Option to Merge Multiple Seperate Configs

[JayRovacsek]

Hi! As always - thanks for all of the hard work within this repo!

I wasn't sure how to better describe the issue in the title, so please ask clarifying questions if I miss anything that might help. Both within my work settings and personal projects, we leverage git-hooks extensively.
One of the use cases is to leverage github actions, with a simple nix flake check command to validate post push, that even users whom may not leverage nix, have ensured no issues with proposed changes.
With a few custom check hooks we have, the runtime is great locally where the checks are only ran on in-scope files and based on the delta, whereas in CICD the run of-course incorporates all files for the checks component and may take minutes.

I'd like to be able to merge two or more check configurations into a final artefact in terms of a shell hook; something like:

          checks = {
            foo = git-hooks.lib.${system}.run {
              src = self;
              hooks.actionlint.enable = true;
            };

            bar = git-hooks.lib.${system}.run {
              src = self;
              hooks.black.enable = true;
            };

            baz = git-hooks.lib.${system}.run {
              src = self;
              hooks.deadnix.enable = true;
            };
         };
          devShells.default = pkgs.devshell.mkShell {
            # Here, normally this would simply be set to something such as self.checks.${system}.git-hooks.shellHook
            # rather than "placeholder" - but this is where an ability to merge settings would be really useful
            devshell.startup.git-hooks.text = "placeholder";
            name = "merged-checks-shell";
            packages = self.checks.${system}.foo.enabledPackages
              ++ self.checks.${system}.bar.enabledPackages
              ++ self.checks.${system}.baz.enabledPackages;
          };

I recognise this is an edge-case scenario, and could be worked around a few ways, but would enable users to avoid writing complex wrapper functions generally at the benefit of enabling the exposure of checks in a still consistent manner locally, but enabling parallel runs within settings such as github actions (as each check could be better exposed as a target via projects such as https://github.com/nix-community/nix-github-actions)

Thanks again for this awesome repo!

[JayRovacsek]

Digging into modules/pre-commit.nix it seems I could do the above via a single instance of a check that merges the enabled config.hooks value of all others but doesn't expose via the checks attribute.

Still keen for feedback / thoughts of-course! 😁