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Rethinking Code Reviews with Stacked PRs

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Rethinking Code Reviews with Stacked PRs

Introduction

In the realm of software development, code reviews are a cornerstone of quality assurance, fostering collaboration and knowledge sharing. However, traditional code review processes can often be cumbersome, leading to delays, frustration, and decreased productivity. Enter stacked pull requests (PRs), a novel approach that reimagines code reviews by breaking down complex changes into manageable, independent units.

Stacked PRs offer a streamlined and efficient way to manage code changes, enabling developers to:

Focus on smaller, digestible chunks of code:
This reduces cognitive load and makes reviews more manageable.
Reduce review times:
Faster reviews lead to quicker feedback cycles and faster deployments.
Improve code quality:
Addressing individual changes in isolation facilitates better code scrutiny.
Enhance collaboration:
Stacking PRs fosters better communication and teamwork.

This article delves into the nuances of stacked PRs, exploring the benefits, potential challenges, and best practices to effectively implement this approach in your development workflow.

Understanding Stacked PRs

Stacked PRs, also known as "squash and merge" or "cherry-pick" workflows, involve creating a series of independent pull requests that build upon each other. Each PR focuses on a specific change or feature, allowing reviewers to concentrate on a limited scope of work.

For example, consider a complex feature requiring multiple changes to different files. Instead of creating a single monolithic PR, a developer can break down the feature into smaller, self-contained PRs, each addressing a distinct aspect:

PR 1: Refactor database schema
- Focuses solely on updating the database structure.
PR 2: Add new API endpoint
- Introduces the new functionality without touching the database changes.
PR 3: Implement UI changes
- Modifies the front-end components to interact with the new API.

Each PR is reviewed and merged independently, ensuring that changes are thoroughly vetted before integrating them into the main branch. This approach allows for more granular code analysis, faster feedback loops, and smoother integration of changes.

Benefits of Stacked PRs

Stacked PRs offer several significant benefits that can enhance the code review process and overall development workflow:

Faster Review Cycles

Smaller, focused PRs are inherently easier and quicker to review. Reviewers can concentrate on a limited scope of changes, reducing the time spent on each PR. This accelerated feedback cycle enables faster issue resolution and quicker integration of changes.

Improved Code Quality

By breaking down changes into manageable units, reviewers can provide more detailed and accurate feedback. The isolation of changes also makes it easier to identify potential conflicts, ensuring that each PR integrates seamlessly into the existing codebase.

Reduced Cognitive Load

A single monolithic PR can overwhelm reviewers with a large volume of changes, making it difficult to grasp the overall impact and potentially missing crucial details. Stacked PRs alleviate this cognitive burden by presenting changes in digestible chunks, allowing reviewers to focus their attention effectively.

Enhanced Collaboration

Stacked PRs encourage a more collaborative approach to code review. Developers can work in parallel on different parts of a feature, while reviewers can provide feedback and approve changes independently. This fosters a more agile and efficient development process.

Easier Troubleshooting and Debugging

In case of issues or bugs, isolating changes into separate PRs makes it easier to identify the source of the problem. Reviewers can quickly pinpoint the PR that introduced the bug and focus their efforts on fixing it, saving time and effort.

Implementing Stacked PRs

Implementing stacked PRs requires a strategic approach and a well-defined workflow. Here's a step-by-step guide to incorporating this technique into your development process:

Define a Clear Branching Strategy

Establish a branching strategy that supports the concept of stacked PRs. A common approach is to create a feature branch for each individual PR. For instance, if you're working on a "new user registration" feature, you might create branches like:

feature/registration-db-changes
feature/registration-api
feature/registration-ui

This ensures that each PR is independent and can be merged into the main branch without impacting other changes.

Create and Review Independent PRs

For each feature or change, create a separate PR focusing on a specific aspect or component. Remember to keep PRs small and focused, ensuring that each PR represents a cohesive and well-defined change.

Review each PR individually, providing constructive feedback and approving changes only when satisfied with the code quality and functionality. This step-by-step approach ensures that each change is thoroughly scrutinized before merging into the main branch.

Leverage "Squash and Merge" or "Cherry-Pick"

Once a PR is reviewed and approved, you can merge it into the main branch using either "squash and merge" or "cherry-pick" options.

Squash and Merge: Combines all commits within a PR into a single commit, making the history cleaner and more manageable.
Cherry-Pick: Selects specific commits from a PR and applies them to another branch, allowing for selective integration of changes.

Choosing the appropriate merge strategy depends on your team's preferences and the specific workflow.

Keep Track of Dependencies

When working with stacked PRs, it's crucial to maintain a clear understanding of dependencies between PRs. Make sure to link related PRs in the description, using keywords like "depends on" or "follows" to highlight the connection. This ensures that the order of integration is maintained, preventing conflicts and ensuring a smooth merging process.

Communication and Collaboration

Effective communication is vital when using stacked PRs. Ensure that all team members are aware of the approach and understand how to create and review stacked PRs. Regular communication and open discussions can help resolve any potential issues and ensure a seamless workflow.

Potential Challenges and Best Practices

While stacked PRs offer numerous benefits, it's important to be aware of potential challenges and best practices to maximize the effectiveness of this approach.

Challenges:

Increased Overhead: Managing multiple PRs can add overhead in terms of creating, reviewing, and merging them. This requires disciplined planning and a well-defined workflow.
Complexity in Dependencies: Tracking dependencies between PRs can become intricate, especially for large or complex projects. Proper documentation and clear communication are essential to prevent confusion.
Limited Context: Reviewing individual PRs in isolation can sometimes lead to a lack of context, potentially missing broader implications or potential conflicts.
Increased Merge Conflicts: As PRs are merged individually, it's possible to encounter merge conflicts, requiring additional effort to resolve them.

Best Practices:

Keep PRs Small and Focused: Limit each PR to a single, well-defined change or feature. This promotes efficient reviews and reduces cognitive load.
Document Dependencies Clearly: Use clear language in PR descriptions to define dependencies between PRs. This ensures that the integration order is maintained.
Utilize Code Review Tools: Leverage code review platforms with features like PR linking and dependency tracking to streamline the process.
Encourage Open Communication: Foster an environment where developers openly discuss dependencies, potential conflicts, and any challenges encountered.
Review Early and Often: Encourage reviewers to provide feedback as soon as possible to catch issues early in the development cycle.
Iterate and Refine: Continuously evaluate the effectiveness of stacked PRs and adjust the workflow based on feedback and experience.

Conclusion

Rethinking code reviews with stacked PRs offers a powerful way to improve the quality, efficiency, and collaboration of software development. By breaking down complex changes into smaller, manageable units, stacked PRs streamline the review process, foster faster feedback cycles, and enhance code quality. However, implementing this approach requires careful planning, clear communication, and a well-defined workflow.

By embracing the benefits and addressing potential challenges, teams can leverage stacked PRs to transform their code review processes, leading to more efficient, collaborative, and productive development cycles.