Error when babel.config.js is ESM _and_ in the same directory as where rollup is executed from.

[NullVoxPopuli]

• Version: 2.0.5
• Rollup Version: 2.66.0
• Operating System and version (if applicable): Linux/Ubuntu 20.04
• Node Version (if applicable): 16.13.1
• Does it work with tsc (if applicable): yes

Reproduction

1. define babel.config.js as ESM in a package with type="module" (this step is optional)
2. define rollup config:

   import babelConfig from './babel.config';
   
     ts({
       transpiler: 'babel',
       browserslist: false,
       babelConfig, // set here
     }),

3. run rollup -c
4. observe error:

   Error while loading config - You appear to be using a native ECMAScript module configuration file, which is only supported when running Babel asynchronously.
   

Expected Behavior

No error

Actual Behavior

Error.

What's funny is if I move the babel.config to a different directory, (like config or something), the error goes away.

So it seems that even though I'm setting babelConfig, the ts plugin is still trying to read babel.config.js itself

[wessberg]

Hey there. Thanks for making me aware of this. I've added support for ESM-based Babel configs in v3.0.2