# Code Review Process

This document outlines the code review process for the LCFS project. Effective code reviews are crucial for maintaining code quality, sharing knowledge, and fostering a collaborative development environment. This addresses requirements for ticket #2410.

## 1. Purpose of Code Reviews

*   **Improve Code Quality**: Catch bugs, logical errors, and deviations from coding standards.
*   **Ensure Readability & Maintainability**: Verify that code is clear, understandable, and easy to maintain.
*   **Knowledge Sharing**: Help team members learn about different parts of the codebase and new techniques.
*   **Mentorship**: Provide opportunities for junior developers to learn from senior developers, and vice-versa.
*   **Collective Ownership**: Foster a sense of shared responsibility for the codebase.
*   **Validate Against Requirements**: Ensure the implemented solution meets the intended requirements of the feature or bug fix.

## 2. Before Requesting a Review (Author's Responsibility)

Before submitting a Pull Request (PR) for review, the author should:

1.  **Self-Review**: Review your own code first. Check for typos, obvious errors, and adherence to style guides.
2.  **Test Thoroughly**: Ensure all [Testing Procedures](Testing-Procedures.md) have been followed:
    *   Relevant unit and integration tests are written and pass.
    *   E2E tests (if applicable to the changes) pass.
    *   Manual testing of the feature/fix has been performed.
3.  **Ensure CI Checks Pass**: All automated checks in the CI pipeline (linters, formatters, automated tests, builds) must be passing.
4.  **Clear PR Description**: Write a clear and concise PR description:
    *   Explain *what* changes were made and *why*.
    *   Link to the relevant issue(s) in the issue tracker.
    *   Provide clear steps for reviewers to test or verify the changes.
    *   Include screenshots or GIFs for UI changes.
5.  **Keep PRs Focused and Manageable**: 
    *   Submit small, focused PRs where possible. Large PRs are difficult and time-consuming to review effectively.
    *   If a feature is large, break it down into smaller, logical PRs.
6.  **Check for Debugging Code**: Remove any temporary debugging code (e.g., `console.log`, `print` statements not intended for production).

## 3. The Review Process (Reviewer's Responsibility)

Reviewers should aim to provide constructive, respectful, and timely feedback.

### 3.1. Understanding the Changes

*   Read the PR description and linked issues to understand the context and purpose of the changes.
*   Try to understand the overall approach before diving into line-by-line details.

### 3.2. Key Areas to Review

*   **Functionality**: Does the code work as intended and meet the requirements?
    *   If possible, pull down the branch and test the changes locally.
*   **Correctness**: Are there any logical errors, race conditions, or edge cases missed?
*   **Readability & Simplicity**: Is the code clear, concise, and easy to understand? Could it be simpler?
*   **Maintainability**: Is the code well-structured? Will it be easy to modify or debug in the future?
*   **Adherence to Standards**: Does the code follow [Coding Standards and Conventions](Coding-Standards-and-Conventions.md)?
*   **Testing**: Are there sufficient tests for the changes? Do the tests cover important scenarios and edge cases? ([Testing Procedures](Testing-Procedures.md))
*   **Security**: Are there any potential security vulnerabilities introduced? (See [Security Guidelines for Developers](Security-Guidelines-for-Developers.md))
*   **Performance**: Are there any obvious performance bottlenecks or inefficiencies?
*   **Documentation**: Is new code adequately commented? Is any related documentation (e.g., READMEs, other wiki pages) updated if necessary?
*   **Naming**: Are variables, functions, and classes named clearly and appropriately?
*   **Error Handling**: Is error handling robust and user-friendly (if applicable)?

### 3.3. Providing Feedback

*   **Be Specific**: Refer to specific lines of code or files.
*   **Be Constructive**: Offer suggestions for improvement rather than just criticism.
*   **Explain Your Reasoning**: If you suggest a change, explain why it's better.
*   **Distinguish Importance**: Differentiate between critical issues, important suggestions, and minor nits (e.g., use prefixes like "Nitpick:" or "Suggestion:").
*   **Use GitHub's Review Tools**: Add comments directly to the code in the PR. Use "Request changes," "Approve," or "Comment" appropriately.
*   **Be Timely**: Aim to review PRs within a reasonable timeframe (e.g., 1-2 business days, as per team agreement).

## 4. After Receiving Feedback (Author's Responsibility)

*   **Acknowledge Feedback**: Respond to comments, indicating whether you agree or want to discuss further.
*   **Make Necessary Changes**: Address the feedback by making code changes, pushing new commits to the same PR branch.
*   **Clarify if Needed**: If you disagree with a suggestion or don't understand it, discuss it respectfully with the reviewer.
*   **Re-request Review**: Once changes are made, notify the reviewer(s) that the PR is ready for another look (GitHub often does this automatically when you push to the PR branch).

## 5. Approval and Merging

*   **Approval**: Typically, at least one approval (or as per team policy) is required before a PR can be merged.
*   **CI Checks**: All CI checks must be passing.
*   **Merging**: Once approved and checks pass, the PR can be merged into the target branch (e.g., `main` or `develop`).
    *   Refer to [Git Workflow and Branching](Git-Workflow-and-Branching.md#3-pull-request-pr-process) for preferred merge strategies (e.g., squash and merge).
*   **Delete Branch**: The feature branch should be deleted after the PR is merged.

## 6. Number of Reviewers

*   **Action**: Define the team's policy on the number of reviewers required (e.g., one for most PRs, two for critical changes).

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*A positive and collaborative code review culture is key to a healthy and productive development team. Treat reviews as a learning opportunity for everyone involved.*