minio/PULL_REQUESTS_ETIQUETTE.md

MinIO Pull Request Guidelines

These guidelines ensure high-quality commits in MinIO’s GitHub repositories, maintaining a clear, valuable commit history for our open-source projects. They apply to all contributors, fostering efficient reviews and robust code.

Why Pull Requests?

Pull Requests (PRs) drive quality in MinIO’s codebase by:

• Enabling peer review without pair programming.
• Documenting changes for future reference.
• Ensuring commits tell a clear story of development.

A poor commit lasts forever, even if code is refactored.

Crafting a Quality PR

A strong MinIO PR:

• Delivers a complete, valuable change (feature, bug fix, or improvement).
• Has a concise title (e.g., [S3] Fix bucket policy parsing #1234) and a summary with context, referencing issues (e.g., #1234).
• Contains well-written, logical commits explaining why changes were made (e.g., “Add S3 bucket tagging support so that users can organize resources efficiently”).
• Is small, focused, and easy to review—ideally one commit, unless multiple commits better narrate complex work.
• Adheres to MinIO’s coding standards (e.g., Go style, error handling, testing).

PRs must flow smoothly through review to reach production. Large PRs should be split into smaller, manageable ones.

Submitting PRs

1. Title and Summary:

   • Use a scannable title: [Subsystem] Action Description #Issue (e.g., [IAM] Add role-based access control #567).
   • Include context in the summary: what changed, why, and any issue references.
   • Use [WIP] for in-progress PRs to avoid premature merging or choose GitHub draft PRs.

2. Commits:

   • Write clear messages: what changed and why (e.g., “Refactor S3 API handler to reduce latency so that requests process 20% faster”).
   • Rebase to tidy commits before submitting (e.g., git rebase -i main to squash typos or reword messages), unless multiple contributors worked on the branch.
   • Keep PRs focused—one feature or fix. Split large changes into multiple PRs.

3. Testing:

   • Include unit tests for new functionality or bug fixes.
   • Ensure existing tests pass (make test).
   • Document testing steps in the PR summary if manual testing was performed.

4. Before Submitting:

   • Run make verify to check formatting, linting, and tests.
   • Reference related issues (e.g., “Closes #1234”).
   • Notify team members via GitHub @mentions if urgent or complex.

Reviewing PRs

Reviewers ensure MinIO’s commit history remains a clear, reliable record. Responsibilities include:

1. Commit Quality:

   • Verify each commit explains why the change was made (e.g., “So that…”).
   • Request rebasing if commits are unclear, redundant, or lack context (e.g., “Please squash typo fixes into the parent commit”).

2. Code Quality:

   • Check adherence to MinIO’s Go standards (e.g., error handling, documentation).
   • Ensure tests cover new code and pass CI.
   • Flag bugs or critical issues for immediate fixes; suggest non-blocking improvements as follow-up issues.

3. Flow:

   • Review promptly to avoid blocking progress.
   • Balance quality and speed—minor issues can be addressed later via issues, not PR blocks.
   • If unable to complete the review, tag another reviewer (e.g., @username please take over).

4. Shared Responsibility:

   • All MinIO contributors are reviewers. The first commenter on a PR owns the review unless they delegate.
   • Multiple reviewers are encouraged for complex PRs.

5. No Self-Edits:

   • Don’t modify the PR directly (e.g., fixing bugs). Request changes from the submitter or create a follow-up PR.
   • If you edit, you’re a collaborator, not a reviewer, and cannot merge.

6. Testing:

   • Assume the submitter tested the code. If testing is unclear, ask for details (e.g., “How was this tested?”).
   • Reject untested PRs unless testing is infeasible, then assist with test setup.

Tips for Success

• Small PRs: Easier to review, faster to merge. Split large changes logically.
• Clear Commits: Use git rebase -i to refine history before submitting.
• Engage Early: Discuss complex changes in issues or Slack (https://slack.min.io) before coding.
• Be Responsive: Address reviewer feedback promptly to keep PRs moving.
• Learn from Reviews: Use feedback to improve future contributions.

Resources

• MinIO Coding Standards
• Effective Commit Messages
• GitHub PR Tips

By following these guidelines, we ensure MinIO’s codebase remains high-quality, maintainable, and a joy to contribute to. Happy coding!