The value of a clean git history is often underestimated. I will explain one of the advantages based on the git bisect command.
bisect stands for “binary search commit”
Haha, that is a funny misunderstanding. “bisect” stands for bisect. It is a word. It means to cut in half. Because the command cuts the range of suspicious commits into two, then tests which half the problem started in.
to divide into two usually equal parts
But I guess it can be misread as BInary SEarch CommiT.
I swear, I didn’t come up with that myself, I read that somewhere else, but of course I don’t have a source anymore 🙈 Maybe some git developer is a huge fan of wordplays?
All of this can only work with a clean git history containing only working commits.
This isn’t really true.
- You can use
git bisect skipto skip commits that can’t be evaluated. So if you are tracking down the failure of testfooand this commit fails to build, you can skip it. - If all merged commits are green then you can use
--first-parentto avoid testing inside a development branch. This way you can identify which merge caused the issue, even if other merges had broken commits.
So it is easier in general if you have all working commits, but it isn’t necessary. Really as long as you have green history on your main branch you will be able to get good results without much effort. I would highly suggest using some sort of merge-queue based workflow to ensure that the master branch is always green.
I would generally prefer using
--first-parentrather than forcing squashing. As smaller commits can be much easier to understand and the fact that commit IDs don’t change when being merged can make it much easier to manage stacked PRs and hotfix backporting.I agree that some stuff is easier when not squashing commits, but for the teams I’ve been working with I’ve felt that the pros of squashing outweigh the cons, but of course YMMV.
But I didn’t know about
git bisect skip, thanks for the tip! But sincere question: What happens if there are e.g. three adjacent broken commits? If I have skip all three of those and the error was introduced in one of them, then git cannot tell me which commit introduced the error, right?Yeah, if the problem was introduced in the skipped commits or the commit after the skipped commits git won’t be able to tell the difference. It it will only be able to know that it was one of those N+1 commits.
But as long as most of your commits are green it should be easy enough to do the final narrowing.
- You can use
