# Source: https://github.com/jsx-eslint/eslint-plugin-react/blob/master/docs/rules/react-in-jsx-scope.md

# Disallow missing React when using JSX (`react/react-in-jsx-scope`)

💼🚫 This rule is enabled in the ☑️ `recommended` [config](https://github.com/jsx-eslint/eslint-plugin-react/#shareable-configs). This rule is _disabled_ in the 🏃 `jsx-runtime` [config](https://github.com/jsx-eslint/eslint-plugin-react/#shareable-configs).

<!-- end auto-generated rule header -->

When using JSX, `<a />` expands to `React.createElement("a")`. Therefore the `React` variable must be in scope.

If you are using the @jsx pragma this rule will check the designated variable and not the `React` one.

## Rule Details

Examples of **incorrect** code for this rule:

```jsx
var Hello = <div>Hello {this.props.name}</div>;
```

```jsx
/** @jsx Foo.bar */
var React = require('react');

var Hello = <div>Hello {this.props.name}</div>;
```

Examples of **correct** code for this rule:

```jsx
import React from 'react';

var Hello = <div>Hello {this.props.name}</div>;
```

```jsx
var React = require('react');

var Hello = <div>Hello {this.props.name}</div>;
```

```jsx
/** @jsx Foo.bar */
var Foo = require('foo');

var Hello = <div>Hello {this.props.name}</div>;
```

## When Not To Use It

If you are not using JSX, or if you are setting `React` as a global variable.

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), you should disable this rule by extending [`react/jsx-runtime`](https://github.com/jsx-eslint/eslint-plugin-react/blob/8cf47a8ac2242ee00ea36eac4b6ae51956ba4411/index.js#L165-L179) in your eslint config (add `"plugin:react/jsx-runtime"` to `"extends"`).