1. Introduction

In this tutorial, we aim to educate our readers on the concept and implementation of branch protection rules in GitHub. By the end of this tutorial, you'll have a firm understanding of how to set up these rules, which can prevent unauthorized modifications to your code, thus helping to maintain the integrity and security of your projects.

What You Will Learn

• What are Branch Protection Rules?
• How to create Branch Protection Rules?
• How to enforce these rules?

Prerequisites

• Basic knowledge of Git and GitHub
• A GitHub account

2. Step-by-Step Guide

Branch protection rules in GitHub allow repository administrators to define which actions users can perform on a specific branch. For instance, rules can be set to prevent force pushes (which can overwrite code on a branch), prevent branches from being deleted, or require pull request reviews before merging.

Creating Branch Protection Rules

1. Navigate to your GitHub repository, go to the 'Settings' tab, and click on 'Branches'.
2. Click on the 'Add rule' button next to 'Branch protection rules'.
3. In the 'Branch name pattern' field, enter the name of the branch you want to protect.
4. Under 'Protect matching branches', you'll find several options. Check the ones you want to enforce:
5. Require pull request reviews before merging: This requires approval before changes can be merged.
6. Require status checks to pass before merging: This ensures all required CI checks are successful before merging is allowed.
7. Include administrators: This applies the rules to administrators as well.
8. Click on 'Create' to save your settings.

3. Code Examples

Since branch protection rules are a feature of GitHub's UI and not a coding concept, there are no traditional 'code examples' for this topic. However, here's a practical example of setting up a rule:

1. Branch name pattern: master
2. Options selected:
3. [x] Require pull request reviews before merging
4. [x] Include administrators

This rule means that any changes to the master branch must be made via a pull request, which requires approval before merging. This rule also applies to administrators.

4. Summary

In this tutorial, we learned about branch protection rules in GitHub, how to create them, and what they can do. These rules help maintain the integrity and security of your codebase by preventing unauthorized or potentially harmful modifications.

Next Steps

• Explore more about GitHub features like Actions, Projects
• Learn how to handle merge conflicts in GitHub
• Dive deeper into more advanced Git topics like rebasing, cherry-pick, etc.

Additional Resources

• GitHub Docs
• Pro Git book

5. Practice Exercises

1. Exercise 1: Create a repository and set up a branch protection rule for the master branch that requires pull request reviews before merging.
2. Exercise 2: Adjust your branch protection rule to also require status checks to pass before merging.
3. Exercise 3: Create a new branch, make a change, and attempt to merge it into master. What happens?

Solutions

1. Solution to Exercise 1: You should have a repository with a branch protection rule on master that requires pull request reviews.
2. Solution to Exercise 2: Your rule should now also require status checks to pass before changes to master can be merged.
3. Solution to Exercise 3: GitHub should prevent you from directly merging the branch into master without a pull request review. This shows that your branch protection rule is working.