Adds a pre-commit hook (technically a pre-push hook) to the PyTorch repo.
**This is currently an opt-in feature**, which one can opt into by running `python scripts/setup_hooks.py` locally.
### Features
- **Run Lintrunner Before Push**: Before every `git push`, automatically runs lintrunner on your changes.
- Really need to skip the checks? Run `git push --no-verify`
- **Consistent, Isolated, Lintrunner Environment**: During pre-push, Lintrunner runs in it's own virtual en environment that contain all lintrunner dependencies in a consistent, isolated environment. No more lintrunner failures because you created a new .venv. (Did you know you needed to run `lintrunner init` every time you make a new .venv?)
- **Dependencies Automatically Updated**: If .lintrunner.toml is updated, this will automatically re-run `lintrunner init` to ensure you install the latest dependencies specified
### Installation
- Run `python scripts/setup_hooks.py`. Now every `git push` will first run lintrunner.
### Additional details
- The lintrunner used by the pre-push hook runs in a special per-repo virtual environment managed by the commit-hook tool located under `$USER/.cache/pre-commit`
- Does not affect your regularly used lintrunner
- Manual invocations of lintrunner will continue to depend on your local environment instead of the special pre-push one. If there's enough interest, we could explore consolidating them.
- Does not run `lintrunner -a` for you.
- You still need to manually run that (can be changed later though!)
- Have staged/unstaged changes? No worries
- This runs `git stash` before running the pre-commit hooks and pops back your changes afterwards, so only the changes actaully being pushed will be tested
### Downsides
- No streaming UI updates
- While you still get the same output from lintrunner that you're used to, the commit-hook framework doesn't show any output while lintrunner is actually running. Instead, it shows the entire output after linter has completed execution, which could be a few minutes (especially if it has to run `lintrunner init` first)
- `uv` installation is required to run the setup script. The setup script will ask users to install uv if it's not available.
- This is required to be able to install the pre-commit package in a safe way that's available no matter what .venv you are running in.
### Opting out
- Disable hook for a single push: Run `git push --no-verify`
- Disable hook permanently: If something goes wrong and you need to wipe your setup:
- Delete the `$USER/.cache/pre-commit` folder and the `.git/hooks/pre-push` file in your local repo.
- You can now rerun `python scripts/setup_hooks.py` to setup your git push hook again if you want.
### Potential Future Changes
Things that could be done to make this even better if folks like these ideas:
- Automatic setup
- Our `CONTRIBUTING.md` file tells devs to run `make setup-env`. That could be a good entry point to hook the installation into
- Fix the console output streaming
- Make every lintrunner invocation (including manual ones) use the same repo-specific venv that the commit-hook uses.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/158389
Approved by: https://github.com/seemethere
