How do I set up a lefthook in monorepo, housing several disparate Python projects?

[adam-ryczkowski-surfshark]

I'm looking for the pre-commit alternative that supports a monorepo design.

Our repository consists of numerous independent projects (mostly Python), each with their own pyproject.toml, tests and, most importantly, pre-commit hooks configuration.

I know that we cannot continue with pre-commit because

1. its configuration must be in the repository root (Guidance on pre-commit + monorepos pre-commit/pre-commit#466 (comment)), and
2. inability to limit checks to a subdirectory (No way to properly run hooks into subdirectory pre-commit/pre-commit#1417 (comment))
3. inability to run checkers from a subdirectory (How to run pre-commit inside folder pre-commit/pre-commit#1110 (comment)).

It is also worth noting, that unless someone volunteers to fork pre-commit, these features are unlikely to be implemented (pre-commit/pre-commit#1110 (comment))

How does lefthook support large monorepos? Does it support configuration nesting in subdirectories? Is there a way to specify a files to run on with a wildcard? The latter should be pretty-simple to do, and would be a viable walkaround for us in the time-being.

[mrexox]

Hey! Lefthook has a few features for monorepo, but it still has the main configuration file in the repo root.

However you can split the configuration across subfolders, for example:

# lefthook.yml

extends:
  - project1/lefthook.yml
  - project2/lefthook.yml

# project1/lefthook.yml

pre-commit:
  jobs:
    name: 'Project 1'
    root: project1/
    group:
      jobs:
        - run: ... whatever command to run within project1/ group
        - run: ...

# project2/lefthook.yml

pre-commit:
  jobs:
    name: 'Project 2'
    root: project2/
    group:
      jobs:
        - run: ... whatever command to run within project1/ group
        - run: ...

See jobs, group, root options documentation.

Lefthook will merge all files in extends, so you should configure carefully, not forgetting about root option.

[adam-ryczkowski-surfshark]

Thank you very much for the answer.

This news is good enough for now. In a long term I would prefer if the root config item was outside the projectX/lefthook.yml so we have a viable way of maintaining one of our subprojects as a separate git repository mirrored with the use of git subtree on our monorepo, but this is not a priority right now.

I really appreciate the fact that you, as a main maintainer, answered so quickly.

[mrexox]

Lefthook has issues with git submodules because it assumes that the git root is the project root which is not so in case of submodules. I never tested lefthook with subtrees, so I don't want to encourage you that it would work. But I believe that if there's a small issue it must be fixable, so feel free to file a bug/feature request.

[danciudev]

Hello, I’m currently migrating from Husky + lint-staged, and before finding this discussion I found it quite confusing to follow the documentation to achieve this setup. I think the section covering monorepositories with shared configuration could benefit from more clarity and emphasis.

Thank you very much for this fantastic open source project!