GitHub Actions

GitHub Actions automate workflows directly in your repository.

Basic Workflow

Create a file at .github/workflows/ci.yml:

name: CI

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

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm install
      - run: npm test

Key Concepts

Concept	Description
Workflow	Automated process defined in YAML
Event	Trigger that starts a workflow (push, pull_request, schedule)
Job	Set of steps that run on the same runner
Step	Individual task - runs a command or an action
Action	Reusable unit of code (actions/checkout@v4)

Workflow Diagram

graph LR
    A[Push to main] --> B[Checkout code]
    B --> C[Install deps]
    C --> D[Run tests]
    D --> E{Pass?}
    E -->|Yes| F[Deploy]
    E -->|No| G[Notify]

Useful Actions

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

# Upload artifacts
- uses: actions/upload-artifact@v4
  with:
    name: build
    path: dist/

Browse the GitHub Marketplace for thousands of community actions.