Quality Gates

Standards and patterns for maintaining code quality through automated gates, hooks, testing, and continuous integration.

Philosophy

Quality gates prevent problems before they reach production. Automated checks provide immediate feedback, enforce standards consistently, and free developers to focus on building features rather than remembering process.

Progressive enforcement:

• Pre-commit: Fast checks (lint, format, typecheck) on staged files only
• Pre-push: Comprehensive checks (full test suite, coverage)
• CI/CD: Production-ready validation (build, E2E tests, security scans)

Git Hooks: Lefthook (Recommended)

Why Lefthook over Husky:

• Language-agnostic: Go binary, no Node.js dependency
• Faster: Built in Go, parallel execution by default
• Simpler: YAML configuration, combines Husky + lint-staged functionality
• Lightweight: Single binary, smaller footprint
• Modern: Actively maintained by Evil Martians (2025 recommendation)

Installation

# Install via package manager of choice
pnpm add -D lefthook
# or npm install -D lefthook
# or brew install lefthook (global)

# Initialize lefthook
pnpm lefthook install
# This creates .lefthook directory and configures git hooks

Configuration: lefthook.yml

Basic Setup (Next.js/TypeScript project):

# lefthook.yml - Place in project root
pre-commit:
  parallel: true  # Run commands in parallel for speed
  commands:
    lint:
      glob: "*.{js,ts,jsx,tsx}"
      run: pnpm eslint --fix {staged_files}
      stage_fixed: true  # Re-stage files after fixing

    format:
      glob: "*.{js,ts,jsx,tsx,json,md,css}"
      run: pnpm prettier --write {staged_files}
      stage_fixed: true

    typecheck:
      glob: "*.{ts,tsx}"
      run: pnpm tsc --noEmit
      # Note: Only checks, doesn't fix

pre-push:
  commands:
    test:
      run: pnpm test:ci
      # Full test suite with coverage

    build:
      run: pnpm build
      # Ensure production build succeeds

commit-msg:
  commands:
    commitlint:
      run: pnpm commitlint --edit {1}
      # Enforce conventional commits

Advanced: Monorepo with Multiple Packages

pre-commit:
  parallel: true
  commands:
    # Package-specific linting
    lint-web:
      glob: "apps/web/**/*.{ts,tsx}"
      run: pnpm --filter web lint --fix {staged_files}
      root: apps/web/
      stage_fixed: true

    lint-api:
      glob: "apps/api/**/*.ts"
      run: pnpm --filter api lint --fix {staged_files}
      root: apps/api/
      stage_fixed: true

    # Shared package linting
    lint-shared:
      glob: "packages/**/*.{ts,tsx}"
      run: pnpm --filter @repo/* lint --fix {staged_files}
      stage_fixed: true

    # Global formatting
    format:
      glob: "**/*.{js,ts,jsx,tsx,json,md}"
      run: pnpm prettier --write {staged_files}
      stage_fixed: true

pre-push:
  commands:
    # Run tests for changed packages only
    test-changed:
      run: pnpm turbo run test --filter=[HEAD^1]

    # Type check all packages
    typecheck:
      run: pnpm turbo run typecheck

    # Build all packages
    build:
      run: pnpm turbo run build

Convex-Specific Hooks

pre-commit:
  parallel: true
  commands:
    # Standard linting/formatting
    lint:
      glob: "*.{js,ts,jsx,tsx}"
      run: pnpm eslint --fix {staged_files}
      stage_fixed: true

    # Convex function validation
    convex-typecheck:
      glob: "convex/**/*.ts"
      run: pnpm tsc --noEmit --project convex/tsconfig.json

    # Convex schema validation (if you have validation scripts)
    convex-schema:
      glob: "convex/schema.ts"
      run: pnpm convex dev --once --run convex/validateSchema.ts
      # Only run if schema changed

pre-push:
  commands:
    test:
      run: pnpm test:ci

    # Deploy to preview environment for testing
    convex-preview:
      run: |
        pnpm convex deploy --preview-name ci-$(git rev-parse --short HEAD)
        echo "Preview deployed to: $(pnpm convex dashboard --preview-name ci-$(git rev-parse --short HEAD))"

Skip Hooks (Emergency Use Only)

# Skip pre-commit hooks (use sparingly!)
git commit --no-verify -m "emergency fix"

# Skip pre-push hooks
git push --no-verify

# Skip specific lefthook command
LEFTHOOK_EXCLUDE=test git push

Testing Strategy: Vitest

Why Vitest:

• Fast, modern test runner
• Jest-compatible API (easy migration)
• Great TypeScript support
• Built-in coverage with c8/v8
• Watch mode with intelligent re-runs

