avindra / babel-ts-export-type-bug

repro of type erase problem in babel's typescript support

This repo contains the minimum needed to demonstrate the type erasure bug seen in Babel's typescript mode.

Issues

It was seen in Recharts Issue #2360.

• Babel #12578
• Babel #11464

Reproduce

Check the checked-in es6 folder to see what babel is currently emitting, or run npm run build / yarn build locally.

Expected:

SomeType is erased from es6/index.js

Actual:

SomeType is still referenced in es6/index.js

This is a problem for all the JavaScript (non-Typescript) consumers since the type does not exist in the build.

If we check es6/ModuleA.js, we can see SomeType is erased, so it's at least partly working.