Workflows e Eventos

O que é GitHub Actions?

GitHub Actions automatiza builds, testes e deploys diretamente do GitHub. Workflows são arquivos YAML em .github/workflows/.

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

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]
  workflow_dispatch:      # execução manual

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: echo "Hello, Actions!"

Estrutura do Workflow

name: Deploy
run-name: "Deploy ${{ github.ref_name }} by @${{ github.actor }}"

on:
  push:
    tags:
      - 'v*'

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

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

  test:
    needs: [lint]
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: [18, 20, 22]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
      - run: npm ci && npm test

  build:
    needs: [test]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: npm ci && npm run build
      - uses: actions/upload-artifact@v4
        with:
          name: build
          path: dist/

  deploy:
    needs: [build]
    runs-on: ubuntu-latest
    environment: production
    concurrency: production
    steps:
      - uses: actions/download-artifact@v4
        with:
          name: build
          path: dist
      - run: echo "Deploying..."

Eventos Comuns

on:
  push:                                    # push em qualquer branch
    branches:
      - main
      - 'stable/*'
    tags:
      - 'v*'
    paths:
      - 'src/**'
      - '!docs/**'

  pull_request:                            # PR aberto/sincronizado
    types: [opened, synchronize, reopened]

  schedule:                                # cron
    - cron: '0 2 * * 1'                   # toda segunda 2h

  workflow_run:                            # após outro workflow
    workflows: ["CI"]
    types:
      - completed

  repository_dispatch:                     # API externa
    types: [deploy-prod]

  release:
    types: [published]

Matrix Builds

jobs:
  test:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macos-latest]
        node: [18, 20, 22]
        include:
          - os: ubuntu-latest
            node: 20
            coverage: true
        exclude:
          - os: macos-latest
            node: 18
      fail-fast: false      # continua se uma matrix falhar
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node }}
      - run: npm ci && npm test
      - if: matrix.coverage
        run: npm run coverage

Contexts e Expressões

jobs:
  context-demo:
    runs-on: ubuntu-latest
    steps:
      - run: |
          echo "Event: ${{ github.event_name }}"
          echo "Branch: ${{ github.ref_name }}"
          echo "SHA: ${{ github.sha }}"
          echo "Actor: ${{ github.actor }}"
          echo "Repo: ${{ github.repository }}"
        shell: bash

      - if: github.event_name == 'pull_request'
        run: echo "PR #${{ github.event.number }}"

      - if: startsWith(github.ref, 'refs/tags/v')
        run: echo "Release ${{ github.ref_name }}"

      - if: failure()
        run: echo "Passo anterior falhou"

Workflows = eventos → jobs (paralelos) → steps (sequenciais). Matrix testa múltiplas configurações. Contexts (github., env., secrets.*) fornecem dados dinâmicos.