Add GitHub Actions CI

Description

Your team has been manually testing code before merging pull requests. This is slow, error-prone, and doesn't scale. You need to set up automated testing that runs on every push.

Task

Add a GitHub Actions workflow that runs tests on every push.

Requirements:

• Trigger on push and pull request events
• Run tests for the application
• Report test results
• Fail the build if tests fail

Target

• ✅ Workflow runs automatically on push
• ✅ All tests execute successfully
• ✅ Clear pass/fail status in GitHub UI
• ✅ Runs in under 2 minutes

Sample App

Simple Node.js App (app.test.js)

// app.js
function add(a, b) {
  return a + b;
}

function multiply(a, b) {
  return a * b;
}

module.exports = { add, multiply };

// app.test.js
const { add, multiply } = require('./app');

test('adds 1 + 2 to equal 3', () => {
  expect(add(1, 2)).toBe(3);
});

test('multiplies 2 * 3 to equal 6', () => {
  expect(multiply(2, 3)).toBe(6);
});

package.json

{
  "name": "advent-ci",
  "version": "1.0.0",
  "scripts": {
    "test": "jest"
  },
  "devDependencies": {
    "jest": "^29.0.0"
  }
}

Result

After setup, you'll see:

• ✅ Green checkmark on passing commits
• ✅ Red X on failing tests
• ✅ Test results in PR checks
• ✅ Automatic testing on every push

GitHub UI Shows:

✓ CI / Run Tests (22.x) - 1m 23s
✓ CI / Run Tests (24.x) - 1m 19s
✓ CI / Lint Code - 45s

Validation

Test the Workflow

# Clone your repository
git clone <your-repo>
cd <your-repo>

# Make a change
echo "test('example', () => expect(true).toBe(true));" >> app.test.js

# Commit and push
git add .
git commit -m "test: add example test"
git push origin main

# Watch workflow run in GitHub Actions tab

Check Workflow Status

# Using GitHub CLI
gh run list --workflow=ci.yml

# View latest run
gh run view --log

Advanced Features

Add Code Coverage

- name: Generate coverage
  run: npm test -- --coverage

- name: Upload to Codecov
  uses: codecov/codecov-action@v7
  with:
    token: ${{ secrets.CODECOV_TOKEN }}

Add Build Caching

- name: Cache build output
  uses: actions/cache@v6
  with:
    path: |
      ~/.npm
      node_modules
    key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}

Conditional Steps

- name: Deploy
  if: github.ref == 'refs/heads/main' && success()
  run: npm run deploy

Links

• GitHub Actions Documentation
• Workflow Syntax
• GitHub Actions Marketplace
• actions/checkout
• actions/setup-node

Share Your Success

Got your CI pipeline running? Share it!

Tag @thedevopsdaily on X with:

• Screenshot of your passing workflow
• Number of tests running
• Workflow execution time

Use hashtags: #AdventOfDevOps #GitHubActions #CI #Day3