feat(loader): add functions support for locals

[yungvldai]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

I came across an interesting case in which a custom (modified) css-loader exports functions (as named exports). The current implementation uses JSON.stringify, which causes export values of type function ​​to become undefined. This small improvement will make it possible to handle function exports.

Breaking Changes

No braking changes.

Additional Info

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: yungvldai / name: Vladislav A. Ivanov (6f77727)

[alexander-akait]

Can you add test case?

[yungvldai]

Wrote unit test. I don't know how to test the integration because I didn't find a css-loader that exports functions in open-source. Probably, we can mock it 🤔

[alexander-akait]

Can we add an integration test, because unit tests are useless in most of time and don't provide real examples

[yungvldai]

Can you provide an example of how can I mock css-loader output? Did not find similar tests in repo.

[alexander-akait]

why we need mock css-loader? Also you can create small custom loader to provide example of usage, we need just check work, no need to implement all features in loader, only for test

[yungvldai]

Hello! Added tests.

[alexander-akait]

Just intresting - do you have a loader with such code generation?

[yungvldai]

Yes, I do. I have a fork of css-loader with the support of such code generation, the main idea is to parse BEM entities from classnames and generate ready-to-use functions with all possible mixes & modifiers. I'm currently working on getting this into open source.

[yungvldai]

small demo:

[codecov]

Codecov Report

Base: 90.34% // Head: 90.37% // Increases project coverage by +0.02% 🎉

Coverage data is based on head (c3dca47) compared to base (866abbe).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #985      +/-   ##
==========================================
+ Coverage   90.34%   90.37%   +0.02%     
==========================================
  Files           5        5              
  Lines         829      831       +2     
  Branches      221      222       +1     
==========================================
+ Hits          749      751       +2     
  Misses         70       70              
  Partials       10       10              

Impacted Files	Coverage Δ
src/loader.js	89.01% <100.00%> (ø)
src/utils.js	58.82% <100.00%> (+0.99%)	⬆️

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[alexander-akait]

Thank you 👍 Sorry for delay

[yungvldai]

Thank you too😊