Squashing buys you next to nothing, and costs you the ability to dive into the history in greater detail.
I suppose if your project is truly huge, it becomes worth it to reduce load on your VCS, but beyond that...
The "greater detail" part can cost me a lot of time.
I think representing history correctly is best, and agree that “squashing buys you next to nothing” other than visually pleasant output. Clearer?
My favorite approach is rebase + non-ff merge. Best of both worlds.
You think the disadvantage (destroying history) is more important, but you can't say that it "buys you nothing".
Ideally, each commit should be something that you could submit as a stand-alone patch to a mailing list; whether it's a single commit that was perfect from the get-go or fifty that you had to re-order and rewrite twenty times does not matter at all; the final commit message should contain any necessary background information.
It would be needlessly restrictive to prevent users from making intermediate commits if that helps their workflow: I want to be able to use my source-code management tool locally in whichever way I please and what you see publicly does not need to have to have anything to do with my local workflow. Thus, being able to "rewrite history" is a necessary feature.
Let alone the code review issue. In any multi-person project, it is just as important that your commit history be readable by a third party for information as that it be useful for your own personal debugging.
Compromises with human nature must be made. Hence -- we need to be able to rewrite history.
Your academic purism is out of place, dude. Real humans don't work like you say they do. Some do -- most don't.
By definition the actual history of your work includes WIP, so this means your commit history should not reflect the actual history of your work.
Just don't publish WIP crap; fortunately, you can have your cake and eat it too, with git.
The biggest reason git (and any similarly advanced SCM) is superior to non-distributed alternatives like Subversion is that I can use it to manage my own workflow, instead of just as the final off-site backup of whatever I decide to publish. I get to actually use everything git offers for shuffling commits and code around while coding.
Want to switch contexts quickly? git commit the whole thing and just switch a branch.
How about untangling a hairy merge? Do it piecemeal and commit when you're done with each bit; it's trivial to then undo mistakes, redo, combine or reorder stuff and you cannot lose any work by accident because git commits are immutable.
All of these features essentially require history rewriting; sure, you're free to rebrand and not call "store WIP state in repository" a commit even though it is one, but I would consider any SCM without these features nigh useless for most work.
Indeed they are, hence the need to rewrite the history. Managers, tech leads, or users of your OSS project don't care about the "fix typo" comments. They are interested in a meaningful history that tells a bigger story.
And to be frank, I am interested in the same, mid-term and long-term. While I am grappling with a very interesting problem for a month then yes, I'd love my messy history! But after I nail the problem and introduce the feature I'll absolutely rewrite history so the squashed PR commit simply says "add feature X" or "fix bug Y".
Why would they be looking at the version control system for this? That is not what it's there for.
And many tech leads simply don't have the time to review every single WIP commit. They want meaningful message/description of the big squashed PR commit. If you just post a merged list of all commit messages with 10x "fix stuff" inside you'll be in big trouble the next time around and your work will be inspected very closely.
The practices I am describing to you are reality in many tech companies. Writing code there is not about you at all. And almost nobody will read your code and PR descriptions unless they really have to. Hence it's a professional courtesy to make those as small and meaningful as possible.
Do you usually review every commit? I usually just review the diff between the PR'd branch and master, as does everyone I work with.
Whether you think that "makes no sense" is inconsequential. Many people find it very meaningful.
Why?
But it absolutely should when you work in a team. I'll personally scold you if you waste my time with merging a 20 commit PR of which 10 commmits are "fix stuff" or "fix typo" or "oops forgot variable" etc. It won't pass code review.
You are free to disagree. I am only telling you how it is in many companies.
2. Waste of later coders' time when running git blame on a line when trying to figure out the purpose of code
3. Waste of later debuggers' time when they need to decide whether this error is the thing they're looking for, an unrelated error to bisect skip, or an unrelated error in possibly-related code that they need to manually fix and then re-test.
Sure it does, but sometimes that level of detail in history is not helpful. Individual keystrokes are an even finer/"more accurate" representation of history; but who wants that? At some point, having more granular detail becomes noise - the root of the disconnect is that people have a difference in opinion on which level that is: for some (like you), it's at individual commit-level. For others (like me), it's at merge-level: inspecting individual commits is like trying to parse someone's stream-of-consciousness garbage from 2 years ago. I really don't care to know you were "fixing a typo" in a0d353 on 2019-07-15 17:43:32, but your commit is just tripping-up my git-bisect for no good reason.
If the author did something edgy or hard-to-understand with the change-set, I expect to see an explanation why it was done that way as a comment near the code in question, rather than as a sequence of commit-messages, that is the last place I will look - but that's just me
I mean, granted, it's not ideal. I think this is a bit of a problem with the low-level nature of git - Ideally it'd be easier to semantically bundle such sequences of commits such that it's be more reliably dealt with in the broader ecosystem (not every tool supports --first-parent), and in any case, there's nothing forcing you to maintain the first-parent-is-linear-mainline-history; that's just a tradition which, again, many common tools follow. Then of course there's the poor integration with git hosting (such as github) and git - I can blame a file, but I can't easily correlate that with the discussions in the PRs, and whatever correlation there is is purely online, with all the limitations of a single-vendor non-distributed system like that entails.
Ideally this wouldn't even be a tradeoff at all; it would be obvious how to track history both at the small scale and the larger scale (and perhaps even more?), but alas, it's what we have.
Out of curiosity - when you merge via squash, what kind of commit messages do you retain? Do you mostly concatenate the commit messages, or rewrite the whole thing?
