firefox: add support for firefox derivatives

[brckd]

Adds support for Firefox derivatives.

Description

Adds support for Firefox forks by introducing methods that create generic configs and options. Additional configs and options can be added in separate modules.

Most changes are just formatting. Compare them here or with git diff -w.

Browsers that can benefit from this (Reference implementations)

Browser	Changes	Resolves	Definition	Consumption
Firefox	Functionality remains unchanged.		View	View
Librewolf	Extends the existing module.	Resolves #4179, resolves #2803, closes #5004 and closes #3339.	View	View
Floorp	New Module.	Resolves #4912.	View	View
Mullvad Browser	New Module WIP. Package not yet compatible.	#4926 would be resolved if fixed.

• Change is backwards compatible.

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all or nix develop --ignore-environment .#all using Flakes.
  firefox-profile-settings already fails for me on the master branch, but other tests pass.

• Test cases updated/added. See example.
  Functionality remains the same.
  Generic tests added.

• Commit messages are formatted like

  {component}: {description}
  
  {long description}
  

  See CONTRIBUTING for more information and recent commit messages for examples.

• If this PR adds a new module

  • Added myself as module maintainer. See example.
    Wondering if I should add myself to mkFirefoxModule despite it not being a pure module.

Maintainer CC

@rycee @kira-bruneau

[brckd]

Edited the PR to contain fewer changes. Additional configs and options for other browsers are probably not scope of this PR and can be added once this is merged.

[brckd]

Derived branches Librewolf and Floorp seem to work. Will add tests for derivatives soon.

[brckd]

It would probably more elegant to keep the old module, move it to modules/programs/firefox/mkFirefoxModule.nix (or perhaps modules/lib/firefox?) and wrap it into a method that accepts config parameters.
Then just import it in modules/programs/firefox/default.nix as

let mkFirefoxModule = import ./mkFirefoxModule.nix; in {
  imports = [
    mkFirefoxModule { /** configs **/ }
    # ...
  ]
}

I'll work on the test first to finish the draft though.

[brckd]

Created the mkFirefoxModule method and added generic tests. This means the PR ticks all boxes and is ready for review! 🎉

[brckd]

Here are some things that could still be worked on:

• instead of passing configs to mkFirefoxModule, make them internal options
• move generic module factories to modules/lib

What do y'all think?

[tomodachi94]

Any hard blockers that are preventing this from being merged?

[brckd]

A maintainer needs to review it.

[rycee]

Thanks a lot! I'll had a quick look and overall everything looks great. I just added a few minor comments, and you'll also need to add yourself to maintainers.nix (and change maintainers.bricked to hm.maintainers.bricked).

[brckd]

Thanks for the review! My NixOS installation is currently broken, so it'a difficult for me to test the suggested changes, but I will make sure to try them soon.

[brckd]

Uh yea so I had like a personality crisis but I might reinstall NixOS next week and see how far I get. Sorry for letting you wait.

[brckd]

I implemented the suggested changes and waiting for the tests to finish the failed test seems to be unrelated. I will be updating the linked test branches for the derivatives to confirm that the changes were sufficient. As mentioned in #5128 (comment) there is still some refactoring that could be done, like minimizing the diff.

[brckd]

I updated the reference implementations of derivatives and how they can be used in working configs. Librewolf and Floorp work flawlessly, but Mullvad Browser's package doesn't seem to be compatible.

[kkoniuszy]

There's a small issue with your LibreWolf module, but that's not exactly the scope of this PR. The appName used in the disclaimer salt for the default search engine name is supposed to be LibreWolf, but it's set to Librewolf. This produces different hashes than the browser does and results in the default search engine setting not working for any custom engines. It works for the stock ones because Firefox skips checking the hash for those.

kkoniuszy@7752389

[brckd]

Thanks for pointing it out! I will make sure your suggestion will be part of a future PR after this one is merged. UPDATE: Your commit has also been rebased onto the reference implementation.