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Pre-commit Hooks

Pre-commit hooks prevent broken code from being committed. Every commit is automatically checked for lint errors, formatting issues, and type errors before it enters git history.

Setup (Both Repos)​

Install Husky + lint-staged​

# In TrickList/ or Backend/
npm install --save-dev husky lint-staged

# Initialize Husky
npx husky init

This creates a .husky/ directory with a pre-commit hook.

Configure the Hook​

Replace .husky/pre-commit contents:

npx lint-staged

Configure lint-staged​

Add to package.json:

TrickList (Mobile)​

{
  "lint-staged": {
    "*.{ts,tsx}": [
      "biome check --write --no-errors-on-unmatched",
      "biome format --write --no-errors-on-unmatched"
    ],
    "*.{json,md}": [
      "biome format --write --no-errors-on-unmatched"
    ]
  }
}

Backend​

{
  "lint-staged": {
    "*.js": [
      "biome check --write --no-errors-on-unmatched",
      "biome format --write --no-errors-on-unmatched"
    ],
    "*.{json,md}": [
      "biome format --write --no-errors-on-unmatched"
    ]
  }
}

What Runs on Commit​

git commit -m "feat: add trick list"
       │
       ▼
  lint-staged
       │
       ├── biome check --write (lint + auto-fix staged files)
       ├── biome format --write (format staged files)
       │
       ▼
  Pass? ──── Yes ──── Commit created
       │
       No
       │
       ▼
  Commit blocked, errors printed

Only staged files are checked, so it's fast even in large repos.

Optional: Add Typecheck​

For TrickList, you can add a full typecheck on commit. This is slower but catches type errors:

{
  "lint-staged": {
    "*.{ts,tsx}": [
      "biome check --write --no-errors-on-unmatched",
      "biome format --write --no-errors-on-unmatched"
    ]
  },
  "scripts": {
    "precommit:typecheck": "tsc --noEmit"
  }
}

And update .husky/pre-commit:

npx lint-staged
npm run precommit:typecheck

Bypassing Hooks​

In rare cases (emergency hotfix, WIP commit), hooks can be bypassed:

git commit --no-verify -m "hotfix: emergency fix"

This should be rare. CI will still catch any issues on the PR.

Troubleshooting​

Hook not running​

# Ensure hooks are executable
chmod +x .husky/pre-commit

# Reinstall hooks
npx husky install

Biome not found​

# Ensure it's in devDependencies
npm install --save-dev @biomejs/biome