this is a real problem in go, very easy to have bugs when working with channels and the way it handles errors etc.
TIL: HN doesn't like writing tests. The downvotes on this are hilarious. "Job security" ¯\_(ツ)_/¯.
You stay away from something you don't understand after 10 years of working with it? What kind of logic is that? Channels aren't magic.
Subtle bugs in what? Have you considered that maybe you have bugs because you aren't writing tests?
If you aren't unit testing that stuff, then how are you able to fix/change things and know it is resolved?
My experience is that I built a binary that had to run perfectly on 30,000+ servers across 7 data centers. It was full of concurrency. Without a litany of automated tests, there is no way that I would have trusted this to work... and it worked perfectly. The entire deployment cycle was fully automated. If it passed CI, I knew that it would work.
It wasn't easy, it took a lot of effort to build that level of testing. But it was also totally bug free in production, even over years of use and development.
Perhaps a less defensive posture might invite more discussion.
I can't think of a single production problem that can't be replicated with a unit test. If you're seeing a problem in production, you need to fix it. How do you fix it? You write a test that replicates the problem and then fix the code, which fixes the test.
First you claimed before that unit tests will catch your subtle concurrency bugs before they happen, and that's just not often the case. They are subtle, might involve many systems and weird edge cases and often don't get caught BEFORE they happen. Of course anyone can write a test to replicate the problem after seeing it in production and spending hours/days debugging it.
More importantly, "Write comprehensive tests" is technically a strategy to avoid any bug ever. You can tell C programmers not to segfault by writing comprehensive tests but that doesn't negate the point that the language makes it easy to write segfaults. "Write more tests" is not a rebuttal to saying C makes some classes of errors easy to write. Writing comprehensive tests often takes a lot of time, is often not prioritized by companies, and is especially hard with distributed systems, concurrency, mocks and complex applications. If we just said "git gud noob" in the face of error prone and difficult abstractions, we might as well all be using assembly.
I guarantee you I won't be using your product. Just something to consider.
Regarding my company, I respect your decision, but I hope that if our paths cross again, I might have the opportunity to change your mind through actions that demonstrate the value we provide to our customers.
Perhaps bringing it down a notch could help you connect with others’ perspectives as well.
"very easy to have bugs when working with channels and the way it handles errors etc"
If you've done some programming you'll find this to be true. You have to think a LOT harder if doing concurrency, and you generally have to do a lot more tests.
Go - WITHOUT that much testing, is often surprisingly error free compared to more dynamic languages just out of the box both language side and how a lot of development happens. Python by contrast, you can have errors in dependencies, in deployment environment (even if code is fine), based on platform differences (tz data on windows), and plenty of runtime messes.
Channels are not as default safe / simple after compile as a lot of other go.
Try programming without channels in go and this may become clearer.
I don't blame Go. It's an inherently difficult problem space. As a result, testing isn't a trivial job either. I wish it was.
Again with the HN downvotes, hilarious. People really hate the truth.
Think about it: If you're writing code and don't realize that it can deadlock under certain conditions, how are you going to realize that you need to test for whether it deadlocks under those conditions? If you're writing code that interpolates one kind of string into another and don't realize that you may have created an XSS vulnerability, are you suddenly going to gain that insight when you're writing the tests?
I'm not arguing that you magically predict everything that's going to happen. But, without those tests and the culture of writing tests and writing your code to be testable, you're screwed when you do have bugs in production.
That's nice, but it's far from "knowing your code works". When code works, it doesn't burn you in production.
How do you know your code is going to work in production before you got there? You wrote tests.
You know your code is going to work in production before you got there not because you wrote tests but because you thought about what it means for your code to work in production and then came up with a plan to generate the required confidence that it actually will work in production. And, for any nontrivial system, tests can only satisfy part of that plan.
The goal isn't to have well-tested code. The goal is to have code that you can easily be confident will work as intended. And testing is only good at establishing some kinds of that confidence. For the other kinds, such as confidence you're not going to launch a bunch of security disasters or concurrency landmines, you need to do something else: types, proofs, correctness by construction, model checking, and so on.
I wrote about this idea almost twenty years ago: https://blog.moertel.com/posts/2006-10-10-unit-testing-is-a-...
I elaborated in a later post: https://blog.moertel.com/posts/2012-04-15-test-like-youre-be...
