Specify sourceType

[veltman]

Resolves#6163, transpile a mixture of CJS scripts and ES modules in src/ by treating only files with import or export statements as an ES module.

[Timer]

Can we put this in the Babel plugin instead, please?

[veltman]

Not sure whether there's a better place to nest this (e.g. options on a specific preset), so I put it in the main options for the preset. Feel free to move it if this isn't ideal!

[veltman]

Any thoughts on this @Timer?

[ianschmitz]

I'm wondering if this could cause regressions based on what I read in their docs: https://babeljs.io/docs/en/options#sourcetype.

Specifically:

unambiguous can be quite useful in contexts where the type is unknown, but it can lead to false matches because it's perfectly valid to have a module file that does not use import/export statements.

[mifi]

Anyone know why the travis build fails? I'm having the same problem. It's a very confusing bug because it doesn't say what's wrong with the code, it just says Attempted import error: ... is not exported from ...

In my case I had used array destructuring assignment like this:
const [x, y] = coords;
changing all instances of that into const x = coords[0]; const y = coords[1]; solved the problem, but it took me a few hours to figure out what was wrong with my code because it worked perfectly in Node.js

[veltman]

@Timer any thoughts on this? this still seems like a significant bug, I'm not sure if there's a better approach than forcing the sourceType though. Maybe there's some alternative Babel mechanism for defining the source type on a per file basis?

[danderson00]

Any progress on this? Happy to help out with some of the grunt work if it helps!

I recently upgraded react-scripts from 1.x to 3.0.1 and am now experiencing this when attempting to import a CommonJS module from an ES6 module. This worked fine before, and my understanding is that it should work? It's difficult for me to work around as I am sharing files between a react app and a nodejs app.

[yassine-be]

Is anyone on this ?
Same as @danderson00 we can't upgrade react-scripts from 1.x to 3.0.1 because of file sharing between a nodejs app and our react app.

[danderson00]

@yassine-be Though not ideal, you can work around this issue by replacing any object spread operators with Object.assign. There is a related issue - #7454.

[day-scene]

Is anyone on this ? I'd love to have this fixed.

[dmwyatt]

Yeah, this is still a problem. Any thoughts, @Timer?

[arcandio]

Just throwing my hat in on this one, hoping it's not too far out.