forbid-new-submodules marked not applicable on repo w/o submodules

[ChiefGokhlayeh]

This might be intended behavior, but I'd like to get confirmation.

Since 4.1.0, meta-hook check-hooks-apply marks forbid-new-submodules as "does not apply", if the repo does not contain any submodules.

The hook forbid-new-submodules itself correctly warns when adding submodules to a previously empty repo, so it technically does apply.

This might have to do with the changes introduced in #619.

Steps to reproduce:

1. Create new repo

   $ git init issue-707 && cd issue-707

2. Create .pre-commit-config.yaml with following content:

   repos:
     - repo: https://github.com/pre-commit/pre-commit-hooks
       rev: v4.1.0
       hooks:
         - id: forbid-new-submodules
     - repo: meta
       hooks:
         - id: check-hooks-apply

3. Commit .pre-commit-config.yaml

   $ git add .pre-commit-config.yaml && git commit -m "Add pre-commit config"

4. Run the following:

   $ pre-commit run --all
   forbid new submodules................................(no files to check)Skipped
   Check hooks apply to the repository......................................Failed
   - hook id: check-hooks-apply
   - exit code: 1
   
   forbid-new-submodules does not apply to this repository

5. Add submodule and force-commit

   $ git submodule add https://github.com/pre-commit/pre-commit-hooks.git
   $ git commit -m "Add some submodule" -n

6. Run the following:

   $ pre-commit run --all
   forbid new submodules....................................................Passed
   Check hooks apply to the repository......................................Passed

[asottile]

indeed this is a bit of a tricky case -- admittedly the original forbid-new-submodules was designed for a migration where submodules were slowly removed over time (and wasn't necessary afterwards)

#619 changed how the hook matches files which causes it to no longer match on a repo without submodules

[ChiefGokhlayeh]

I admit, the chances of someone accidentally adding a submodule are very slim. I simply added it to all my configs as a nice to have.

If this is a "won't fix", feel free to close the issue. I can simply remove the hook where no longer applicable.

[asottile]

you can maybe restore the old behaviour by overriding types: [] but then it probably does more work than it needs to

[asottile]

I think the resolution of this is "use this while migrating away from submodules" and once you're done you can replace it with a simple language: fail hook:

-   repo: local
    hooks:
    -   id: no-submodules
        name: no submodules
        language: fail
        entry: submodules are not allowed in this repository
        types: [directory]