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> For a large change, I don’t want to do a “diff review”, I want to do a proper code review of a codebase at a particular instant in time, paying specific atten

• dylukes 3y ago
  > In my book a general code review is simple sanity check by a second pair of eyes, which can result in suggestions to use different API or use an API slightly differently. This is an impoverished view of code review. Code review is a principal mechanism for reducing individual code ownership, for propagating conventions, and for skill transfer. A good code review starts with a good PR: one that outlines what its goals were and how it achieved them. First item on a good review then: does the code achieve what it set out to do per the outline? Second: does it contain tests that validate the claimed functionality? Third: does it respect the architectural conventions of the system so far? Fourth: is the style in line with expectations? Fifth, and finally: do you have any suggestions as to better API usage? A code review that is nothing more than a sanity check is useless and could have been done by CI infrastructure. Code review is a human process and should maximally take advantage of the things only humans could do. Leave the rest to machines. An implicit question in several of the above is "will this set a good example for future contributions?"
  • phillipcarter 3y ago
    As a counterpoint, individual code ownership can be a fantastic model too. It lets engineers specialize and takes advantage of social systems that form naturally anyways. I’ve not personally seen group ownership work well, and in practice, it’s still an individual who knows a given area the best.
    • sam_lowry_ 3y ago
      > reducing individual code ownership I am now working in an organization that is set up to reduce code ownership, and they struggle to attract talent, although pay is good and work is fulfilling. How do they do reduce individual code ownership? Horizontal integration. Developers code, analysts design DB structures (at least nominally), project managers set up meetings. Different silos exist for CICD, cloud roles, core teams. There are vetting committees everywhere that have the last say on the libraries used and the nitty-gritty details of REST APIs and naming. It exhilarating to start projects, then see them degrade inevitably into corporate monstrosities.
      • diarrhea 3y ago
        > an organization that is set up to reduce code ownership, and they struggle to attract talent These might not be related though? > work is fulfilling > It exhilarating to start projects, then see them degrade inevitably into corporate monstrosities. What you describe does not sound pleasant. So it's not fulfilling after all?
        • sam_lowry_ 3y ago
          Projects are fulfilling because they have public utility. The no individual code ownership policy is hard to bear for inquisitive minds, though. Thus the talent shortage.
          • ilyt 3y ago
            You assume projects are fulfilling because they have "public utility" (whatever the fuck that means). That's your assumption, not objective fact. I would not work on boring ass project with cripping management problems and think that's fulfilling. I assume you have recruiting problems because most people share that sentiment. People like to work on interesting stuff without much office politics, that is "fulfilling" to them, even if outcome is app that would be "boring" to the outsider.
  • friendzis 3y ago
    As I have said - every team is different :) In response to your first point I guess things really depend on where you store PR metadata and how ephemeral/permanent it is. Some teams store that information in the ticket, some fill implementation notes with change request, some add that to the PR, some discuss in their standup (or similar) meeting. Regarding 2-3, you are right, I just lumped them all under umbrella term. Maybe we could use terms like "PR review" and "code review". The former is a shallow LGTM check, while the latter may involve code checkout, poking around, architectural discussions, pair/team programming and so on. In my book they are entirely different beasts and web tools are geared (not without justification) towards the former, where both types of diff should serve the purpose.
    • yarekt 3y ago
      To me this happens naturally, Looking at the diff first, if I know the codebase well might be enough to get a sense of the changes, or at least understand their isolation. However, as soon as I start to feel that I don't fully understand the implications, I quickly check the branch out and poke in an editor. OP is right though, if the "check out in editor" workflow was much smoother (than quick web view) I would prefer to always do that
  • jeffreygoesto 3y ago
    Well put. I'd like to add that individual code ownership must not necessary be lived as a loner sitting on that code. Being an owner means hatching, keeping clean and also knowing when getting help is beneficial. Accepting your bias and asking for a look from a different perspective is not getting rid of or dispersing ownership in my view, it is a central part of it. Often this includes getting feedback if that change can make problems outside the feature implemented or in the future, like introducing dependencies that cost more in total than they help locally.
  • crdrost 3y ago
    I go back and forth on this. On the one hand, I really like constant deep feedback. I really like the consistency benefits of having another person say “that’s too much, I find that unreadable.” On the other, I have now been at a lot of places where it was very hard to get my code reviewed, latencies of days and sometimes weeks if folks are in a particularly heinous crunchtime... And then when it does get reviewed, the stuff that I worked really hard on to get the right speed or to properly centralize cache invalidation... Suddenly someone is like “I would have done it from this other approach” and you have no idea whether it's tractable or not. While I have never been at a place that did this, I have in my head the idea that the code should be an unfolding collective conversation, kind of like when folks are all collaborating on a shared Google Doc, I see that you are editing this section and I throw in a quick comment “don't forget to add XYZ” and then jump to a different part that I won't be stepping on their toes with. So the basic idea would be to get everybody to merge to `main` like 2 or 3 times a day if possible. In that case code review really is just “make sure this doesn't break the build or break prod, everything is behind a feature toggle, if I don't like the design I will comment on the code near the design or sketch a proof of concept showing that my approach is superior in clarity or speed or whatever”... Nobody ever takes me up on this culture shift it seems.
