Why Code review in pull requests in Git? - Purpose & Use Cases

The Big Idea

What if you could catch mistakes early and make teamwork feel easy and fun?

The Scenario

Imagine you and your friends are writing a story together by passing a notebook around. Each person writes a part, but you have to wait until the notebook comes back to check if the story makes sense and fix mistakes.

The Problem

This slow back-and-forth makes it easy to miss errors, causes confusion, and wastes time because you can't see changes clearly or discuss them easily.

The Solution

Pull requests let you share your changes online where everyone can see, comment, and suggest improvements before merging. This makes teamwork smooth, clear, and fast.

Before vs After

✗ Before

Email code files back and forth for review

✓ After

Create a pull request on GitHub for team review and discussion

What It Enables

It enables clear, organized, and collaborative code improvements that everyone can track and agree on before changes go live.

Real Life Example

A developer finishes a new feature and opens a pull request so teammates can review the code, suggest fixes, and approve it before adding it to the main project.

Key Takeaways

Manual code sharing is slow and confusing.

Pull requests create a clear space for feedback and teamwork.

This improves code quality and speeds up collaboration.

Practice

1. What is the main purpose of a pull request in Git?

easy

A. To review and discuss code changes before merging

B. To delete a branch from the repository

C. To create a new repository

D. To reset the main branch to a previous commit

Solution

1. Step 1: Understand what a pull request does

   A pull request is used to propose code changes and get feedback before merging.

2. Step 2: Identify the main purpose

   It allows team members to review, discuss, and approve changes to keep code quality high.

3. Final Answer:

   To review and discuss code changes before merging -> Option A

4. Quick Check:

   Pull request = code review and discussion [OK]

Hint: Pull requests are for reviewing code before merging [OK]

Common Mistakes:

• Confusing pull requests with branch deletion
• Thinking pull requests create repositories
• Believing pull requests reset branches

2. Which Git command is used to push a new branch to the remote repository to start a pull request?

easy

A. git push origin main

B. git merge feature-branch

C. git pull origin feature-branch

D. git push origin feature-branch

Solution

1. Step 1: Identify the command to push a branch

   To push a new branch named 'feature-branch' to remote, use 'git push origin feature-branch'.

2. Step 2: Understand other options

   'git push origin main' pushes the main branch, 'git pull' fetches changes, and 'git merge' combines branches locally.

3. Final Answer:

   git push origin feature-branch -> Option D

4. Quick Check:

   Push new branch = git push origin branch-name [OK]

Hint: Push your feature branch with git push origin branch-name [OK]

Common Mistakes:

• Using git push origin main instead of feature branch
• Confusing git pull with git push
• Trying to merge before pushing the branch

3. Given this sequence of commands, what is the output of git status after step 4?

1. git checkout -b feature
2. touch newfile.txt
3. git add newfile.txt
4. git status

medium

A. On branch feature
Changes to be committed:
(new file: newfile.txt)

B. On branch feature
nothing to commit, working tree clean

C. On branch main
Changes to be committed:
(new file: newfile.txt)

D. fatal: not a git repository

Solution

1. Step 1: Analyze branch and file status

   After 'git checkout -b feature', you are on 'feature' branch. 'touch newfile.txt' creates a new file. 'git add newfile.txt' stages it.

2. Step 2: Understand git status output

   'git status' shows staged changes. Since newfile.txt is added, it appears under 'Changes to be committed' on branch 'feature'.

3. Final Answer:

   On branch feature Changes to be committed: (new file: newfile.txt) -> Option A

4. Quick Check:

   Added file staged = git status shows it [OK]

Hint: Staged files show under 'Changes to be committed' in git status [OK]

Common Mistakes:

• Assuming branch is still main
• Thinking staging clears changes
• Confusing untracked with staged files

4. You created a pull request but reviewers say your branch is behind main and has conflicts. What should you do to fix this?

medium

A. Delete your branch and create a new one

B. Force push your branch without updating

C. Merge main into your branch locally and resolve conflicts

D. Close the pull request and push directly to main

Solution

1. Step 1: Understand the conflict cause

   Your branch is behind main, so changes in main conflict with your branch.

2. Step 2: Fix conflicts by merging main

   Merge main into your branch locally using 'git merge main', resolve conflicts, then push updates to update the pull request.

3. Final Answer:

   Merge main into your branch locally and resolve conflicts -> Option C

4. Quick Check:

   Fix conflicts = merge main and resolve [OK]

Hint: Merge main into your branch to fix conflicts before pushing [OK]

Common Mistakes:

• Force pushing without resolving conflicts
• Deleting branch unnecessarily
• Pushing directly to main ignoring review

5. You want to ensure that every pull request is reviewed by at least two team members before merging. Which GitHub feature should you configure?

hard

A. Enable auto-merge on pull requests

B. Branch protection rules with required reviews

C. Set default branch to feature branch

D. Use git stash before pushing

Solution

1. Step 1: Identify the feature for enforcing reviews

   GitHub branch protection rules allow setting requirements like minimum number of reviewers before merging.

2. Step 2: Understand other options

   Auto-merge merges without review, changing default branch doesn't enforce reviews, and git stash is unrelated to pull requests.

3. Final Answer:

   Branch protection rules with required reviews -> Option B

4. Quick Check:

   Require reviews = branch protection rules [OK]

Hint: Use branch protection rules to require reviews before merge [OK]

Common Mistakes:

• Confusing auto-merge with review enforcement
• Changing default branch instead of protection rules
• Using git stash unrelated to reviews