Provided are methods and systems for monitoring code changes sent for review during the code review process, and performing test coverage calculations on the code changes to generate corresponding test coverage data. A code coverage service monitors code changes input to a code review system and automatically performs test coverage calculations on any code change determined to have significantly evolved as a result of the code review process. The code coverage service provides a notification of the resulting test coverage data (e.g., test coverage number) to various users and/or systems associated with the code change, including the code reviewer, the author of the code, the code review system, other notification systems, and/or any combination thereof. The test coverage data can be utilized in a comprehensive assessment of the code health of the relevant code involved.