    • yarekt 3y ago
      This is called Continuous Integration, and its a shame that the term got nicked to now mean "that thing that builds our PRs somewhere". The idea was that everyone pushes to main all the time, which basically reduces integration time to 0, as everyone is doing it every couple of minutes on big teams. After a while you learn how to not step on people's toes (Introduce new classes incrementally, use docblocs documenting class' intent, rather than just current functionality) I too find that its basically impossible to suggest switching to this workflow, given the weight of all our existing tools. They are so easy to setup, and most come for free (Azure Devops/Pipelines thing) that going off the track is just unthinkable.
      • eru 3y ago
        Everyone committing to the main branch all the time sounds like a nightmare to me, to be honest. I would probably seriously consider quitting if this was forced on me. (Or rather, I would probably just run on my private git copy, and only pull every once in a while, and ignore that the main branch always changes.) When / how do you do code review in your suggested workflow?
  • mannykannot 3y ago
    This is an ideal (if not utopian) vision of software review (though please let's handle style checking automatically already!) It implicitly requires, however, such a thorough examination of the code that diffs would seem to be an irrelevant distraction. In practice, however, starting from the changes in a system that was previously working well enough is a very effective way of focusing limited human attention on where the problems are likely to be, optimizing for error detection with limited resources over the broader knowledge-dissemination goals espoused in this approach. If we are going to use diffs, then this brings us back around to the topic if the article. Personally, I find having any form of diff embedded in what I am trying to understand just makes it harder to follow, so I move the diffs onto a secondary screen and use it as a guide and reference to what has been changed. The author of the article seems to want the same, but the mock-up is somewhat misleading, as it only has substitutions and additions. Where something is removed or refactored to another place, the two views will no longer line up as depicted here.
  • ozim 3y ago
    Code style check should be automated. I do not accept discussions on style in PR in my team besides pointing out obvious deviations which should be automated. Discussion on that should be way before making PR. Architectural changes/discussion should be discussed by developers way before PR on slack or in a call. Most features should not change architecture and team should make effort to align architecture all the time at least before someone makes PR. Unless of course PR is PoC to showcase approach.
  • mattarm 3y ago
    Those are good things to consider in review, but I maintain that the answer might be "no" to one or more of those questions and still be acceptable. I'm old enough to have worked in the pre-code-review era. Things were fine. People still learned from each other, software could still be great or terrible, etc. It wasn't appreciably worse or better than things are today. > An implicit question in several of the above is "will this set a good example for future contributions?" Which in my experience can be an almost circular requirement. What do you consider a good example? As perfect as perfect can be? Rapid development? Extreme pragmatism? The more experienced I get, the less I complain about in code review, especially when reviewing for a more junior dev, and especially for frequent comitters. People can only get so much out of any single code review, and any single commit can only do so much damage. Put another way, code review is also about a level of trust. Will the committer be around next week? Are they on the same team as me? If yes, give them some leeway to commit incremental work and make improvements later. Not all incremental work need occur pre-commit. Mention areas for improvement, sure, but don't go overboard as a gatekeeper. Things are obviously going to be different when reviewing code from what amounts to a stranger on a mission critical piece of code, etc.
    • PH95VuimJjqBqy 3y ago
      > Put another way, code review is also about a level of trust. Will the committer be around next week? Are they on the same team as me? If yes, give them some leeway to commit incremental work and make improvements later. Not all incremental work need occur pre-commit. Mention areas for improvement, sure, but don't go overboard as a gatekeeper. I think this is very important, especially the part about incremental improvement. too many see development as laying concrete where it has to be perfect rather than as an ongoing process. and personally the only thing I find PR's good for is ensuring jackasses aren't doing stupid shit. And by stupid shit here I mean things like using floats for currency (I caught that w/i the last year), things of that nature. But my preference is to work with people I can trust and at that point I don't give a crap about a PR or a code review.
  • kazinator 3y ago
    This is why you should insist on a changes being reviewed by at least two pairs of eyes. Someone responsible for that area of the code might raise those kinds of objections. Someone who is more of an outsider can focus on other problems. E.g. I'm kind of a human compiler; I can say things like, you have undefined behavior here, in a completely unfamiliar code base where the maintainer of that might miss the issue, too busy pointing out that it doesn't respect architectural conventions, and is not tested.
