Automated Test Run on Pull Request Setup

Setting Up Automated Test Execution on Pull Request

Auto-run tests on PR—basic protection against regressions. A developer cannot merge code that breaks existing functionality. This is not a replacement for code review, but its supplement: reviewer focuses on logic, not catching obvious bugs.

Pipeline Structure

A well-structured pipeline is split into parallel jobs with fail-fast strategy:

# .github/workflows/pr.yml
name: PR Tests
on:
  pull_request:
    branches: [main, develop]

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true  # Cancel old runs on new push

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: 20, cache: npm }
      - run: npm ci
      - run: npm run lint && npm run type-check

  unit:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: 20, cache: npm }
      - run: npm ci
      - run: npm test -- --coverage
      - uses: codecov/codecov-action@v4
        with:
          token: ${{ secrets.CODECOV_TOKEN }}

  integration:
    runs-on: ubuntu-latest
    services:
      postgres:
        image: postgres:16
        env:
          POSTGRES_DB: testdb
          POSTGRES_PASSWORD: test
        options: >-
          --health-cmd pg_isready
          --health-interval 5s
          --health-timeout 5s
          --health-retries 5
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: 20, cache: npm }
      - run: npm ci
      - run: npm run test:integration
        env:
          DATABASE_URL: postgresql://postgres:test@localhost:5432/testdb

Dependency Caching

# Cache node_modules by package-lock.json
- uses: actions/setup-node@v4
  with:
    node-version: 20
    cache: npm  # Built-in cache in actions/setup-node

# Or explicit via actions/cache
- uses: actions/cache@v4
  with:
    path: ~/.npm
    key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}

Without cache npm ci on cold runner—60–90 seconds. With cache—5–10 seconds.

Test Matrix

If the application must work on multiple versions of Node.js or PHP:

strategy:
  matrix:
    node-version: [18, 20, 22]
  fail-fast: false  # Run all versions even if one fails

PHP / Laravel

- name: Run PHPUnit
  run: php artisan test --parallel --coverage-clover=coverage.xml
  env:
    DB_CONNECTION: pgsql
    DB_DATABASE: testing

- name: Upload coverage
  uses: codecov/codecov-action@v4
  with:
    files: coverage.xml

--parallel runs tests in parallel via brianium/paratest. On 200+ tests speeds up 3–4 times.

Status Checks and Branch Protection

In GitHub Settings → Branches → Branch protection rules add required status checks: lint, unit, integration. Merge to main without passing these checks is impossible.

Speed Optimization

• Path filtering—run tests only when relevant files change
• Test splitting—distribute tests across multiple runners (GitHub Actions matrix)
• Only changed modules—Jest --changedSince, pytest --testpaths

Goal: pipeline fits in 5 minutes. Slower—developers start ignoring it.

Timeline

Setting up basic pipeline with unit and integration tests for Node.js or PHP project—1–2 days. Setting up coverage reports and badge in README—0.5 days.