Optimizing Pull Requests: Lines of Code and Code Reviews

In the realm of software development, the management of pull requests (PRs) is crucial for maintaining code quality and fostering efficient collaboration. A common question in this context is: how many lines of code should a pull request contain?

General Guidelines and Best Practices

At many companies, especially those adhering to best practices and strict coding standards, pull requests are a key part of the development lifecycle. One such guideline is that pull requests should ideally be atomic and specific to one issue or feature. This not only aids in easier revertibility but also helps in preserving the working functionality of the project. However, the size of these pull requests can sometimes pose challenges.

Challenges with Smaller PRs and User Stories

One common issue with excessively small pull requests and user stories is the tendency to lead to overly granular development. This can result in a fragmented and potentially less efficient codebase. For instance, a developer might add a single parameter to an enormous function or introduce another property to an already complex component, rather than refactoring the larger structure. This approach can encourage a piecemeal solution to complex problems without addressing underlying architectural or design issues.

Variations in Pull Request Length

There is no one-size-fits-all answer to the number of lines a pull request should contain. Factors such as the nature of the change, the specific codebase, and the complexity of the feature or bug fix involved can all play roles. Some companies have specific standards, such as requiring an architect's approval for PRs that exceed 500 lines or 50 files.

Benefits of Focused PRs

Despite the challenges mentioned, there are significant benefits to smaller, more focused pull requests. These include:

Improved code quality: Smaller and more focused changes are often easier to review and test, leading to higher code quality. Reduced complexity: Breaking down changes into smaller pieces can prevent the introduction of unnecessary complexity. Enhanced collaboration: Smaller pull requests make it easier to involve multiple developers in the review process, fostering a collaborative environment. Quick turnaround: Smaller changes can often be merged faster, reducing the time-to-market for new features or bug fixes.

Negotiating Larger PRs

There are scenarios where larger pull requests are necessary. For instance, changes that require extensive refactoring, updates to dependencies, or significant architectural changes may necessitate a larger PR. In such cases, it is essential to justify the size of the PR and ensure that it is adequately documented. This can be achieved through:

Detailed documentation: Providing clear documentation and rationale for the changes can help reviewers understand the necessity of the large PR. Stage-by-stage approach: Breaking down the change into smaller, logical segments can make the overall PR more manageable. Code reviews: Ensuring thorough and meticulous code reviews can mitigate risks associated with larger changes.

Conclusion

While there is no fixed line count for pull requests, the general recommendation is to strive for smaller, more focused changes. This approach not only enhances code quality and maintainability but also facilitates more efficient collaboration among developers. However, there should be room for flexibility when dealing with large, necessary changes that cannot be broken down further. By understanding the trade-offs and implementing best practices, teams can achieve a balance that optimizes both code quality and development efficiency.