# Pre-commit Local Setup (uv)

## What is pre-commit?

`pre-commit` runs checks before each commit (for example: formatting and file sanity checks).

This repository uses pre-commit locally only. Bitbucket Pipelines does not run pre-commit.

## Install and set up locally (with uv)

1. Install `uv` (if not installed):

```bash
# Windows (PowerShell)
powershell -c "irm https://astral.sh/uv/install.ps1 | iex"

# macOS/Linux
curl -LsSf https://astral.sh/uv/install.sh | sh
```

2. Install all dependencies (including pre-commit):

```bash
uv sync --group dev
```

3. Install git hooks in this repo:

```bash
uv run pre-commit install
```

## How it works

When you run `git commit`, pre-commit automatically runs these checks on your staged files:

| Hook | What it does | Auto-fix? |
|---|---|---|
| `trailing-whitespace` | Removes spaces at end of lines | Yes |
| `end-of-file-fixer` | Ensures files end with a newline | Yes |
| `check-yaml` | Validates YAML syntax | Manual fix |
| `check-json` | Validates JSON syntax | Manual fix |
| `check-merge-conflict` | Detects `<<<<<<<` conflict markers | Manual fix |
| `check-added-large-files` | Blocks files larger than 500KB | Manual fix |

- **Pass** -> commit goes through
- **Fail (auto-fix)** -> commit blocked, files fixed, re-stage and commit again
- **Fail (manual fix)** -> commit blocked, fix the error, re-stage and commit again

## Common commands

Run on all files:

```bash
uv run pre-commit run --all-files
```

Run on staged files (happens automatically on commit):

```bash
uv run pre-commit run
```