Configuration

// vitest.config.ts
import { defineConfig } from 'vitest/config'
import react from '@vitejs/plugin-react'
import path from 'path'

export default defineConfig({
  plugins: [react()],
  test: {
    globals: true,
    environment: 'jsdom',
    setupFiles: './test/setup.ts',
    include: ['**/*.{test,spec}.{js,ts,jsx,tsx}'],
    exclude: ['**/node_modules/**', '**/dist/**', '**/.next/**'],
    coverage: {
      provider: 'v8',
      reporter: ['text', 'json', 'html', 'lcov'],
      exclude: [
        '**/node_modules/**',
        '**/dist/**',
        '**/.next/**',
        '**/test/**',
        '**/*.config.{js,ts}',
        '**/*.d.ts',
      ],
      // Don't enforce arbitrary thresholds
      // Use coverage to find untested paths, not as success metric
      thresholds: {
        lines: 60,    // Baseline, not target
        functions: 60,
        branches: 60,
        statements: 60,
      },
    },
  },
  resolve: {
    alias: {
      '@': path.resolve(__dirname, './src'),
    },
  },
})

Package.json Scripts

{
  "scripts": {
    "test": "vitest",
    "test:ui": "vitest --ui",
    "test:ci": "vitest run --coverage",
    "test:watch": "vitest --watch",
    "typecheck": "tsc --noEmit",
    "lint": "eslint . --ext .ts,.tsx,.js,.jsx",
    "lint:fix": "eslint . --ext .ts,.tsx,.js,.jsx --fix",
    "format": "prettier --write \"**/*.{ts,tsx,js,jsx,json,md,css}\"",
    "format:check": "prettier --check \"**/*.{ts,tsx,js,jsx,json,md,css}\""
  }
}

CI/CD: GitHub Actions

Why GitHub Actions:

• Native GitHub integration
• Free for public repos, generous free tier for private
• Matrix builds for testing multiple environments
• Artifact storage and caching
• Secrets management

Basic Workflow

# .github/workflows/ci.yml
name: CI

on:
  pull_request:
    branches: [main, develop]
  push:
    branches: [main, develop]

jobs:
  quality-checks:
    name: Quality Checks
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Setup pnpm
        uses: pnpm/action-setup@v2
        with:
          version: 8

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '22'
          cache: 'pnpm'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Lint
        run: pnpm lint

      - name: Type check
        run: pnpm typecheck

      - name: Test
        run: pnpm test:ci

      - name: Upload coverage
        uses: codecov/codecov-action@v4
        with:
          files: ./coverage/coverage-final.json
          fail_ci_if_error: false

      - name: Build
        run: pnpm build

      - name: Upload build artifacts
        uses: actions/upload-artifact@v4
        with:
          name: build-output
          path: .next/
          retention-days: 7

Advanced: Matrix Testing + E2E

# .github/workflows/comprehensive-ci.yml
name: Comprehensive CI

on:
  pull_request:
    branches: [main]
  push:
    branches: [main]

jobs:
  # Unit and integration tests across Node versions
  test-matrix:
    name: Test (Node ${{ matrix.node-version }})
    runs-on: ubuntu-latest

    strategy:
      matrix:
        node-version: [20, 22]

    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v2
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
          cache: 'pnpm'

      - run: pnpm install --frozen-lockfile
      - run: pnpm test:ci
      - run: pnpm build

  # E2E tests with Playwright
  e2e:
    name: E2E Tests
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v2
      - uses: actions/setup-node@v4
        with:
          node-version: '22'
          cache: 'pnpm'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Install Playwright browsers
        run: pnpm playwright install --with-deps chromium

      - name: Build application
        run: pnpm build

      - name: Run E2E tests
        run: pnpm test:e2e
        env:
          PLAYWRIGHT_BROWSERS_PATH: 0

      - name: Upload test results
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: playwright-report
          path: playwright-report/
          retention-days: 30

  # Security scanning
  security:
    name: Security Scan
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v2
      - uses: actions/setup-node@v4
        with:
          node-version: '22'
          cache: 'pnpm'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Audit dependencies
        run: pnpm audit --audit-level=moderate

      - name: Check for vulnerabilities
        run: pnpm dlx @socketsecurity/cli audit

Convex-Specific CI

# .github/workflows/convex-ci.yml
name: Convex CI

on:
  pull_request:
    branches: [main]
    paths:
      - 'convex/**'
      - 'src/**'

jobs:
  convex-validate:
    name: Validate Convex Functions
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v2
      - uses: actions/setup-node@v4
        with:
          node-version: '22'
          cache: 'pnpm'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Type check Convex functions
        run: pnpm tsc --noEmit --project convex/tsconfig.json

      - name: Deploy to preview
        env:
          CONVEX_DEPLOY_KEY: ${{ secrets.CONVEX_DEPLOY_KEY }}
        run: |
          pnpm convex deploy --preview-name pr-${{ github.event.pull_request.number }}

