Branch protection rules in Git - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary purpose of branch protection rules?

Branch protection rules in Git repositories help teams maintain code quality and control. What is the main goal of these rules?

A To allow anyone to force push changes anytime

B To automatically merge all pull requests without review

C To delete branches after every commit

D To prevent direct pushes to important branches without review or checks

💡 Hint

Think about how teams avoid mistakes on main branches.

Branch protection rules stop direct pushes or force pushes to critical branches, requiring reviews or passing tests first.

💻 Command Output

intermediate

What is the output of listing branch protection rules with GitHub CLI?

Using GitHub CLI, you run the command to list branch protection rules for the 'main' branch. What output do you expect?

Git

gh api repos/owner/repo/branches/main/protection

A {"required_status_checks":{"strict":true,"contexts":["ci/test"]},"enforce_admins":true,"required_pull_request_reviews":{"required_approving_review_count":2}}

B Error: branch 'main' not found

C Permission denied: cannot access branch protection

D No protection rules set for branch 'main'

💡 Hint

Think about what a successful API call returns.

The command returns JSON showing the protection rules like required status checks and review counts.

❓ Configuration

advanced

Which YAML snippet correctly enforces branch protection in GitHub Actions workflow?

You want to enforce that pull requests to 'main' must pass tests before merging. Which YAML snippet correctly configures this?

A

on:
  pull_request:
    branches-ignore:
      - main
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Run tests here"

B

on:
  push:
    branches:
      - main
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Run tests here"

C

on:
  pull_request:
    branches:
      - main
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: echo "Run tests here"

D

on:
  pull_request:
    branches:
      - develop
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Run tests here"

💡 Hint

Which event triggers the workflow for pull requests targeting 'main'?

Option C triggers on pull requests to 'main', running tests before merging. Others either trigger on push or wrong branches.

❓ Troubleshoot

advanced

Why does a force push to a protected branch fail?

You try to force push changes to a protected branch but get an error. What is the most likely reason?

A Your local Git client is outdated and cannot push

B Branch protection rules disallow force pushes to prevent overwriting history

C The remote repository is full and cannot accept new commits

D You forgot to pull the latest changes before pushing

💡 Hint

Think about why force pushing might be blocked on important branches.

Force pushes rewrite history and can cause data loss, so branch protection rules block them on protected branches.

🔀 Workflow

expert

In what order should these steps be configured to enforce branch protection with required reviews and status checks?

Arrange the steps to correctly set up branch protection rules that require pull request reviews and passing status checks before merging.

A 3,2,1,4

B 2,3,1,4

C 1,3,2,4

D 3,1,2,4

💡 Hint

Think about selecting the branch first, then defining checks and reviews, then saving.

You first select the branch, then specify required status checks, enable review requirements, and finally save the settings.

Practice

1. What is the main purpose of branch protection rules in Git repositories?

easy

A. To prevent direct changes to important branches without review or checks

B. To delete branches automatically after merging

C. To speed up the cloning process of the repository

D. To allow anyone to push changes without restrictions

Solution

1. Step 1: Understand branch protection rules

   Branch protection rules are designed to keep important branches safe by enforcing rules like requiring reviews or passing tests before changes can be merged.

2. Step 2: Identify the correct purpose

   Options A, B, and D describe unrelated or incorrect behaviors. Only To prevent direct changes to important branches without review or checks correctly describes the purpose of branch protection rules.

3. Final Answer:

   To prevent direct changes to important branches without review or checks -> Option A

4. Quick Check:

   Branch protection = prevent unsafe direct changes [OK]

Hint: Branch protection means safe branches, no direct unsafe changes [OK]

Common Mistakes:

• Thinking branch protection deletes branches
• Confusing branch protection with performance features
• Assuming branch protection allows unrestricted pushes

2. Which of the following is the correct way to enable branch protection for the main branch on GitHub via the web interface?

easy

A. Create a file named branch-protect.yml in the root directory

B. Run git protect main in the terminal

C. Go to Settings > Branches > Add rule > Specify 'main' > Select protections > Save

D. Push a branch named protected/main to enable protection

Solution

1. Step 1: Know how to set branch protection on GitHub

   Branch protection rules are set in the repository's Settings under Branches by adding a rule for the branch name and selecting protections.

