I recently wrote a #ruby gem to compare two SimpleCov runs: simplecov-compare. I wrote up a long-form post on my blog about why and how it works.

https://kevinjmurphy.com/posts/announcing-simplecov-compare/

Announcing simplecov-compare

SimpleCov::Compare is a gem to find the lines coverage difference between two SimpleCov runs.

Kevin Murphy
Thanks to @marcoroth for Glamour so it can look all fancy in the terminal.
@kevin_j_m Awesome! Thanks giving it a shot! ✨