      - name: Run Convex tests
        run: pnpm test:convex

      - name: Comment preview URL
        uses: actions/github-script@v7
        with:
          script: |
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: `🚀 Convex preview deployed: https://dashboard.convex.dev/t/pr-${{ github.event.pull_request.number }}`
            })

Branch Protection

Configure in GitHub Settings → Branches → Branch protection rules for main:

Required settings:

• ✅ Require a pull request before merging
• ✅ Require approvals: 1
• ✅ Require status checks to pass before merging
  • Select: Quality Checks, Test, Build, E2E Tests
• ✅ Require branches to be up to date before merging
• ✅ Require conversation resolution before merging
• ✅ Do not allow bypassing the above settings

Optional but recommended:

• ✅ Require signed commits
• ✅ Require linear history
• ✅ Lock branch (for production branches)

Coverage Reporting: Codecov

Setup:

1. Sign up at codecov.io with GitHub
2. Add repository
3. Add Codecov token to GitHub secrets: CODECOV_TOKEN
4. Configure codecov.yml in project root:

# codecov.yml
coverage:
  status:
    project:
      default:
        target: auto  # Maintain current coverage
        threshold: 5%  # Allow 5% decrease
        if_ci_failed: error

    patch:
      default:
        target: 70%  # New code should be well-tested
        if_ci_failed: error

comment:
  layout: "reach, diff, flags, files"
  behavior: default
  require_changes: false

ignore:
  - "**/*.test.ts"
  - "**/*.spec.ts"
  - "**/*.config.ts"
  - "**/*.d.ts"
  - "**/test/**"
  - "**/__tests__/**"

Quality Checklist

When setting up quality gates for a new project:

Essential (Must Have)

• Lefthook configured with pre-commit (lint, format, typecheck)
• Lefthook configured with pre-push (test, build)
• GitHub Actions CI with lint, typecheck, test, build
• Branch protection enabled on main branch
• Test framework set up (Vitest recommended)
• Code coverage reporting (Codecov or similar)

Recommended (Should Have)

• E2E testing with Playwright for critical paths
• Dependency audit in CI (pnpm audit)
• Conventional commits enforcement (commitlint)
• Coverage thresholds as diagnostic (not arbitrary targets)
• Security scanning in CI
• Preview deployments for PRs

Nice to Have

• Matrix testing across Node versions
• Performance budgets enforced
• Bundle size tracking in CI
• Accessibility testing automated
• Visual regression testing for UI projects

Anti-Patterns to Avoid

❌ Husky: Use Lefthook (faster, language-agnostic, simpler) ❌ Arbitrary coverage targets: Use coverage to find gaps, not as success metric ❌ Testing implementation details: Test behavior, not internals ❌ Heavy mocking: Minimize mocks, prefer real integration tests ❌ Skipping hooks routinely: Fix the problem, don't bypass gates ❌ CI that only tests on main: Test on every PR ❌ No branch protection: Enforce quality before merge ❌ Manual version bumping: Automate with changesets/semantic-release

Example: Full Project Setup

# 1. Initialize project
pnpm init

# 2. Install quality tools
pnpm add -D \
  lefthook \
  vitest @vitest/coverage-v8 \
  @testing-library/react @testing-library/jest-dom \
  eslint @typescript-eslint/parser @typescript-eslint/eslint-plugin \
  prettier eslint-config-prettier \
  @commitlint/cli @commitlint/config-conventional

# 3. Initialize lefthook
pnpm lefthook install

# 4. Create configurations
# - lefthook.yml (git hooks)
# - vitest.config.ts (testing)
# - .github/workflows/ci.yml (CI/CD)
# - .prettierrc (formatting)
# - .eslintrc.js (linting)
# - commitlint.config.js (commit message validation)
# - codecov.yml (coverage reporting)

# 5. Add scripts to package.json
# (see scripts section above)

# 6. Configure GitHub branch protection

# 7. First commit
git add .
git commit -m "feat: setup quality gates infrastructure"
# Lefthook will run pre-commit hooks automatically

Philosophy

Quality is not a phase—it's built into the process.

• Fast feedback loops (pre-commit) catch trivial issues
• Comprehensive validation (pre-push) prevents broken work from reaching CI
• CI/CD enforces production-readiness
• Branch protection ensures every change meets standards

Coverage is a diagnostic tool, not a goal. 60% meaningful coverage beats 95% testing implementation details.

Automate everything. Manual processes fail. Automated gates are consistent, fast, and free developers to build.

When agents design quality infrastructure, they should:

• Default to Lefthook for git hooks (not Husky)
• Configure parallel execution for speed
• Set up pre-commit for fast checks (staged files only)
• Set up pre-push for comprehensive validation
• Include GitHub Actions with matrix testing
• Enforce branch protection on main/production branches
• Use Codecov or similar for coverage tracking
• Focus on testing behavior, not implementation