Make `hjem.extraModules` a single module instead of a list

[player131007]

Since we can merge deferredModules, hjem.extraModules doesn't need to be a list anymore. However, changing the type directly might be too big a breaking change. What do you think is the best course of action?

[eclairevoyant]

What's the benefit? To not have to type []?

[player131007]

What's the benefit? To not have to type []?

yes.

[eclairevoyant]

PRs with tests are welcome, as long as it doesn't break the existing type. We're not planning to prioritise this one though.

[plumj-am]

@player131007 you can make a little wrapper for this, I do it here in my configs:

      options.hjem.extraModule = mkOption {
        type = nullOr deferredModule;
        default = null;
        description = ''
          Single module to be evaluated as a part of the users module
          inside `config.hjem.users.<username>`. Use this instead of
          `extraModules` when you only have one module to add.
        '';
      };

      config.hjem.extraModules =
        optional (config.hjem.extraModule != null) config.hjem.extraModule;

Then use as:

hjem.extraModule = { };

It works for me :]