Best practices for refactoring pull requests

Refactoring pull requests (PRs) involves improving the structure, readability, or efficiency of code without changing its external behavior. While refactoring is helpful for maintaining clean and scalable codebases, doing so within PRs requires attention to clarity, scope, and collaboration. Below are best practices to guide you when refactoring code in pull requests, including tips for GitHub workflows and how to use the Graphite PR inbox for efficiency.

Keep refactoring changes separate from feature work

A common pitfall is mixing refactoring with new feature development or bug fixes. This makes reviews harder because it’s difficult to identify which changes relate to the feature and which are purely refactors. Instead:

• Create separate PRs: Isolate refactoring work from functional changes. For example, if you are cleaning up helper functions while adding a new API endpoint, submit one PR for the endpoint and another for refactoring the helpers.
• Use branches effectively: Maintain branches dedicated to refactoring tasks. Tools like Graphite's PR inbox can help you organize and track these branches separately under custom sections, such as "Needs your review" or "Waiting for review".

For example's sake, suppose you're working on a feature to add user profiles. You spot redundant database query logic in unrelated code, so you need to:

• Create a refactor-db-queries branch.
• Submit a PR titled "Refactor redundant database queries."
• Continue feature work in a separate branch, ensuring the two are reviewed independently.

Break down large refactoring efforts

Refactoring significant parts of a codebase can result in large PRs that are difficult to review and more prone to merge conflicts. Instead:

• Chunk your changes: Break down large refactors into smaller, logical steps. For instance, refactor one module or class per PR.
• Stack pull requests: Create a stack of PRs, which is supported by Graphite, to organize dependent PRs. This allows reviewers to focus on incremental changes rather than a massive overhaul.

For example, when modularizing a monolithic class, you might create the following stacked PRs:

1. Extract a utility function into a helper module.
2. Move related methods to a new service class.
3. Update references across the codebase.

Stacking these PRs ensures clarity and reduces review fatigue.

Communicate the intent of the refactor

Refactoring often involves subjective decisions about code organization. Clear communication helps reviewers understand the motivation behind your changes. Use descriptive PR titles and summaries to explain:

• Why the refactor is needed: For example, "Improves testability by breaking down a monolithic function."
• What was changed: Summarize the areas of the code affected and how they were improved.
• Risks and mitigations: Highlight any potential issues, such as changes that could unintentionally break dependencies.

Graphite's PR inbox supports detailed PR descriptions, making it easier for reviewers to prioritize and focus on high-impact changes. Graphite also leverages AI to generate detail-oriented PR descriptions for you.

Write tests for refactored code

Even though refactoring doesn’t alter external behavior, subtle changes can introduce bugs. To minimize this risk:

• Add or update tests: Ensure that unit and integration tests cover all refactored code paths.
• Run automated checks: Leverage continuous integration tools like GitHub Actions to validate tests against your PR.

For exmaple, if refactoring involves simplifying a complex conditional, write unit tests for edge cases that might behave differently post-refactor.

Review and iterate collaboratively

Refactoring is often subjective. You can encourage unified collaboration by:

• Using inline comments: When submitting your PR, leave comments on critical changes to preempt reviewer questions.
• Requesting targeted reviews: Use GitHub’s request review feature to involve domain experts.
• Leveraging the Graphite PR inbox: The inbox categorizes PRs, helping reviewers prioritize your refactor in the "Needs your review" section, while returned PRs automatically appear in "Returned to you".

maintain commit hygiene

Commit messages are an essential part of documenting your refactor. Ensure your commits:

• Are atomic: Each commit should represent a single, coherent change.
• Have descriptive messages: For example, instead of "fix stuff," use "Refactor user validation to handle edge cases."
• Squash unnecessary commits: Do this before merging to keep the repository history clean.

Example

When refactoring a file parser, your commit messages might include:

1. "Extract reusable parsing utilities."
2. "Refactor error handling for edge cases."
3. "Update unit tests for new parser structure."

Tools for better refactoring workflows

The Graphite PR inbox

The Graphite PR inbox acts as a centralized hub for your pull requests, helping you organize and prioritize refactoring tasks effectively. Key features include:

• Custom sections: Create a section for refactoring PRs to separate them from feature work.
• Fuzzy search: Quickly locate specific PRs by keywords or authors.
• Team sharing: Share your custom filters and configurations with teammates to align on workflows.

By following these best practices and incorporating tools like the Graphite PR inbox, you can ensure that refactored pull requests are efficient, maintainable, and easy to review.