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Comment by lazyasciiart | Hacker News Reader

> This is planning issue, if you correctly size tickets you aren’t going to end up in messy situations as often.

No, it’s “this refactor looks very different to the original code because the original code thought it was doing two different things and it’s only by stepping through it with real customer data that you realized with the right inputs (not documented) it could do a third thing (not documented) that had very important “side effects” and was a no-op in the original code flow. Yea, it touches a lot of files. Ok, yea, I can break it up step by step, and wait a few days between approval for each of them so that you never have to actually understand what just happened”.

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so, it's not just a refactoring then; it's also bug fixes + refactoring. In my experience, those are the worst PRs to review. Either just fix the bugs, or just refactor it. Don't do both because now I have to spend more time checking the bugs you claim to fix AND your refactoring for new bugs.

There are certainly classes of bugs for which refactoring is the path of lowest resistance

The most common IME are bugs that come from some wrong conceptual understanding underpinning the code. Rewriting the code with a correct conceptual understanding automatically fixes the bugs.

The classic example of this is concurrency errors or data corruption related to multiple non-atomic writes.

And there are multi-PR processes that can be followed to most successfully convert those changes in a comprehensible way.

It'll often include extra scaffolding and / or extra classes and then renaming those classes to match the old classes' name after you're done, to reduce future cognitive load.

I'm unconvinced that adding extra code churn in order to split up a refactor that fixes bugs into a bugfix and a refactor is worthwhile

One metric I like to give my team is to have any new PR start a review in less than 15 minutes and be completed within 15 minutes. So, the longest you should wait is about 30 minutes for a review. That means teams either go "fuck it" and rubber stamp massive PRs -- which is a whole different issue -- or they take it seriously and keep PRs small to get their PRs reviewed in less than 30 minutes.

In most cases where I see responses like this, they're not surprised to wait hours or days for a PR review. In that case, it makes sense to go big, otherwise you'll never get anything done. If you only have to wait half an hour, max, for a PR review; the extra code churn is 1000% worth it.

This is where my stance is.

As a developer, I want my PRs to actually be reviewed by my coworkers and to have issues caught as a second layer of defense, etc.

As a reviewer, I effectively stopped approving things I couldn't give at least a cursory, reasonable glance (and tried to encourage others to follow suit because if we're not reviewing things, why not just push directly to main).

As a consequence, I have:

  * tried to review most things within like half an hour of their announcement
    in the shared MR channel

  * requested a pair programming session and offered to do a pair programming
    session for any large and semi-or-fully automated refactoring session,
    like running a linter or doing a multi-file variable rename
    (the pair programmer immediately comments on and approves the MR when it
    appears)

  * tried to limit my PRs to approximately 400 lines (not a rigid rule)

There were some specific instances of people not liking the "you must pair program if you're going to touch 400 files in one PR" requirement; but otherwise, I would like to think those on my team liked the more regular PRs, more people doing the PRs, etc, that resulted from this and some healthy culture changes.

I would also like to feel like the more junior devs were more willing to say anything at all in the PRs because they could follow the change.

I’ve seen this and variations done by teams to implement the metric. Usually, the “biggest” friction comes from “how do we know a PR needs to be reviewed within the time frame?” To which I always want to answer: “you have a mouth, put noises through it.” Sigh, sometimes I miss the military… anyway, toxic behavior aside, this is usually the biggest thing. I have to remind them that they go get coffee or smoke at least every hour, but rarely at the same time; so maybe then might be a good time to just do a quick check for an open PR. Or turn on notifications. Or if it’s urgent, mention it in the dev team channel.

But yeah, it’s hard to get the culture rolling if it isn’t already in place nor has anyone in the company worked with a culture like that.

I'm all for low-latency reviews, but this target seems crazy: a perfect recipe for a lot of apparent activity for little actual progress. Maybe it depends on the project, but for a lot of projects 15 minutes of review time means you basically are only going to accept trivial changes.

As it turns out, most of the work that most developers do is updating or enhancing CRUD apps. There's already a plan and an intent that just needs to be typed out.

I've found 15-30 minutes to be plenty of time to review about a day's worth of code. It's enough time to process what the code is doing and iterate over the tests, in general.

Here's a scary thought: if something small takes 15-30 minutes to appropriately process ... how much longer do *large* changes take? Can someone keep all that in their mind that whole time to comprehend and process a huge change?

And a better question, will they?

> 15 minutes of review time means you basically are only going to accept trivial changes.

Um, yes. This is 100% the point. There is no amount of refactoring, bug fixing, or features that cannot be expressed as a chain of trivial changes.

What you usually see happen is that instead of spending a week experimenting with 15 different refactors, is that an engineer opens a PR with what they think they're going to try first. Other engineers point out how they had tried that before and it didn't work; but maybe this other way will. So, they end up "working together" on the refactor instead of one developer getting lost in the sauce for a week seeing what sticks to a wall.

In essence, about the same amount of time is spent; but the code is higher quality and no architecture reviews during code reviews (which is another rule that should exist on a team -- architecture reviews should happen before a single line of code is touched).

No, I very deliberately did not describe any bug fixes.

> only by stepping through it with real customer data that you realized with the right inputs (not documented) it could do a third thing (not documented) that had very important “side effects” and was a no-op in the original code flow

sounds like the 'nightmare' was already there, not in the refactor. First step should be some tests to confirm the undocumented behaviour.

Some of your complaints seem to be about peer review ('approval'). I found my work life improved a lot once I embraced async review as a feature, not a bug.

As for 'break it up step by step' - I know how much I appreciate reviewing a feature that is well presented in this way, and so I've got good at rearranging my work (when necessary) to facilitate smooth reviews.

> sounds like the 'nightmare' was already there, not in the refactor

I admit that I am pretty allergic to people who avoid working with imperfect code.

The way I normally approach this is one big pr for context and then break it into lots of small ones for review.

I've found processes like this to work better, too. Basically, the one big pr is like building a prototype to throw away. And the benefit is it has to get thrown away because the PR will never pass review.

A PR with self-contained smaller commits would be possible as well.

Yes, though it does depend on how good the commenting system is; and, for something like that, you're still probably going to want a meeting to walk people through such a huge change.

And you'd better hope you're not squashing that monstrous thing when you're done.

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