Bun.TranspilerOptions TypeScript interface | API Reference | Bun

Experimental

Enabled by default, use this to disable dead code elimination.

Some other transpiler options may still do some specific dead code elimination.

Replace key with value. Value must be a JSON string.

 { "process.env.NODE_ENV": "\"production\"" }

This does two things (and possibly more in the future):

JavaScript engines typically do these optimizations internally, however it might only happen much later in the compilation pipeline, after code has been executed many many times.

This will typically shrink the output size of code, but it might increase it in some cases. Do your own benchmarks!

What is the default loader used for this transpiler?

Replace an import statement with a macro.

This will remove the import statement from the final output and replace any function calls or template strings with the result returned by the macro

 {
"react-relay": {
"graphql": "bun-macro-relay"
}
}

Code that calls graphql will be replaced with the result of the macro.

import {graphql} from "react-relay";

// Input:
const query = graphql`
query {
... on User {
id
}
}
}`;

Will be replaced with:

import UserQuery from "./UserQuery.graphql";
const query = UserQuery;

Experimental

Minify whitespace and comments from the output.

Enable REPL mode transforms:

"browser"

TSConfig.json file as stringified JSON or an object Use this to set a custom JSX factory, fragment, or import source For example, if you want to use Preact instead of React. Or if you want to use Emotion.