progs: firefox: *.userChrome may be path or drv

[spikespaz]

Description

This allows programs.firefox.profiles.*.userChrome to be set to a:
derivation, path/path-like string to directory or file, or multiline
text to be used as content verbatim.

This allows setting, for example(s):

programs.firefox.profiles."jacob.default".userChrome = pkgs.wavefox;
programs.firefox.profiles."jacob.default".userChrome =
    "${pkgs.wavefox}/userChrome.css";

Checklist

• (Painstakingly) Change is backwards compatible.

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all
  or nix build --reference-lock-file flake.lock ./tests#test-all using Flakes.

• Test cases updated/added. See example.

• 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.

Maintainer CC

[spikespaz]

Removed accidental VS Code workspace change. Should be good now.

[khaneliman]

Thanks, this actually allows me to remove some hacky stuff I had to do with my configuration for installing a theme.

[antonmosich]

This broke my config, in which I set

programs.firefox.profiles.<name>.userChrome = ''
<css>
'';

The error says that the string doesn't represent an absolute path.

It seems to fail while executing lib.pathIsDirectory.

[khaneliman]

This broke my config, in which I set

programs.firefox.profiles.<name>.userChrome = ''
<css>
'';

The error says that the string doesn't represent an absolute path.

It seems to fail while executing lib.pathIsDirectory.

Oops, thought we had basic tests already.. I'll add some tests and fix it.

[spikespaz]

Setting a string for me worked, pathIsDirectory should return null. It's possible that I misremember and cherry-picked the wrong commit.

[jvanbruegge]

The function seems to get tripped up by a URL, it complains about the first line of this:

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* set default namespace to XUL */

#webrtcIndicator {
  display: none !important;
}

[khaneliman]

I have a fix, just finishing up unit tests.