Context-specific. For a bigger PR that deals with an extensive refactor I'll prefer to have a descriptive title and hand-curated task list below (so definitely not 1:1 to commit messages). For smaller PRs -- or more focused ones, like those dealing with a single feature or bug -- I'll only leave a descriptive title.
But I usually never leave a list of commit messages. Not because I have no discipline; sometimes some refactoring requires 4-5 steps and all commits have 99% identical messages which is not useful when you aggregate those in a single list of bullet points in the end.
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> But the problem with this approach is that you're making it impossible to extract the actual changes when you do want them, whereas simply skipping non-merge commits is a minor inconvenience (`--first-parent` tends to cover it).
Again, that's not the issue here. The issue is that when you work on a big project (like many of us do) you get something like 4-7 merged PRs a day; don't pull/fetch for 3 days and you'll get 60+ lines in your terminal when you get to it.
There are people who manage releases and people who chase subtle regressions. Having git bisect narrow it down to a big PR squashed commit is actually a win; it gives them a localized area inside which they can work with other tools (not bisect).
In the end I suppose we can say it's a subjective taste. But I always appreciated the main branch's history to only consist of squashed commits. Again, it gives you a good bird-eye's view.
You'd be surprised. It's only because we understand (and are used to) tool limitations (regarding storage, load, etc) that we don't advocate for that, not because some other way is philosophically better.
I'd absolutely like to have "every single version of the file which ever hit disk locally on my machine in the history".
And while those histories are typically unreadable, it is possible to label (even retroactively) relevant moments in "history"; and in any case just because a consumer-level wordprocessor doesn't export the history in a practical way doesn't mean a technical VCS couldn't do better - it just means we can't take git-as-is or google-docs-as-is and add millions of tiny meaningless "commits" and hope it does anything useful.
I understand the rationale but the balance tilts too far into the "too much details" territory for me and that can slow me down while digging.
What I found most productive for myself is that searching for a problematic piece should happen on a two-tiered tree, not a flat list. What I mean is: first find the big squashed PR commit that introduces the problem, then dig in more details inside of it.
Not claiming my way is better but for almost 20 years of career I observed it was good for many others as well, so I am not exactly an aberration either.
To me a very detailed history is mostly a distraction. Sure `git-bisect` works best on such a detailed micro-history but that's a sacrifice I am willing to make. I first use bisect to find the problematic squashed commit and then work on its details until I narrow down the issue.
I would say what you're describing is a break down in CI/CD and code review. How is code that is that broken getting into your default branch in the first place?
As to rebases to clean up history (and not just the PR itself)... personally, I don't think that's worth it. My experience with history like this is that it's relevant during review, and then around 95% of it is irrelevant - you may not know which 5 % are relevant beforehand, but it's always some small minority. It's worth cleaning up a PR for review, but not for posterity. And when it comes to review, I like commits like "pay respect to the linter gods" and the like, because they're easy to ignore, whereas if you touch code and reformat even slightly in one commit, it's often harder to skip the boring bits; to the point that I'll even intentionally commit poorly formatted code such that the diff is easy to read and then do the reformat later. Removing clear noise (as in code that changes back and forth and for no good reason) is of course nice, but it's easy to overdo; a few typo commits barely impact review-ability (imho), and rebases can and do introduce bugs - you must have encountered semantic merge conflicts before, and those are 10 times as bad with rebases, because they're generally silent (assuming you don't test each commit post-rebase), but leave the code in a really confusing situation, especially when people fix the final commit in the PR, but not the one were the semantic merge conflict was introduced, and laziness certainly encourages that.
It also depends on how proficient you are with merge conflicts and git chicanery. If you are; then the history is yours to reshape; but not everybody is, and then I'd rather review an honest history with some cruft, rather than a frankenstein history with odd seams and mismatched stuff in a commit that basically exists because "I kept on prodding git till it worked".
All due diligence is done there, not in the main branch.
The main branch only needs to have one big commit saying "merging PR #2169". If you need more details you'll go that PR/branch and get your info.
The "fix typo" commit being in the main branch buys you nothing. It's only useful in its separate branch.
Why not merge?
It gives you better high-level observability and a good bird's-eye view. And again -- if you need more details you can go and check all separate commits in the PR/branch anyway.
And finally, squashed commits are kind of atomic commits. Imagine history of three separate PRs happening at roughly the same time. And now all those commits are interspersed in the history of the main branch.
How is that useful or informative? It's chaos.
EDIT: my bad, I conflated merging with rebasing. Still, I prefer a single squashed commit for most of the reasons above, plus those of the other two commenters (useful git blame output and buildable history).
"Encrypt project's sensitive fields (#1234)"
With the number being a PR or an issue # (which does contain a link to the PR).
I do care about history in branches though. And many others do. I agree that it varies from team to team.
Also, in case it helps you in the future, `blame -wC` is what I use when doing blame; it ignores whitespace changes and tracks changes across files (changes happened before a rename, for example.)
I've come across "fix indentation" or "fix typo" commits where a bug was introduced, like someone accidentally comitted a change (maybe they were debugging something, or just accidentally modified it).
For example: I'm tracing a bug where a value isn't staying cached. I find a line of code DefaultCacheAge=10 (which looks way too short) and git blame shows the last change was modifying that value from 86400. What I do next will be very different if the commit message says "fix indentation" vs "added new foobar feature" or "reduced default cache time for (reason)".