After a pull request (PR) is created, how the checks are performed in github

After a pull request (PR) is created on GitHub, checks or automated workflows can be triggered to verify the changes and ensure they meet certain criteria before merging. Here’s how this process generally works:

Automated Checks and Workflows

1. CI/CD Integration:

   • GitHub integrates with Continuous Integration (CI) services like GitHub Actions, Travis CI, CircleCI, Jenkins, etc.
   • These services are configured to automatically run tests, linters, code quality checks, and any other defined workflows whenever a new commit or PR is created.

2. Triggering Checks:

   • When you create a pull request, GitHub automatically triggers configured workflows or checks associated with the repository.
   • Checks can also be manually triggered by commenting with specific keywords or using GitHub’s interface.

3. GitHub Actions Example:

   • If GitHub Actions is set up for the repository, workflows defined in .github/workflows/ are triggered based on events such as pull_request or push.
   • For example, a workflow might include steps to build the project, run tests, check code style, and deploy artifacts.

   name: CI
   
   on:
     pull_request:
       branches:
         - main
       paths:
         - '**/*.js'
         - '**/*.java'
   
   jobs:
     build:
       runs-on: ubuntu-latest
       steps:
         - name: Checkout code
           uses: actions/checkout@v2
   
         - name: Set up JDK 11
           uses: actions/setup-java@v2
           with:
             java-version: '11'
   
         - name: Build and Test
           run: |
             mvn clean install
             npm test
   

4. Checking Status:

   • After checks are triggered, GitHub displays the status of each check on the PR page.
   • You can see if checks are pending, passing, or failing. This helps maintainers and contributors understand the readiness of the changes.

5. Review and Merge:

   • Maintainers and collaborators review the PR, including the results of automated checks.
   • They may request changes or approve the PR for merging based on the outcomes of the checks.

Best Practices

• Configure Comprehensive Checks: Include tests, code style checks, and other relevant workflows in your CI/CD pipeline to ensure comprehensive validation of changes.
• Fast Feedback Loop: Configure checks to run quickly to provide prompt feedback to contributors.
• Use Status Checks: Leverage GitHub’s status checks API to programmatically check the status of checks before merging.