Daniele Cammarata

GitHub Actions is a powerful tool that allows you to automate, customize, and execute software development workflows right in your GitHub repository. One of the most common use cases is automating workflows for pull requests. In this blog post, we’ll explore how to set up GitHub Actions to automate various tasks when a pull request is opened, updated, or merged.

What is GitHub Actions?

GitHub Actions is a CI/CD (Continuous Integration and Continuous Deployment) service provided by GitHub. It allows you to create custom workflows that automatically run in response to events in your repository. These workflows are defined using YAML syntax and can include a variety of actions, such as running tests, deploying code, and more.

Why Automate Pull Request Workflows?

Automating workflows for pull requests can significantly improve your development process by:

Ensuring code quality through automated testing.
Enforcing coding standards with linters.
Automatically building and deploying preview environments.
Providing immediate feedback to contributors.
Reducing manual steps in the review process.

Setting Up GitHub Actions for Pull Requests

Step 1: Create a Workflow File

To create a workflow, you’ll need to add a YAML file in the .github/workflows directory of your repository. For example, create a file named pull_request.yml.

Step 2: Define the Workflow

Here’s an example of a simple workflow that runs tests and lint checks when a pull request is opened or updated:

name: Pull Request Workflow

on:
  pull_request:
    types: [opened, synchronize]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Set up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 18

      - name: Install dependencies
        run: npm install

      - name: Run tests
        run: npm test

      - name: Run linter
        run: npm run lint

Step 3: Commit and Push the Workflow

After defining your workflow, commit and push the pull_request.yml file to your repository:

git add .github/workflows/pull_request.yml
git commit -m "Add pull request workflow"
git push origin main

Step 4: Customize the Workflow

You can customize the workflow to suit your project’s needs. Here are a few common actions you might want to include:

Running Code Coverage

To measure code coverage, you can integrate tools like jest with coverage reporting:

- name: Run tests with coverage
  run: npm test -- --coverage

Deploying Preview Environments

You can deploy a preview environment to services like Vercel or Netlify:

- name: Deploy to Vercel
  uses: amondnet/vercel-action@v25
  with:
    vercel-token: ${{ secrets.VERCEL_TOKEN }}
    github-token: ${{ secrets.GITHUB_TOKEN }}
    working-directory: .
    vercel-org-id: ${{ secrets.ORG_ID}}
    vercel-project-id: ${{ secrets.PROJECT_ID}}

Sending Notifications

You can send notifications to Slack or other communication tools:

- name: Notify Slack
  uses: slackapi/slack-github-action@v1.26.0
  with:
    slack-message: "A new pull request has been opened!"
    channel-id: ${{ secrets.SLACK_CHANNEL_ID }}
  env:
    SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}

Best Practices for Pull Request Workflows

Run Tests Early: Ensure that tests run as soon as a pull request is opened to catch issues early.
Use Secrets for Sensitive Data: Store sensitive information, like API keys, in GitHub Secrets.
Limit Workflow Scope: Only run necessary jobs for pull requests to save time and resources.
Provide Feedback: Use GitHub Checks to provide feedback directly on the pull request.

Conclusion

GitHub Actions provides a flexible and powerful way to automate workflows for pull requests. By setting up automated tests, linting, deployments, and notifications, you can improve your development process and ensure that your code meets the required standards before it is merged. Start experimenting with GitHub Actions today and see how it can enhance your project’s workflow!

GitHub Actions - Pull Request Workflows