That you seem to believe otherwise is probably why a lot of people are having trouble with your claim that that world doesn't need better concurrency abstractions, just more tests because "if you write comprehensive unit tests, it is not easy to have bugs in golang."
All the negativity (downvotes) has come from people who are trying to argue that writing tests doesn't solve the problem of bugs. The same people who don't write a lot of tests AND have a lot of bugs. ¯\_(ツ)_/¯
I write a lot of tests and I don't have bugs. I have decades of experience and millions of lines of code, with this simple fact. I know it is true, at least for me.
I don't know what else to bike shed here other than the constant downvoting by people who somehow don't believe my claim. The loss in karma doesn't bother me, I know I'm right on this and it appears as though the only people who disagree with me are the same people who don't write tests (and have a lot of bugs).
golang is a relatively simple language. It is why I like it so much. Occasionally there are somewhat difficult things to reason about, but if you write golang code that is easily testable (and this requires thought and planning), then my experience is that even the "harder" channel/goroutine code can always be tested in one way or another.
For the record, I write lots of tests, and don't have bugs. I even wrote a testing framework. Nobody is arguing that writing tests is dumb. The pushback is on your insistence that writing tests is all you need:
> All the negativity (downvotes) has come from people who are trying to argue that writing tests doesn't solve the problem of bugs.
Writing tests doesn't solve the problem of security bugs. Writing tests doesn't solve the problem of concurrency bugs. Writing tests to prove your code is bug free in those cases is expensive and error prone.
People who care about these things know to go beyond testing when testing isn't enough. That's why things like model checkers exist.
Nobody is arguing that tests are dumb. The argument is that if writing tests is all you're doing to get the bugs out of your code, you probably aren't very effective at preventing certain classes of problems.
For instance: Show me the tests you'd write to prove your software doesn't have XSS vulnerabilities.
I'd have tests around the code that renders 3rd party user input and integration tests for the display of the data.
I've built some of the most heavily trafficked websites on the planet (porn), with user input (comments) and have never had an XSS issue.
If you can't show me the tests you'd use to prove you don't have XSS problems, it's hard to believe that your tests are effective at preventing XSS problems.
> I've built some of the most heavily trafficked websites on the planet (porn), with user input (comments) and have never had an XSS issue.
Right, because the gold standard for proof in the security field is "we never had [read: noticed] an issue."
You're also being absurd. We started this talking about golang testing and it has somehow gone off the rails to me having to prove things to you about XSS? Come on, what is with the hostility? Is this how you treated people while working at Google?
I'm not sure how to meaningfully distinguish the two here. I'm saying it takes extra effort, not denying that it's my job. It's non-trivial, that's all I'm trying to say.
> How do you fix a production bug without breaking something else? You write tests so that you know your code works.
Of course, you're right. Sometimes writing the tests can be harder than writing the code, though.
which misses the point of the OP.
Technically you may be right, but it’s not a helpful viewpoint. What the world needs are abstractions that are easier to understand and program correctly, not assertions that everyone else is doing it wrong and just needs to be smarter/work harder.
If you want an analogy, I'm arguing that a condom helps prevent STD's and unwanted pregnancies. It isn't perfect, but at least it is better than not wearing a condom at all. Nobody loves wearing a condom, but we do it cause it is the right thing to do.
This is where other forms of software testing come into play. Such as integration tests.
You write tests to cover edge cases. If you miss one, you write more tests when you come across them. This isn't magic.
…before such point you have hard to find bugs in your software.
And that’s the crux of everyone’s argument against your “just write better code” fallacy ;)
> This isn't magic.
No it’s not. That’s why people disagree with your assessment that unit tests can catch every type of bug.
If unit tests really were that magical then we wouldn’t need for other methods of tests.
I mean, do you even know what a unit test is? It’s meant to be self-contained but the problem with multithreaded code is that you can start to introduce side effects that happen outside that functions scope.
I’ve got exactly that issue right now calling OS APIs from cgo. Some of those APIs (particularly with SDL) are very thread sensitive and you cannot unit test for that because the problem lies outside that functions scope. So the only way to test for that is with e2e or integration tests instead.
I also never said unit tests were the ONLY tests.
Nobody disagrees with your point about the importance of unit tests. But the way you present that point is more than a little naive (and that’s the polite way of putting it).
Trying to handwave and say that your code is too complex to be tested is very strange to me. Maybe take a step back and ask yourself why your code is too complicated to test. Maybe refactor it a bit to be less complicated or more easily testable.