ncmpcpp: add module

[olmokramer]

Description

Adds a module for https://github.com/ncmpcpp/ncmpcpp. All settings are configured through a single settings attrset, except for mpd_music_dir, which has its own dedicated option. If it is set to null (the default) its value is taken from services.mpd.musicDirectory and services.mpd.enable is required to be true.

Checklist

• Change is backwards compatible.

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all.

• 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.

  • Added myself and the module files to .github/CODEOWNERS.

[olmokramer]

We could get rid of this option and place it under settings if settings were a freeform module, but that breaks the tests with an error:

Module `:anon-1:anon-1' has an unsupported attribute `freeformType'.
This is caused by introducing a top-level `config' or `options'
attribute. Add configuration attributes immediately on the top level
instead, or move all of them (namely: freeformType) into the
explicit `config' attribute.

The Freeform modules PR has only been merged 12 days ago, though, so it may not be a great idea to start relying on it already.

[olmokramer]

This is what that might look like https://github.com/olmokramer/home-manager/blob/ncmpcpp-freeform/modules/programs/ncmpcpp.nix

[rycee]

Cool. I'll have to check out 🙂

[olmokramer]

Thanks for the review! I have implemented all your suggestions except for the bindings type, and added a warning if both programs.ncmpcpp.mpdMusicDir and programs.ncmpcpp.settings.mpd_music_dir are set.

[olmokramer]

Thanks again! I've applied your changes and added a with lib; at the top, since all modules seem to do that and you seem to be expecting that as well :)

[olmokramer]

Ok I've changed the default value of programs.ncmpcpp.mpdMusicDir to only use the MPD configuration on Linux platforms. Still not quite sure what you meant with your last comment.

I've also "resolved" the comments that I have addressed for my own convenience, but feel free to "unresolve" them if you think they deserve more attention :)

[olmokramer]

I've moved the test of the MPD configuration to a new directory and only run it on Linux now.

Also rebuilt the documentation one last time, and I noticed that the default for programs.ncmpcpp.mpdMusicDir is not rendered literally, i.e. the newlines and indentation are removed. Is there some alternative to literalExample that is supposed to be used for the default value? Or is the default value text never rendered literally?

[rycee]

Thanks! Rebased to master in 4b702bf.