react/react-in-jsx-scope

With the classic JSX transform, <App /> compiles to React.createElement(App). If the file doesn't import React, that line throws ReferenceError: React is not defined when it runs.

If the file has a @jsx comment, or you set settings.react.pragma ([lint.settings.react] in bunfig.toml, or settings in an ESLint config), the rule looks for that name instead of React.

Configure#

Off by default. To turn it on:

[lint.rules]
"react/react-in-jsx-scope" = "error" # or "warn"

Examples#

Reported:

export function App() {
  return <h1>Hello</h1>;
}

Not reported:

import React from "react";

export function App() {
  return <h1>Hello</h1>;
}

/** @jsx h */
import { h } from "preact";

export function App() {
  return <h1>Hello</h1>;
}

When not to use it#

Turn it off if you use the automatic JSX transform ("jsx": "react-jsx" in tsconfig.json), which is what Bun does by default. That transform imports what it needs by itself, so React doesn't need to be in scope.