test: usage with css-loader and composes

[avaly]

What kind of change does this PR introduce?
Test cases: passing and failing

Did you add tests for your changes?
Yes, only tests.

Summary
Using style-loader and css-loader with local scoped identifiers and composes works as expected.

However when adding css-loaders getLocalIdent option, only some identifiers are properly passed through the custom getLocalIdent, while the identifiers from the composed files are still using the localIdentName option.

See the failing test local scope, composing, custom getLocalIdent

I submitted this PR here, because this is not reproducible when using only the css-loader.

[jsf-clabot]

All committers have signed the CLA.

[michael-ciniawsky]

@avaly Sry for the delay based on your description this sounds like a bug in css-loader instead?

[michael-ciniawsky]

The CI is also failing but it seems this is intentional for demonstration?

[avaly]

@michael-ciniawsky I'm not sure where the issue is between style-loader and css-loader. What's interesting is I can't reproduce this bug using only css-loader, only when throwing style-loader in the mix. I suspect it might be from how the options of css-loader are being handled by webpack when chaining the two loaders, since the getLocalIdent is a function, but not sure.

[avaly]

@michael-ciniawsky Sorry for opening the PR here, but I tried adding this type of failing tests for the css-loader repo, but I could not replicate the bug. I will open a bug in that repo to make this visible there as well.

[michael-ciniawsky]

I also need to take a deeper look at it first aswell 😛, yep please open an issue in css-loader so i can keep track of that

Is this PR for demonstration purposes only or subject to eventually merge in the future ? 🙃

[avaly]

I was looking into the css-loader issues now, and I found webpack-contrib/css-loader#389. It seems that the solution you suggested there (adding an ident) fixes this issue.

I've updated my branch and tests seem to pass. Feel free to merge it or not, though I feel it might be helpful for others who might run into this.