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Comment by sighansen | Hacker News Reader

The commit messages are terrible. In my opinion, conventional commit messages [0] should be used for a clean commit history.

[0] https://www.conventionalcommits.org/en/v1.0.0/

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I question the value of commit messages at all. Sure, at some level you need a summary of what a change is trying to do, but we have that at 5 levels now and they are completely redundant. Generally there is a ticket in some system for tracking changes, whether it's Jira or Github itself or some other system. Then you have a PR/MR that is attached to a branch which you are trying to have merged. Then there are the commit messages themselves. These are all completely redundant to each other, and nobody in their right mind should want all of these at the same time. It's too many places to look for the same exact information, there's no reason to maintain it in more than one place.

Some truly awful standard for formatting commit messages, how to do something that has at best dubious value to begin with, is a fantastic way to give the appearance of work without the need for skill or ability or spending time trying to get useful work done, a true boon to incompetents and hangers on. It's also a great way to snipe someone's amazing work and put yourself in a position to critique them with 1/1000th of the effort of accomplishing something useful.

I think Jira messages are generally written from a product perspective ("here's what we want") whereas PR's are written from an implementation perspective ("here's how we did it"). And then the PR description ought to just become the squashed commit message (at least that's how my current company does it).

I value the commit messages in the context where you develop a tool that has to be run widely.

In particular, I had experience with Wine. Having useful commit messages allows you to do bisects and trace down regressions with more ease than cross-checking messages with some external ticket system, and when you have a lot of people contributing to a project it's easier to see what they're doing when they try to do a patch.

I also believe though, that it is good practice to help your colleagues when they do need to find an issue in a project where a lot of different people can work on.

This would boil down to merge level messages. Not all projects squash commits, so what you actually care about here are the mr/pr level messages, which might be approximated by the commit message on the merge commit, but actually probably will just say merge {branchname}. When you bisect with parent=0 you only see merge commits or ff directly against main branch.

Putting what im saying another way, in a project with pull requests, commit messages are redundant with the text typed into the pr and the comments on same. We should just carbon copy those onto the merge commit and forget per commit messages.

Code tends to live longer than projects management tools like JIRA. The version history should always be understandable from itself without access to external software. Not to mention that JIRA tickets should be based on concrete user stories while commit messages describe implementation details, they are different layers of concern. As for individual commit messages, you need to so the poor soul reviewing your MR knows what the hell you are doing.

Seriously, please think of the poor soul having to maintain you legacy code when the JIRA is long gone or the external contractor who doesn't even get access to it in the first place.

Then tooling should be set up to maintain the same information in multiple systems. I'm not saying that its not important to remember what people were trying to do, I'm saying the original theory for commit messages is completely nonexistent in modern development. People don't make single self contained commits directly to main branch. Since everyone uses some kind of pull request as the unit of merge, just keep the information on the mr and copuly it to the merge request message.

Something more descriptive than "Grrr" would be nice I guess.

They are really bad and I would feel bad if I presented something like that to someone for a review (not just messages - most of those commits shouldn't exist at all). That said, the MR in question is marked as a draft, so anything goes at that point.

Also, Conventional Commits are mostly pointless. Linux-style commit message conventions are enough.

CPython seems to use squash merges, which means only one commit will end up on the main branch after merging this PR. The history on branches is irrelevant and can be completely messy, full of merges and other experiments; the main branch has one commit per actual feature/change.

And eh, conventional commits seem like pointless bureaucracy to me.

With only +1,722 lines added, even if the commits were eventually squashed upon landing, I'd consider it good etiquette to tidy up changes to maybe a handful of logical commits instead of pushing 404 raw commits.

Or maybe it's another weird pun on 404 Not Found? I can't tell by now...

The end result of doing this is good, but I find it really difficult to cleanly do this before I have something that's 100% complete.

I don't code linearly like "first I need feature A, then I code feature B which is needed for feature C, and so on"

It's usually a bit all over the place and it's not clear what depends on what until I start reaching the end.

So to do this properly I'd need to spend a day or two rewriting or making a new branch that cleanly adds everything in order. Hopefully in a way that doesn't leave master in a broken state when reverting tail commits.

In addition, when doing multiple pull requests for a single high level feature, you might get some comments about pull request "C" that would require changes in pull request "A"

How the hell is someone supposed to review your pull request if you don't take the time to clean it up?

