Bun supports .jsx and .tsx files out of the box. Bun's internal transpiler converts JSX syntax into vanilla JavaScript before execution.
react.tsx
function Component(props: {message: string}) {
return (
<body>
<h1 style={{color: 'red'}}>{props.message}</h1>
</body>
);
}
console.log(<Component message="Hello world!" />);
Bun implements special logging for JSX to make debugging easier.
bun run react.tsx<Component message="Hello world!" />Prop punning
The Bun runtime also supports "prop punning for JSX. This is a shorthand syntax useful for assigning a variable to a prop with the same name.
function Div(props: {className: string;}) {
const {className} = props;
// without punning
return <div className={className} />;
// with punning
return <div {className} />;
}
Server-side rendering
To server-side render (SSR) React in an HTTP server:
ssr.tsx
import {renderToReadableStream} from 'react-dom/server';
function Component(props: {message: string}) {
return (
<body>
<h1 style={{color: 'red'}}>{props.message}</h1>
</body>
);
}
Bun.serve({
port: 4000,
async fetch() {
const stream = await renderToReadableStream(
<Component message="Hello from server!" />
);
return new Response(stream, {
headers: {'Content-Type': 'text/html'},
});
},
});