Modify babel config as part of our plugin on file base

[fkrauthan]

I have a somewhat unique problem. I want to transpile a bunch of files through babel. My problem is: Depending on the first comment header I need different targets (e.g. some files might be targeting the browser and some targeting node). Is there any way to write a plugin that gets invoked first. For example, do a simple string contains check to see what type of file it is and then modify the targets or do I have to try to cover everything based on include and exclude patterns and based on filenames? Or is there maybe even a third option?

[JLHwung]

A plugin could manipulate Babel options by manipulateOptions(), but it could do so only at the config resolving phase. At the time when Babel is processing the input source, the config can no longer be mutated.

cover everything based on include and exclude patterns and based on filenames

Yes. And you can read all sources, check certain strings, and programmatically generate input and exclude for babel.config.js.

[fkrauthan]

Ok so pretty much my only option is calling babel multiple times with different input, exclude settings. Or is there a way to have overwrite settings (similar to what eslint offers) to change settings for a couple of files but not all of them?

[JLHwung]

You can use the overrides option.

[fkrauthan]

Oh nice so I could combine overrides with input, exclude rules to have a single babel config and a single babel cli command to apply different targets for example? That's pretty cool thank you/