I normally go through every single individual commit when reviewing something and find the commit messages extremely helpful to understand what some change is supposed to do.

Yes, cleaning up your commits takes some time butt I don't see an alternative if you don't work alone and want your code to stay maintainable.

I review the pull request as a whole, looking at the diff between main and the latest commit on the branch (i.e. what GitHub/etc show by default). Reading commit-by-commit means you’d read code that the author knows is wrong and had already fixed it, but you’re cluttering your mind with it. During re-reviews, I usually look at the diff between the last commit I reviewed and the newest commit.

> Reading commit-by-commit means you’d read code that the author knows is wrong and had already fixed it

If the commit is wrong, it shouldn't be there. I expect every commit in a Pull Request to be functional on its own or I am not going to approve it in the first place. Git has tools to rewrite your commit history and you should use them.

The whole point is that I should be able to revert individual commits without code breaking. At least that is the ideal. A clean version history matters a lot of the people maintaining your code down the line.

Yes and no.

I think what you say is definitely the goal for day-to-day contributions.

However, there are changes to a code base that are more "Manhattan project" in nature where not all changes can be neatly packaged into their own commits, OR the PR author kind of needs to re-do their coding on a clean room branch. Which is significant overhead.

Being able to undo a commit is a means to an end, not the ultimative goal.

In my experience, this is very team-specific. Some teams want squash merges and ignore individual commits and only look at the latest version, while others care about the "history" and will tidy it up in the PR and then merge all the commits from the PR. Though I've found the latter to be much more rare, that's why some tools (like Reviewable https://docs.reviewable.io/reviews.html?highlight=commit-by-...) have a commit-by-commit option but the default is to combine them for review.

> I find it really difficult to cleanly do this before I have something that's 100% complete

That's what a DVCS like git makes easy to do, it's really worth learning.

Being honest though, the guy's commit messages influence my prior on how reliable and well-designed his code will be.

“My prior”. Give it a rest.

Just saying that if I were working with this person it wouldn't make me think highly of him, and in my fairly extensive experience I can report that there's a strong correlation between silly commit messages and not great code. I didn't mean to imply that I was qualified or skilled enough to evaluate the JIT compiler for Python.

I think I missed what your point was?

I understood the point to be about using accessible language rather than jargon.

You think "my prior" is jargon? I'm not sure what to say to you then. You realize Bayesian thinking in statistics has been around since the 1950s if not 1930s? https://en.wikipedia.org/wiki/History_of_statistics#Bayesian...

Bear in mind I'm interpreting the previous comment.

I'm familiar with many things Bayesian thanks :) However, I wouldn't assume everyone else is, even here.

Are you familiar with the meaning(s) of the word jargon? https://dictionary.cambridge.org/dictionary/english/jargon https://en.wikipedia.org/wiki/Jargon

Just to provide an example, your previous comment could have been written something like this: "Being honest though, the guy's commit messages changed my preconceptions about how reliable and well-designed his code will be."

No knowledge of statistics required, Bayesian or otherwise.

OK, fair enough, your suggestion is totally reasonable. However I've been referring to people's "priors" though in informal conversation for about 25 years, to friends, romantic partners, and family as well as academics and programmers, and I know several other people who do the same. Apart from anything else it's a nice non-technical sounding word. I'm not a Bayesian statistics zealot (I don't even work in statistics any longer). But I definitely think all educated people should be familiar with the _idea_ of Bayesian inference. I think that goes without saying. I'm no expert on such matters but clearly our own perception/cognition has some sort of Bayesian flavour to it (you think a mammal dimly perceived on the horizon is probably a dog etc). What I'm saying is -- it sound like perhaps you also have had some involvement with the academic subject -- I think you don't need to push that word quite so far away from mainsteam culture. It's perhaps even a little patronizing to mainstream culture? And I think that if we are ever going to overcome CP Snow's Two Cultures problem then making little gestures like this in the right direction is actually important; especially from people like you and me.

Yes, but for such a significant contribution to a huge project it's good etiquette to squash on your own before submitting the PR. (Not that it means the PR shouldn't be reviewed and accepted.)

Honestly, I frequently do this for my own personal projects since I'm lazy, but if I'm submitting something to a big open source project I always clean it up first.

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