Jujutsu for everyone

Do you want another person (or yourself in the future) to be able to read your commits, in order, to get a clear account of what changed & why? If so, you should fix up those commits to address mistakes. If not, it doesn’t matter.

Not the OP but for me, no I don't actually.

In a PR branch, my branches usually have a bunch of WIP commits, especially if I've worked on a PR across day boundaries. It's common for more complex PRs that I started down one path and then changed to another path, in which case a lot of work that went into earlier commits is no longer relevant to the picture as a whole.

Once a PR has been submitted for review, I NEVER want to change previous commits and force push, because that breaks common tooling that other team mates rely on to see what changes since their last review. When you do a force push, they now have to review the full PR because they can't be guaranteed exactly which lines changed, and your commit message for the old pr is now muddled.

Once the PR has been merged, I prefer it merged as a single squashed commit so it's reflective of the single atomic PR (because most of the intermediary commits have never actually mattered to debugging a bug caused by a PR).

And if I've already merged a commit to main, then I 100% don't want to rewrite the history of that other commit.

So personally I have never found the commit history of a PR branch useful enough that rewriting past commits was beneficial. The commit history of main is immensely useful, enough that you never want to rewrite that either.

It’s useful for me to see the mistake and the fix, as it is a good way to jog my memory about the “why” of things. Pristine commit history is not important to me.

When you force push a PR, Gitlab shows the changes from the last push. So it also depends which forge you use. I could see that working less well on Github or simpler Git forges

> Once the PR has been merged, I prefer it merged as a single squashed commit so it's reflective of the single atomic PR (because most of the intermediary commits have never actually mattered to debugging a bug caused by a PR).

While working on a maintenance team, most of the projects we handled were on svn where we couldn't squash commits and it as been a huge help enough times that I've turned against blind squashing in general. For example once a bug was introduced during the end-of-work linting cleanup, and a couple times after a code review suggestion. They were in rarely-triggered edge cases (like it came up several years after the code was changed, or were only revealed after a change somewhere else exposed them), but because there was no squash happening afterwards it was easy to look at what should have been happening and quickly fix.

By all means manually squash commits together to clean stuff up, but please keep the types of work separate. Especially once a merge request is opened, changes made from comments on it should not be squashed into the original work.

Yes, but in that case, I want the fix of the original mistake to be done in a new commit.

Why?

Example #1: - I am working on implementing API calls in the client, made 3 commits and opened a PR - In the meantime, the BE team decides they screwed up and need to update the spec

If I now go and fix it in the commit #1, I lose data. I both lose the version where the API call is in its original state, and I lose the data on what really happened, pretending everything is okay.

Example #2: - I am writing a JVM implementation for our smart-lens - In commit #2 I wrongly implement something, let's say garbage collection, and I release variables after they have 2 references due to a bug. - I am now 6 commits ahead and realise "oh shit wait I have a bug"

If I edit it inline in commit #2, I lose all the knowledge of what the bug was, what the fix is, what even happened or that there was a bug.

tldr: just do an interactive rebase

Yeah I don't have much experience outside of GitHub for team projects, so maybe gitlab works better. For GitHub it just gives up and claims it can't give you diff since the last review

I wonder by your last comment if this is just is talking past each other.

I try very hard to keep my PRs very focused on one complete unit of work at a time. So when the squash happens that single commit represents one type of change being made to the system.

So when going through history to pinpoint the cause of the big, I can still get what logical change and unit of work caused the change. I don't see the intermediary commits of that unit of work, but I have not personally gotten value out of that level of granularity (especially on team projects where each person's commit practices are different).

If I start working on one PR that starts to contain a refactor or change imthat makes sense to isolate, I'll make that it's own pr that will be squashed.

GitHub is basically worst in class here, it’s true. Some forges are slightly better, others are way better. It’s so sad because I like GitHub overall but this is a huge weakness of it.

Most of the bad modern Git practices summed up in one comment (one atomic, squashed comment).

From what I understand of how jj works, and I’m happy to be corrected because I’m still learning it, is that going back and editing those commits doesn’t change actual original “change” - that is, jj tracks a change ID to everything, and those original commits (once pushed) are immutable. So in theory, with jj, you should be able to see the original commit and the change to fix it, and you can still couple them into a single commit without losing that change history.