git bisect

git bisect is a nifty little Git command that really helps when you’re investigating a bug in your codebase. Within a few commands, you can systematically step through hundreds of commits and find the one that broke your build.

Transcript

1. git bisect Git logo by Jason Long is licensed under CC BY 3.0.
2. master v4.2
3. master v4.2 $ git bisect start
4. master $ git bisect start $ git bisect bad master v4.2
5. master $ git bisect start $ git bisect bad master $ git bisect good v4.2 v4.2
6. master $ git bisect start $ git bisect bad master $ git bisect good v4.2 Bisecting: 675 revisions left to test after this (roughly 10 steps) HEAD v4.2
7. master $ git bisect bad Bisecting: 337 revisions left to test after this (roughly 9 steps) HEAD v4.2
8. master $ git bisect bad d870dcf is the first bad commit HEAD v4.2
9. $ git bisect run npm test $ git bisect skip $ git bisect terms $ git bisect replay
10. Thank you, @sonicdoe sonicdoe.com/concat-2018