React compiler healthcheck (and ESLint plugin) ignores all files if a babel.config.js file is present

[guillaumebrunerie]

Summary

Create the following two files in a new directory:

// index.jsx
const App = () => <div />;

// babel.config.js
export default {};

Then run npx react-compiler-healthcheck --src index.jsx. It reports Successfully compiled 0 out of 0 components.

Then remove the babel.config.js file (or comment out the line inside it) and run npx react-compiler-healthcheck --src index.jsx again. It now reports Successfully compiled 1 out of 1 components., as expected.

[guillaumebrunerie]

In my real codebase it is not enough to comment out the contents of babel.config.js, I need to remove it entirely (or rename it).

With it I get Successfully compiled 0 out of 0 components. and without it I get Successfully compiled 370 out of 406 components.

[guillaumebrunerie]

This affects the ESLint plugin as well, with a babel.config.js it silently doesn’t report any errors, and removing it makes the ESLint plugin work.

[poteto]

Thanks for reporting. Could you share a repro app please?

[guillaumebrunerie]

@poteto The OP contains a minimal repro, which I assumed would be enough to investigate the problem. Or do you need an actual working app?

[poteto]

an actual app would be ideal, there are many variables when it comes to builds so it'd help us figure this out more easily. fwiw I've run the healthcheck script on a few repos with babel configs

[guillaumebrunerie]

I can reproduce it on an empty Vite app, if that helps? Although my original codebase (not open source) is a Webpack app.

$ npm create vite@latest bug-babel-config -- --template react
$ cd bug-babel-config
$ npx react-compiler-healthcheck
Successfully compiled 1 out of 1 components.
StrictMode usage found.
Found no usage of incompatible libraries
$ touch babel.config.js
$ npx react-compiler-healthcheck
Successfully compiled 0 out of 0 components.
StrictMode usage found.
Found no usage of incompatible libraries.

[guillaumebrunerie]

Here is a real project of mine with the same issue: https://github.com/guillaumebrunerie/LD55.

[poteto]

I'll look into it, I think this is something to do with the eslint plugin picking up your config, and since it's empty, it doesn't run the compiler