Moti Zilberman

Where is the bad source location coming from? This kinda looks like it masks a genuine bug elsewhere. Do you have repro steps? Also, we have [tests](https://github.com/facebook/metro/commit/a398f34a34a9b385af6c2bd64ea3ad161913b067) for this code...

Seems related to https://babeljs.io/docs/en/babel-plugin-transform-flow-strip-types#allowdeclarefields - the Babel docs say this will become the default in Babel 8, and IIRC I've advocated for not changing the default in Metro before Babel...

@robhogan @jacdebug We should add this (changing the default allowDeclareFields setting) to the list of breaking changes planned for inclusion in the new transformer.

Hey @bcye! I think for the time being this type of feature fits best in the React Native CLI (or the Expo CLI, depends on what you're using) which wraps...

This looks great! Re: `.native.native`, that seems weird - is it just an artifact of the current tests or does it show up in real-world usage too?

Oh, found the `.native` bug: https://github.com/facebook/metro/blob/c39b51b2df74479abd00b30866e06c35d7a23385/packages/metro-resolver/src/resolve.js#L463-L464 We need to check that `sourceExt` isn't empty.

Thanks @robrechtme! This is a known issue. `experimentalImportSupport: true` solves this, but the option is currently undocumented and experimental (as reflected in its name). We're looking into what it would...

@robrechtme (and @bitcrumb): Is there a `babel.config.js` file in your project? One quirk of the current implementation of `experimentalImportSupport: true` is that it depends on disabling Babel's ES Module support,...

UPDATE: This is now described as a design choice in the main comment: https://github.com/facebook/flow/pull/6727#user-content-forbid-empty-string --- In light of the issue outlined in https://github.com/facebook/react/issues/13400, I'm currently thinking of removing `""` as...

@mrkev: > It might be helpful to do this work throughout multiple PRs, and keep track of progress in a "master issue? Yes in principle, I'm just trying to get...