fix: handle star import name collisions in module concatenation

[Knagis]

What kind of change does this PR introduce?

Fixes #11743

Did you add tests for your changes?

Yes

Does this PR introduce a breaking change?

No

What needs to be documented once your changes are merged?

Nothing

[webpack-bot]

For maintainers only:

• This needs to be documented (issue in webpack/webpack.js.org will be filed when merged)
• This needs to be backported to webpack 4 (issue will be created when merged)

[Knagis]

The failing pipelines seem to be related due to change of generated JS.

Not all tests run successfully on Windows, so I can't update snapshots reliably at this point.

[alexander-akait]

@Knagis What is tests not working? Do you read Contributing?

[Knagis]

@evilebottnawi

one example:

   Expected: "file:///c:/Other/Projects/webpack/test/cases/esm/import-meta/index.js"
   Received: "file:///C:/Other/Projects/webpack/test/cases/esm/import-meta/index.js"

another:

    TypeError: The "filename" argument must be of type string. Received type objectTypeError [ERR_INVALID_ARG_TYPE]: The "filename" argument must be of type string. Received type object

      145 | it("should compile", done => {
      146 |     expect(X()).toBe("X");
    > 147 |     const worker = new external_worker_threads_namespaceObject.Worker(new URL(/* worker import */ __webpack_require__.p + __webpack_require__.u(651), __webpack_require__.b));

    -       "moduleIdentifier": "<cwd>/test/fixtures/font.ttf",
    +       "moduleIdentifier": "C:/Other/Projects/webpack/test/fixtures/font.ttf",

there were few more. Most tests do run without problems.

I didn't try running under WSL yet since I am in VM where it does not work.

[alexander-akait]

@Knagis Yep, look we need some improvement for our tests, maybe you can help? I think it should be not hard, problem with C:\ and c:\

[Knagis]

I might be able, yes. I think I might have something in few days.

In the meantime for now I am updating snapshots using WSL which hopefully will enable this PR to be green

[webpack-bot]

Thank you for your pull request! The most important CI builds succeeded, we’ll review the pull request soon.

[code1x1]

0a8529f reverts the changes in ConcatenatedModule.js from 95eabe4
but im curious why this change fixes the initial bug?

[sokra]

findNewName should already return a name that avoids collisions with other variables. But the actual bug was that in some cases potential collisions were not detected. This happened in the case when ids = [], which is the case for namespace objects or the externals (which are also treated as namespace objects).

The above snippet fixes the problem.

[sokra]

Thanks