When working with large codebases, code reviews become more challenging due to the complexity and size of the project. A well-organized codebase not only improves the development workflow but also significantly streamlines the code review process. In this guide, we'll explore how to organize large codebases for review, ensure efficient code reviews in big projects, and simplify the process of reviewing large codebases.
Structuring your project for easier reviews
The way your codebase is structured plays a key role in making reviews smoother and more efficient. A disorganized or monolithic project can overwhelm reviewers and lead to slower feedback cycles. Here’s some strategies that show how to set up a codebase for optimal review efficiency.
Modularize the codebase
Modularization refers to the practice of organizing code into separate components or services based on functionality. Each module should have its own clear purpose, ideally isolated from the rest of the system, so that changes within one module don’t affect others unnecessarily.
For example, in a web application, you could divide the codebase into modules like:
- Frontend: User interface components, stylesheets, and related logic.
- Backend: APIs, services, and database interactions.
- Utilities: Shared helper functions or libraries used across the project.
When changes are confined to a specific module, reviewers can focus on the context of that module rather than being overwhelmed by the entire system.
Maintain consistent folder structures
Consistency is key in large codebases. Having an established, predictable folder structure helps reviewers find files quickly and navigate the codebase more effectively. For instance, organizing components, services, and utilities in their dedicated directories with uniform naming conventions aids both developers and reviewers.
Example:
/src/components/Button/Modal/services/api/auth/utils/formatters/validators
This helps reduces the time spent on figuring out where files are located, and it allows reviewers to focus more on the quality of the code rather than the structure of the project.
Writing smaller, focused pull requests
The size of a pull request (PR) directly impacts how efficiently it can be reviewed. Large, complex PRs often overwhelm reviewers and result in slower feedback. Here’s how you can ensure efficient code reviews in big projects by focusing on PR organization.
Create smaller PRs
Small, self-contained pull requests allow for more focused and efficient reviews. These PRs should aim to address a single feature, fix, or enhancement rather than bundling multiple changes together.
For instance, instead of submitting a PR that contains frontend changes, API adjustments, and database modifications all at once, break them into separate PRs:
- PR 1: Frontend component implementation.
- PR 2: API service updates.
- PR 3: Database schema migration.
By reviewing changes in isolation, reviewers can give more meaningful feedback without being overwhelmed.
Stack PRs for incremental changes
When working on large features or refactors, you may need to submit several interdependent PRs. Stacking PRs is a technique where you break a large feature into a series of smaller, logically connected PRs that build upon one another. Each PR in the stack is reviewable on its own, while the stack as a whole represents the full feature. Tools like Graphite make it easy to manage and stack your PRs because they ensure that changes are organized and reviewers can review incremental updates without losing context.
Stacking PRs with Graphite enables developers to maintain smaller, focused reviews, all while guaranteeing that each change is manageable and reducing the cognitive load for reviewers.
Use clear and concise commit messages
Good commit messages provide context and help reviewers understand the purpose of a change. Always ensure that each commit corresponds to a logical unit of work. Avoid bundling unrelated changes into a single commit, which makes the review process cumbersome.
A clear commit message should follow a pattern like:
[Type] (Scope): [Description]
Example:
feat(auth): Add new OAuth2 login mechanism
This message immediately informs the reviewer about the change, improving the efficiency of reviewing large codebases.
Documenting the codebase for reviews
Comprehensive and up-to-date documentation makes reviewing a large codebase more manageable. It provides essential context, especially when new reviewers or team members are unfamiliar with parts of the system.
Maintain a contribution guide
For efficient code reviews in big projects, create a contributing guide that outlines the standards and practices developers should follow. This guide should include information about:
- How to structure and submit PRs.
- Code formatting and styling conventions.
- Testing requirements before submitting changes.
This not only sets expectations but also reduces friction in the review process as reviewers know that the submitted code adheres to the agreed-upon standards.
Keep technical documentation current
In large codebases, it's easy for technical documentation to become outdated. Regularly review and update documentation to reflect the current state of the project. Whether it's architecture diagrams, API documentation, or readmes, keeping this information accurate helps reviewers understand the context of changes, especially when reviewing large codebases that may span multiple subsystems.
Automated tools for efficient reviews
Automation can greatly enhance the review process in large projects. By integrating automated checks, you can reduce the manual effort required to verify code quality and compliance.
Leverage linters and code formatters
Before submitting code for review, linters and code formatters ensure that the changes adhere to style guidelines and best practices. Tools like ESLin (for JavaScript) or Pylint (for Python) automatically highlight potential issues like unused variables, missing semicolons, or inconsistent formatting.
By catching these minor issues early on, reviewers can focus on the logic and architecture of the code rather than nitpicking style issues.
Use automated tests
Automated testing tools run unit, integration, and functional tests before the review process even starts. This ensures that new changes don’t break existing functionality. Including a test suite that automatically runs with each PR can save reviewers significant time in manual testing and allow them to concentrate on the overall quality and efficiency of the code.
A continuous integration (CI) pipeline with automated tests helps maintain a robust codebase, ensuring that reviews can proceed smoothly even in large codebases.
Use Graphite for better review workflows
Graphite helps streamline code review workflows, particularly in large projects where PR management can become a bottleneck. By integrating Graphite into your code review process, you can stack PRs, visualize dependencies between changes, and keep the review process organized. Graphite also provides advanced insights into PR metrics, helping you track the efficiency of your reviews and identify potential bottlenecks. With its focus on improving the code review lifecycle, Graphite helps teams maintain velocity while ensuring high code quality.
Tagging and assigning reviewers strategically
For better organization and faster feedback in reviewing large codebases, it's essential to involve the right reviewers. Here's how you can optimize the process.
Assign reviewers based on domain expertise
In large projects, different developers often specialize in particular areas. Assigning reviewers who are most familiar with the module being changed ensures faster, more relevant feedback. For example, a reviewer with deep knowledge of the authentication system should handle changes related to authentication.
Tag PRs with labels
Using labels like bug fix, feature, or documentation update helps reviewers prioritize their workload and focus on the most critical PRs. Labels also provide clarity and context at a glance, further aiding in the efficient review of large codebases.
Key takeaways
Organizing a large codebase for better reviews is not just about the code itself, but also about establishing clear processes, modular structures, and effective communication. By following these practices, you’ll streamline the process of reviewing large codebases and make it easier for teams to manage complex projects while maintaining high code quality.
