| name | prek |
| plugin | coding |
| description | Set up code formatting and pre-commit hooks using prek (fast Rust-based alternative to pre-commit) with prek.toml config. Use whenever the user wants to configure prek, add formatters, set up pre-commit hooks, or enforce code style. Triggers on "set up prek", "add formatting", "configure formatters", "pre-commit setup", "add ruff", "set up prettier", "configure sqlfmt". Works on new and existing projects. Always use when init-app-stack has just run.
|
Prek — Pre-commit Formatter Setup
prek is a fast, Rust-native drop-in alternative to
pre-commit. It reads prek.toml and runs formatters automatically on staged
files at commit time.
Formatters — all use 4 spaces, no tabs, line-length 120:
- Python: ruff-check --fix + ruff-format (via astral-sh/ruff-pre-commit)
- SQL:
uv run sqlfmt (local hook)
- TypeScript/JS:
bunx --bun prettier --write (local hook)
- YAML: builtin check-yaml (if .yaml/.yml files present)
Step 0: Ensure prek is installed
prek --version
If not installed, the simplest install for this stack is:
uv tool install prek
Other options: brew install prek, winget install --id j178.Prek, or download
binary from https://github.com/j178/prek/releases.
Step 1: Detect file types in the project
find . -name "*.py" -not -path "./.git/*" -not -path "./node_modules/*" | head -1
find . -name "*.sql" -not -path "./.git/*" | head -1
find . \( -name "*.ts" -o -name "*.tsx" -o -name "*.js" -o -name "*.jsx" \) \
-not -path "./.git/*" -not -path "./node_modules/*" | head -1
find . \( -name "*.yaml" -o -name "*.yml" \) -not -path "./.git/*" | head -1
Include a repo/hook only when matching files exist. On a freshly scaffolded
project with no files yet, use the declared stack to decide.
Step 2: Write prek.toml
Write prek.toml to the project root. The structure mirrors pre-commit's
[[repos]] / hooks model — each [[repos]] block is a hook source.
[[repos]]
repo = "builtin"
hooks = [
{ id = "check-yaml" },
]
[[repos]]
repo = "https://github.com/astral-sh/ruff-pre-commit"
rev = "v0.11.0"
hooks = [
{ id = "ruff-check", args = ["--fix"] },
{ id = "ruff-format" },
]
[[repos]]
repo = "local"
hooks = [
{ id = "sqlfmt", name = "sqlfmt", language = "system", entry = "uv run sqlfmt", files = '\\.sql$' },
]
[[repos]]
repo = "local"
hooks = [
{ id = "prettier", name = "prettier", language = "system", entry = "bunx --bun prettier --write", files = '\\.(ts|tsx|js|jsx|vue)$' },
]
Tip on ruff rev: run uv run ruff --version in the project to see the
installed version, then use the matching tag from the ruff-pre-commit releases.
Step 3: Update pyproject.toml
If pyproject.toml exists or Python files are present, add/merge these
sections. Don't overwrite keys the user already set:
[tool.ruff]
line-length = 120
indent-width = 4
target-version = "py313"
[tool.ruff.format]
indent-style = "space"
quote-style = "double"
line-ending = "auto"
[tool.sqlfmt]
line_length = 120
Step 4: Write .prettierrc
If TypeScript/JavaScript files are present, write .prettierrc to the project
root (skip if one already exists with different settings — ask first):
{
"tabWidth": 4,
"useTabs": false,
"semi": true,
"singleQuote": false,
"printWidth": 120,
"trailingComma": "es5"
}
Step 5: Install the git hook
prek install
This writes .git/hooks/pre-commit automatically — no manual hook file needed.
Step 6: Run formatters on all existing files
prek run --all-files
If a tool is missing (prek not found, uv not installed, bunx not available),
report it clearly and suggest the install command. Don't fail silently.
After setup — tell the user
- Which hooks were installed and why (based on detected file types)
prek run --all-files runs all hooks manually on every file- The git hook fires automatically on
git commit
- What was added/merged into
pyproject.toml