• lvncelot 3y ago
  I agree about what to expect from a code review - but for me, certain ways of working need to be in place for this to function properly. A code review is the "last line of defense" (well, disregarding CI), but in the teams I've worked in, that meant that the general idea of what the PR is introducing has been discussed by multiple people at that point. (This could be either a pairing session, an in-depth explanation, or just a coffee chat, depending on the complexity) This way the PR isn't about reviewing the general strategy (splitting off a new module, introducing a huge dependency, reworking the API surface), but just about reviewing the tactics used to implement that strategy. Without the communication beforehand, doing only sanity checks on parts of the code in isolation does run the risk of fracturing code ownership. ("What's that module doing?" "Beats me, ask bob") That all notwithstanding, I like the author's idea of what a diff view should look like, regardless of the "mode" of reviewing.
• robertlagrant 3y ago
  The problem is that this isn't a great way to catch areas of the codebase that should've been updated, but weren't.
• lapcat 3y ago
  In my book, superficial code review produces only superficial results. This is how so many bugs get shipped despite the ubiquity of code review. Call me crazy, but I've always approached code review from the standpoint of a tester: I build and run the code, see whether it does what it's supposed to do, look for possible weak points, and try to break it. The diffs are the beginning rather than the end. They show you where to start poking around in the code. The proof is in the pudding, though. You might respond, "That's what testers are for, not engineers." But who can test better than someone who understands the code and knows exactly where to look and what to look for? I know this attitude puts me in the minority. The majority of engineers seem to have an inborn horror at the prospect of, gasp, manually running code. (They're also strangely averse to using debuggers.) They'll do anything in the world and write vast infrastructure to avoid it. Automate all the things! But in my view, automation is just more possibly buggy code. Who tests the tests? Quis custodiet ipsos custodes?
  • eru 3y ago
    Automated tests aren't so much to make sure that the test you just wrote works. You are right that manual testing can do that better sometimes. Automated tests are so that the code you just implemented still works next months, when lots of other people have made unrelated changes, and weren't always aware of the interactions with other parts of the code. The automation is important, so that the tests get run, even when people forget or are under time pressure.
    • lapcat 3y ago
      To be clear, I'm not against automation. What we do for a living is write code, so when I say "automation is just more possibly buggy code", I'm not opposed writing more code (though I am opposed to overengineering). My point is that I don't place all of my faith in automated tests, and I'm not opposed to rolling up my sleeves, getting my hands dirty, and doing manual labor. Manual labor can be tedious, though, and that's probably why a lot of engineers hate it.
      • samus 3y ago
• delaaxe 3y ago
  I'd call the latter an audit
• jerf 3y ago
  I think you have some good truths in your post, but I also think they're rendered somewhat irrelevant by the fact that a "diff review" is, in my repeated and frequent experience, simply incomprehensible. I can't do any review with an incomprehensible mass of red and green lines interspersed with each other. It's not a useful view of the code, or at least not a useful primary view. I push through and do it anyhow, because this is one of those "they're not paying me to have an endless party" sort of things. But I completely 100% agree with the author that it is not a very useful view.
• apocalyptic0n3 3y ago
  > unless the person doing the review is some sort of principal engineer mostly responsible for the code at large [..] In my book a general code review is simple sanity check by a second pair of eyes I don't necessarily disagree with you, but I don't agree either. A typical workflow should be: 1. Engineer writes code 2. Engineer does manual and automated testing to verify things work correctly 3. Engineer commits, pushes, and creates a PR/MR 4. CI runs test suite 5. Another Engineer reviews PR/MR 6. Approval causes merge which causes deployment to staging 7. QA 8. UAT 9. Repeat steps 1-8 until everybody is happy In this, we need to place checks on #1 and #2. In my eyes, QA and UAT are superficial reviews/sanity checks on #2. #3 is a check in #1. However, it relies on A) previous engineers implementing good tests and B) the current engineer doing the same. This means trusting people are doing the right things, but a Review implies you don't completely trust that. #5 is a check on #3 and #1. They're essential. Having a full understanding of what the code looks like is more important in my mind than what was actually changed. The changes don't show how other code is interacting with those changes (which should be, but isn't always, captured by unit tests). That's why I think the article author's preferred view is ideal. In fact, that's roughly what I work with when reviewing without realizing it (diff in GitLab/GitHub/Sublime Merge, code in JetBrains where most of the review happens).
• codemac 3y ago
  Most of modern technology company culture has strayed too far from doing more formal processes for managing development. By not having a basic process for defects, features, etc, every engineer has to make up and invent the process for how they will ship their feature through collaboration. In most cases this ends up with doing little to nothing, with code review being the only form of collaboration on the topic that is in any meaningful detail. So we're left trying to stuff all possible interventions into a single moment.
• gumby 3y ago
  For most changes I want more context than -c provides, because I see that your change is syntactically correct, but semantically, was your change from < to <= appropriate? I need to see the definition of the things you're comparing to. Often -c is enough, but not always. I don't believe you can make a hard and fast rule. I think all you can really do is have a diff that allows you to 'jump to definition' or 'list callers', just like you can when looking at the code itself.