With output.environment.module, packaged dependency gets incorrect reference to external dependency

Bug report

What is the current behavior? I’m building a react component library, so I declare react and react-dom as externals. I’m using webpack to build our library as a module, with experiments.outputModule = true, output.environment.module = true, and output.library.type = 'module'.

I’m using a library that also declares react as an external dependency.

When I do my build:

• In the compiled code, we end up getting a reference to react as external_react_
• my code’s calls to React.createContext get compiled correctly as external_react_.createContext()
• my dependency’s calls to React.createContext get compiled incorrectly as external_react_["default"].createContext()

This results in a hard crash in consumers of my library, because external_react_["default"] is undefined and then external_react_["default"].createContext() throws.

If the current behavior is a bug, please provide the steps to reproduce.

reproduction case: https://github.com/MustafaHaddara/webpack-external-repro-case

What is the expected behavior?

My dependency’s calls to React.createContext should get compiled as external_react_.createContext()

Other relevant information: webpack version: 5.65.0 Node.js version: 14.16.0, also reproduced with 16.7.0 Operating System: Additional tools:

[MustafaHaddara]

ok, that makes sense.

thanks for your help!

[alexander-akait]

How did you import it? I realized I got the main and module keys wrong in my package.json in my repro case so you might have been importing the root index.js, I’ve updated my reproduction case now.

I tested it using https://github.com/MustafaHaddara/webpack-external-repro-case/blob/main/es/index.js, just run this in browser or using Node.js (document will be undefined)

What is webpack version in CRA? Please run npm ls webpack