2. Step 2: Evaluate options

   Go to Settings > Branches > Add rule > Specify 'main' > Select protections > Save describes the correct web interface steps. Options B, C, and D are invalid commands or methods not supported by GitHub.

3. Final Answer:

   Go to Settings > Branches > Add rule > Specify 'main' > Select protections > Save -> Option C

4. Quick Check:

   GitHub branch protection set via Settings > Branches [OK]

Hint: Branch protection is set in repo Settings under Branches [OK]

Common Mistakes:

• Trying to use git CLI commands that don't exist
• Assuming config files control branch protection
• Thinking branch protection is automatic on branch creation

3. Given this branch protection rule requiring pull request reviews before merging, what happens if a user tries to push directly to the protected branch?

Rule: Require pull request reviews before merging

medium

A. The push is rejected with an error message

B. The push succeeds without any checks

C. The branch is automatically deleted

D. The push creates a new branch instead

Solution

1. Step 1: Understand the rule effect

   Requiring pull request reviews means direct pushes to the branch are blocked to enforce code review before changes.

2. Step 2: Predict the push behavior

   Because direct pushes are blocked, the push attempt will be rejected with an error message. Options A, B, and C are incorrect behaviors.

3. Final Answer:

   The push is rejected with an error message -> Option A

4. Quick Check:

   Require review blocks direct push = push rejected [OK]

Hint: Require review means no direct push allowed [OK]

Common Mistakes:

• Assuming push silently creates new branch
• Thinking push succeeds without review
• Believing branch gets deleted on push

4. A developer sets a branch protection rule to require status checks before merging, but merges are still allowed without passing checks. What is the likely cause?

medium

A. The developer forgot to push the branch

B. The status checks are not selected/enabled in the branch protection settings

C. The repository has no branches

D. The branch protection rules only apply to forks

Solution

1. Step 1: Analyze the protection rule setup

   Requiring status checks means you must select which checks must pass in the branch protection settings.

2. Step 2: Identify why merges bypass checks

   If merges happen without passing checks, it usually means the required checks were not properly selected or enabled in the settings.

3. Final Answer:

   The status checks are not selected/enabled in the branch protection settings -> Option B

4. Quick Check:

   Missing selected checks = merges bypass checks [OK]

Hint: Enable and select status checks in protection settings [OK]

Common Mistakes:

• Assuming branch protection applies only to forks
• Thinking pushing branch affects protection
• Ignoring the need to select specific status checks

5. You want to protect the release branch so that only team leads can push directly, and everyone else must use pull requests with reviews. Which branch protection settings should you apply?

hard

A. Require status checks but allow anyone to push directly

B. Enable 'Require signed commits' only

C. Disable all protections and trust the team

D. Enable 'Restrict who can push' to team leads and require pull request reviews for others

Solution

1. Step 1: Understand the requirement

   The goal is to allow only team leads to push directly and force others to use pull requests with reviews.

2. Step 2: Choose correct settings

   Enabling 'Restrict who can push' to team leads limits direct pushes to them. Requiring pull request reviews ensures others must use PRs. Options B, C, and D do not meet both conditions.

3. Final Answer:

   Enable 'Restrict who can push' to team leads and require pull request reviews for others -> Option D

4. Quick Check:

   Restrict push + require reviews = controlled direct push [OK]

Hint: Restrict push to leads + require reviews for others [OK]

Common Mistakes:

• Only requiring signed commits without push restrictions
• Disabling protections and trusting team
• Allowing anyone to push directly with status checks only