Pre-commit Hooks

About 682 wordsAbout 2 min

2025-01-16

Run golint-sl automatically before every commit to catch issues early. The hooks build a custom golangci-lint binary with golint-sl and run it on your code.

Prerequisites

Your project must have both .custom-gcl.yml and .golangci.yml configured. See Installation for setup.

Using pre-commit Framework

pre-commit is a framework for managing git hooks. golint-sl provides official hook definitions.

Setup

Install pre-commit:

# macOS
brew install pre-commit

# pip
pip install pre-commit

Create .pre-commit-config.yaml in your project root:

repos:
  - repo: https://github.com/SpechtLabs/golint-sl
    rev: v0.1.0  # Use the latest release
    hooks:
      - id: golint-sl

Install the hooks:
```
pre-commit install
```

Available Hooks

golint-sl provides two hooks:

Hook ID	Description	Speed
`golint-sl`	Builds `custom-gcl` and runs on all packages (`./...`)	Thorough
`golint-sl-pkg`	Builds `custom-gcl` and runs only on changed packages	Fast

For large repositories, use golint-sl-pkg for faster feedback:

repos:
  - repo: https://github.com/SpechtLabs/golint-sl
    rev: v0.1.0
    hooks:
      - id: golint-sl-pkg  # Only check changed packages

Tips

The hooks require golangci-lint to be installed and available in your PATH. The custom binary is built automatically during the hook run.

Running Manually

Run all hooks on all files:

pre-commit run --all-files

Run only golint-sl:

pre-commit run golint-sl --all-files

Skipping Hooks

For a single commit (use sparingly):

git commit --no-verify -m "WIP: quick fix"

Warning

Skipping hooks should be rare. If you're skipping frequently, consider fixing the underlying issues.

Using Git Hooks Directly

If you prefer not to use pre-commit, set up git hooks manually.

Simple Pre-commit Hook

Create .git/hooks/pre-commit:

#!/bin/bash

# Build custom binary if it doesn't exist
if [ ! -f ./custom-gcl ]; then
    echo "Building custom golangci-lint with golint-sl..."
    golangci-lint custom
fi

echo "Running golint-sl..."
./custom-gcl run ./...
exit_code=$?

if [ $exit_code -ne 0 ]; then
    echo "golint-sl found issues. Please fix them before committing."
    exit 1
fi

exit 0

Make it executable:

chmod +x .git/hooks/pre-commit

Staged Files Only

Check only staged Go files for faster feedback:

#!/bin/bash

# Get staged .go files
staged_go_files=$(git diff --cached --name-only --diff-filter=ACM | grep '\.go$')

if [ -z "$staged_go_files" ]; then
    # No Go files staged, skip
    exit 0
fi

# Build custom binary if it doesn't exist
if [ ! -f ./custom-gcl ]; then
    echo "Building custom golangci-lint with golint-sl..."
    golangci-lint custom
fi

echo "Running golint-sl on staged files..."

# Get unique package directories
packages=$(echo "$staged_go_files" | xargs -I {} dirname {} | sort -u | sed 's|^|./|')

./custom-gcl run $packages
exit_code=$?

if [ $exit_code -ne 0 ]; then
    echo "golint-sl found issues. Please fix them before committing."
    exit 1
fi

exit 0

Git hooks aren't versioned by default. To share hooks with your team:

Create a scripts/hooks/ directory:
```
mkdir -p scripts/hooks
```
Add your hook scripts there
Add setup instructions to your README with the command git config core.hooksPath scripts/hooks

Configuration

golint-sl picks up your .golangci.yml configuration automatically. Disable analyzers that are too noisy for pre-commit:

# .golangci.yml
version: "2"

linters:
  enable:
    - golint-sl

  settings:
    custom:
      golint-sl:
        type: module
        description: SpechtLabs Go linter collection
        original-url: github.com/spechtlabs/golint-sl
        settings:
          disabled-analyzers:
            - todotracker
            - exporteddoc

Troubleshooting

Hook Not Running

Ensure the hook is installed:

# pre-commit framework
pre-commit install

# Manual hooks
ls -la .git/hooks/pre-commit

golangci-lint Not Found

The hook requires golangci-lint to be installed:

# Check installation
which golangci-lint

# Install if needed
curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v2.8.0

Too Slow

For large codebases:

Use golint-sl-pkg to check only changed packages

Disable expensive analyzers in .golangci.yml:

settings:
  custom:
    golint-sl:
      type: module
      settings:
        disabled-analyzers:
          - dataflow  # SSA analysis is slower

Run full checks in CI instead

Next Steps

GitHub Actions - Comprehensive CI checks
Configure Analyzers - Tune which analyzers run