Allow skipping hooks in certain git states: merge and/or rebase

[DmitryTsepelev]

skip now allows to skip a certain hook during merge or rebase, configuration example:

pre-commit:
  commands:
    commit-colors:
      run: commit-colors $(git rev-parse HEAD)
  skip:
    - merge
    - rebase

Things to do:

• make it work on Windows
• update docs

Things to discuss:

• should we refactor run and run_windows to avoid duplicating the code?
• is there a better name than skip_git_states? using old skip option
• is there a better way to determine that merge or rebase are happening?

Closes #115

[Envek]

Oh, yes, I want it so bad!

This is especially useful for post-checkout hook (as in our Lefthook, Crystalball, and git magic for smooth development experience blog post) as usually you don't want to run such things during git pull --rebase and so on.

And this is a good reason to bump version :-)

---

is there a better name than skip_git_states?

What about using existing boolean skip directive (allow it to also receive strings or arrays)? Something like this:

pre-push:
  commands:
    packages-audit:
      skip:
       - merge
       - rebase

[DmitryTsepelev]

Changes:

• renamed the option to skip;
• added docs;
• moved duplicated functions from run and run_windows to a separate file (not sure what I'm doing).

Announcement: I have never tested it on windows!

[aminya]

Also fixes #102

[Envek]

Build with goreleaser build --skip-validate --rm-dist isn't passing with following error:

   ⨯ build failed after 1.67s error=failed to build for windows_amd64: # github.com/evilmartians/lefthook/cmd
cmd/run_windows.go:14:2: imported and not used: "sort"
cmd/run_windows.go:22:2: imported and not used: "github.com/gobwas/glob"

[DmitryTsepelev]

Had to make a new branch and copy changes since there were lots of conflicts 🙈

[Envek]

Seems like there is some validation of config types exists that prevents it from working.

Given following lefthook.yml:

post-checkout:
  piped: true
  scripts:
    01-bundle-checkinstall:
      skip: true
      tags: backend
    02-db-migrate:
      skip: true
      tags: backend
    03-crystalball-update:
      skip: true
      tags: rspec backend

And following lefthook-local.yml:

post-checkout:
  piped: true
  scripts:
    01-bundle-checkinstall:
      skip: false
    02-db-migrate:
      skip: rebase
    03-crystalball-update:
      skip:
        - rebase
        - merge

Checkout to another branch (without merge or rebase in progress) produces following output:

$ git checkout master

ERROR 2021/05/22 12:16:28 svType != tvType; key=skip, st=string, tt=bool, sv=rebase, tv=true
ERROR 2021/05/22 12:16:28 svType != tvType; key=skip, st=[]interface {}, tt=bool, sv=[rebase merge], tv=true
Lefthook v0.7.5
RUNNING HOOKS GROUP: post-checkout

  EXECUTE > 01-bundle-checkinstall
The Gemfile's dependencies are satisfied

02-db-migrate (SKIP BY SETTINGS)

03-crystalball-update (SKIP BY SETTINGS)

SUMMARY: (done in 0.36 seconds)

Expected result: all steps are run

Actual result: steps 2 and 3 are skipped, type errors are printed to console

[Envek]

One more thing is git worktree support.

As every worktree can do rebases and merges independently from main worktree, every worktree has its own git directory (which can be retrieved with git rev-parse --git-dir command) where we need to search for merge and rebase files (however, hooks are global for all worktrees and are only stored in global worktree).

For example, if we have repository ~/foo with worktree ~/foo-wt and both are during rebase, directory structure will be as follows:

1. For main repo:
   • root url: ~/foo
   • git dir: ~/foo/.git (here will be REBASE_HEAD for main tree)
   • git hooks dir: ~/foo/.git/hooks
2. For worktree foo-wt:
   • root url: ~/foo-wt
   • git dir: ~/foo/.git/worktrees/foo-wt (here will be REBASE_HEAD for worktree)
   • git hooks dir: ~/foo/.git/hooks (same as for the main repo)

These are output of git rev-parse --show-toplevel, git rev-parse --git-dir, and git rev-parse --git-path hooks commands respectively.

Looks like that we need one more helper like getGitDir that will return path from git rev-parse --git-dir command (see #177 for reference).

[Envek]

Inside git worktrees, getRootPath(), ".git" will be a file, not directory! Also every worktree has its own git directory placed inside .git directory of the main worktree 🤯

[DmitryTsepelev]

Fixed

[Envek]

And fixed one more time for worktrees (pushed commit right into your pull request, sorry!)

[Envek]

I wonder, whether can we check for single REBASE_HEAD file instead of this two checks? 🤔

Also here we need to use output of git rev-parse --git-dir command to get .git directory for worktrees.

[DmitryTsepelev]

Looks like REBASE_HEAD exists only when it's an "interactive rebase or when rebase is stopped because of conflicts"

[Envek]

Yeah, official git prompts also checks for these directories, so let's keep it as it is: https://github.com/git/git/blob/de88ac70f3a801262eb3aa087e5d9a712be0a54a/contrib/completion/git-prompt.sh#L446-L462

[DmitryTsepelev]

Talkin about merging configs: looks like Viper does not support merging values of different types. Looks like we have to either change our API (e.g., bring back a separate skip_git_stages key) or hack around Viper (because I believe they won't accept a PR allowing to prefer boolean over anything else). Thoughts?

[Envek]

For now I created issue in Viper for this (spf13/viper#1142) as I wish that we could reuse the same skip setting.

However, it is probably quite a rare use case (when hooks are always disabled in main config, and only during merge/rebase in local config), so may be we can safely ignore it for now?

[DmitryTsepelev]

Yeah, we can add a separate issue for that and see if it's a big deal. Would be really nice for Viper to handle it for us!

[Envek]

Thank you, @DmitryTsepelev, amazing work!

[Envek]

Finally released in 0.8.0