Pull Request
A proposal to merge code changes from one branch into another, enabling code review, discussion, and automated testing before integration.
Detailed Explanation
A pull request (PR) is the collaboration hub of modern development. When a developer finishes work on a branch, they open a PR requesting that their changes be merged. The PR shows the diff (changes), enables inline comments and discussion, runs automated checks (CI), and requires approval before merging.
PRs are where code quality is enforced, knowledge is shared, and bugs are caught before they reach production. Best practices include keeping PRs small (under 400 lines), writing descriptive titles and descriptions, linking to issues, requesting specific reviewers, and addressing all feedback before merging.
Why It Matters
Pull requests are the primary mechanism for code quality, knowledge sharing, and team collaboration in modern development.
Real-World Example
A developer opens a PR titled "Add email validation to registration form" with a description of what changed and why. Two reviewers leave comments suggesting improvements. The developer makes changes, reviewers approve, and the PR is merged.
When to Use
For every code change that affects shared code. Even solo developers benefit from PRs for the CI checks and documentation of changes.
Advantages
- Enables code review before integration
- Runs automated tests and checks
- Creates a discussion forum for changes
- Provides a record of why changes were made
- Enables branch protection rules
Disadvantages
- Adds overhead for small changes
- Can become a bottleneck if reviews are slow
- Large PRs are hard to review thoroughly
- Depends on team discipline for quality
- Can create merge queue bottlenecks
Related Terms
Frequently Asked Questions
How big should a pull request be?
Aim for under 400 lines of changes. Smaller PRs are reviewed faster, have fewer bugs, and are easier to understand. Break large features into smaller, incremental PRs.
What should I include in a PR description?
Include what changed, why it changed, how to test it, screenshots for UI changes, and links to related issues. A good description helps reviewers understand context and review faster.
What is a draft pull request?
A draft PR signals that the work is in progress and not ready for review. It disables merge and review requests. Use it to share early work for feedback without requesting formal review.
How do I handle review feedback?
Address each comment with a code change or explanation. Use "Resolve conversation" for addressed items. Push additional commits rather than amending, so reviewers can see what changed since their last review.
Can I merge my own PR?
In most team workflows, no—you need someone else to review and approve. For personal projects or emergencies, you can merge your own PR, but always run CI checks first.