What is Code Review?¶

Overview¶

Code review is the process of making pieces of source code available for other developers to review, with the intention of catching bugs and design errors before the code becomes part of the product.

Code review dramatically helps in the quality of products. By catching mistakes early, a lot of bad problems in a product can be avoided. Not all companies or developers take advantage of code review, but more and more are making it a part of their development culture and requirements.

Types of Code Review¶

There are two types of code review: pre-commit and post-commit.

Pre-commit review is a form of code review where code is reviewed before going into the codebase. In this method, a diff file is uploaded to Review Board, which reviewers can comment on, and once there’s approval the code is committed to the repository.

Post-commit review is where the code is reviewed after going into the codebase. The code is committed to the repository and, at some point later, the code is reviewed. Any fixes that need to be made are then committed again later.

The advantage of pre-commit review over post-commit review is that mistakes are caught before they become part of the product. The downside is that development may take longer.

Review Board supports both styles of code review. For pre-commit reviews, an uncommitted change can be uploaded either through the web UI, or using the rbt post tool.

For post-commit reviews, depending on the repository type, Review Board allows you to browse the commit history and choose a change to review. All repository types are supported for post-commit review by using the rbt post tool to prepare a diff file for the change and upload it.