Git squash commits in the middle of a branch
stackoverflow.com
I want to squash several commits together in the middle of a branch without modifying the commits before and after. I have : A -- B -- C -- D -- E -- F -- G | | master...

So I've just learned that git rebase -i allows users to merge individual commits in the middle of a branch's history. For that,

$ git rebase -i

This should bring a list of all commits in reverse order, similar to the one listed below:

pick 2361d4d implements something
pick a700451 fixes a bug
pick 79f9d04 fixes a bug again
pick 3172f07 implements some other thing

# Rebase 484d6d2..3172f07 onto 484d6d2 (4 commands)
#
# Commands:
# p, pick  = use commit
# r, reword  = use commit, but edit the commit message
# e, edit  = use commit, but stop for amending
# s, squash  = use commit, but meld into previous commit
# f, fixup [-C | -c]  = like "squash" but keep only the previous
#                    commit's log message, unless -C is used, in which case
#                    keep only this commit's message; -c is same as -C but
#                    opens the editor
# x, exec  = run command (the rest of the line) using shell
# b, break = stop here (continue rebase later with 'git rebase --continue')
# d, drop  = remove commit
# l, label  = label current HEAD with a name
# t, reset  = reset HEAD to a label
# m, merge [-C  | -c ]  [# ]

It's possible to merge commit 79f9d04 with a700451 by updating the list of commands to set squash instead of pick in the commit you want to flatten onto the previous one, such as:

pick 2361d4d implements something
pick a700451 fixes a bug
squash 79f9d04 fixes a bug again
pick 3172f07 implements some other thing

(...)

Once we save the commit, Git opens an editor to rework the new commit message for the squashed commits, and you're set.

  • pudcollar [he/him]
    ·
    1 year ago

    I'm one of those guys who doesn't even merge. I use rebase for everything. Rebase -i is really powerful. One command to remember to rewrite a message, squash commits, delete commits, etc.

    • naonintendois@programming.dev
      ·
      1 year ago

      You should also check out git commit --fixup ... paired with git rebase -i --autosquash .... you specify a commit target to the fixup to say you want to fix that commit with the code you're currently committing. It will create a fixup commit at HEAD. The auto squash will reorder your fixup commit and mark it as a squash so you have way less work to do.

      • lysdexic@programming.dev
        ·
        1 year ago

        You should also check out git commit --fixup ... paired with git rebase -i --autosquash ....

        Superb tip. I'm reading up on the feature, and it sounds like the process I've just learned but on steroids. Thanks for the pro tip!