Technical reference

GitHub Actions Cheatsheet

Automate tests, builds, and deployments

Must Know

yaml

Node CI

name: CI
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: npm
      - run: npm ci
      - run: npm test
      - run: npm run build

yaml

Events and Filters

on:
  push:
    branches: [main]
  pull_request:
    paths:
      - 'src/**'
      - 'package-lock.json'

Important Patterns

yaml

Least-Permission Token

Set explicit permissions at workflow or job level.

permissions:
  contents: read
  pull-requests: write

yaml

Concurrency

Avoid overlapping deployments for the same target.

concurrency:
  group: deploy-${{ github.ref }}
  cancel-in-progress: true

Useful Recipes

yaml

Matrix Tests

strategy:
  matrix:
    node: [20, 22]
steps:
  - uses: actions/setup-node@v4
    with: { node-version: '${{ matrix.node }}' }

yaml

Artifacts

Store reports and build outputs with short retention.

- uses: actions/upload-artifact@v4
  with:
    name: test-report
    path: reports/
    retention-days: 7

Pitfalls & Production

Supply-Chain Safety

Workflow changes can execute privileged code.

pin third-party actions to a commit SHA
protect deployment environments
use OIDC instead of long-lived cloud keys

Secrets

Environment approvals can protect production secrets.

${{ secrets.API_TOKEN }}
# Never print secrets or pass them to untrusted PR code.