CI 缓存、并行任务和失败产物

🔄 好的 CI 配置能将流水线执行时间从 10 分钟压到 2 分钟。缓存、并行化和失败产物是三大丝。

构建缓存

Node modules 缓存

# GitHub Actions 示例
- name: Cache node modules
  uses: actions/cache@v4
  with:
    path: ~/.npm  # 或 node_modules
    key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
    restore-keys: |
      ${{ runner.os }}-node-

Vite/Turborepo 缓存

- name: Cache Vite build
  uses: actions/cache@v4
  with:
    path: |
      node_modules/.vite
      .turbo
    key: ${{ runner.os }}-vite-${{ hashFiles('src/**') }}

缓存命中率技巧

• key 精确匹配，restore-keys 作为备选匹配
• 包含易变内容的文件哈希（如 package-lock.json）
• 不同 平台（OS）必须分开缓存 key

---

任务并行化

jobs:
  test:
    strategy:
      matrix:
        node-version: [18, 20, 22]
      max-parallel: 3
      fail-fast: false  # 一个失败不停止其他
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
      - run: npm ci
      - run: npm test

任务依赖与并行

jobs:
  lint:    runs-on: ubuntu-latest
  test:    runs-on: ubuntu-latest
  build:   needs: [lint, test]  # 并行 lint + test 后才 build
  deploy:  needs: [build]       # build 完成才 deploy

---

失败产物

- name: Run tests
  run: npm test

- name: Upload test results on failure
  if: failure()  # 只在失败时上传
  uses: actions/upload-artifact@v4
  with:
    name: test-results-${{ github.run_id }}
    path: |
      coverage/
      playwright-report/
      test-results/
    retention-days: 7  # 保留 7 天

- name: Upload Playwright trace on failure
  if: failure()
  uses: actions/upload-artifact@v4
  with:
    name: playwright-traces
    path: test-results/**/*.zip

---

常用 CI 模式

完整前端 CI 流水线

name: CI

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

jobs:
  quality:
    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 type-check
      - run: npm run lint
      - run: npm run test:unit -- --coverage
      
  e2e:
    runs-on: ubuntu-latest
    needs: quality
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: 20, cache: 'npm' }
      - run: npm ci
      - run: npx playwright install --with-deps chromium
      - run: npm run test:e2e
      - if: failure()
        uses: actions/upload-artifact@v4
        with:
          name: playwright-report
          path: playwright-report/

---

常见误区

• 每次都重新安装 node_modules 而没有缓存，流水线正常 CI 5+ 分钟
• 所有任务串行执行，没有利用 needs 并行化
• 失败时没有保留产物，调试 CI 失败时无屏可查