs/rules/jsx-uses-vars.md) | Prevent variables used in JSX to be marked as unused |
|  | 🔧 | [react/jsx-wrap-multilines](docs/rules/jsx-wrap-multilines.md) | Prevent missing parentheses around multilines JSX |
<!-- AUTO-GENERATED-CONTENT:END -->

## Other useful plugins

- Rules of Hooks: [eslint-plugin-react-hooks](https://github.com/facebook/react/tree/master/packages/eslint-plugin-react-hooks)
- JSX accessibility: [eslint-plugin-jsx-a11y](https://github.com/evcohen/eslint-plugin-jsx-a11y)
- React Native: [eslint-plugin-react-native](https://github.com/Intellicode/eslint-plugin-react-native)

# Shareable configurations

## Recommended

This plugin exports a `recommended` configuration that enforces React good practices.

To enable this configuration use the `extends` property in your `.eslintrc` config file:

```json
{
  "extends": ["eslint:recommended", "plugin:react/recommended"]
}
```

See [`eslint` documentation](https://eslint.org/docs/user-guide/configuring/configuration-files#extending-configuration-files) for more information about extending configuration files.

## All

This plugin also exports an `all` configuration that includes every available rule.
This pairs well with the `eslint:all` rule.

```json
{
  "plugins": [
    "react"
  ],
  "extends": ["eslint:all", "plugin:react/all"]
}
```

**Note**: These configurations will import `eslint-plugin-react` and enable JSX in [parser options](http://eslint.org/docs/user-guide/configuring#specifying-parser-options).

# License

`eslint-plugin-react` is licensed under the [MIT License](http://www.opensource.org/licenses/mit-license.php).


[npm-url]: https://npmjs.org/package/eslint-plugin-react
[npm-image]: https://img.shields.io/npm/v/eslint-plugin-react.svg

[travis-url]: https://travis-ci.org/yannickcr/eslint-plugin-react
[travis-image]: https://img.shields.io/travis/yannickcr/eslint-plugin-react/master.svg

[deps-url]: https://david-dm.org/yannickcr/eslint-plugin-react
[deps-image]: https://img.shields.io/david/dev/yannickcr/eslint-plugin-react.svg

[climate-url]: https://codeclimate.com/github/yannickcr/eslint-plugin-react
[climate-image]: https://img.shields.io/codeclimate/maintainability/yannickcr/eslint-plugin-react.svg

[status-url]: https://github.com/yannickcr/eslint-plugin-react/pulse
[status-image]: https://img.shields.io/github/last-commit/yannickcr/eslint-plugin-react.svg

[tidelift-url]: https://tidelift.com/subscription/pkg/npm-eslint-plugin-react?utm_source=npm-eslint-plugin-react&utm_medium=referral&utm_campaign=readme
[tidelift-image]: https://tidelift.com/badges/github/yannickcr/eslint-plugin-react?style=flat