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Discussion on: 10 Reasons NOT to use Go for your next project

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valeriavg profile image
Valeria Author

I'm sorry I'm not sure I'm following.
What is a proper exception handling in your opinion?

Go and Rust have a similar way of handling errors: (T,error) and Result<T, E>.
JavaScript, C++, Python and others do the try{}catch{}finally{} and try...except...finally, which causes the issues I mentioned in the post and aren't enforced in any way.

I mean sure it definitely fades in comparison to Windows'98 server argument, but otherwise looks legit :-)

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nfrankel profile image
Nicolas Frankel

Go and Rust have a similar way of handling errors: (T,error) and Result

I'm clueless if it's an honest misunderstanding or just trolling. In the former case, I'm willing to exchange and try to explain why they are completely different.

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kasvith profile image
Kasun Vithanage • Edited on

Go and Rust have a similar way of handling errors: (T,error) and Result

They are similar looking but Rust forces you to handle this Result type by considering error or it wont compile at all. (unless you use unwrap() which is basically handling it somehow).

In Go, its not forced to handle the errors. You can easily skip errors and have them pop up in production without you ever knowing

For example in here I ve skipped error handling and the program still compiles.

data, _ := os.ReadFile("/tmp/data")
// use data anyway
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But in runtime, this can panic the program without the programmer ever knowing.

In Rust, this is a different story

let data = fs::read_to_string('/tmp/data')
        .expect("Something went wrong reading the file");
// data is present always
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In here without expect or proper error handling, program wont even compile.

So in my opinion,

  • Having to handle error where it occures is a Plus point in Go, its very easy to spot an error
  • Not having a way to safeguard against skipped error handling is a fatal mistake(i know IDEs can help, but still that can lead to problems in Prod)
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codenameone profile image
Shai Almog

So I'm a Java guy. But the Go approach isn't new or novel. We've used it in C, Objective-C and many other languages. There are reasons people came to the conclusion that exceptions are the way to Go.

The error response approach works great in a 5 line demo app. You open one or two files and yes you have an error right there and don't need to catch. That's OK for simple use case which again might be fine for Go as it's meant to replace C more than its meant to replace Java.

Exception handling shines when you have multiple, complex operations and 3rd party API calls. Handling the error for every call becomes a noisy affair of testing every call or wrapping everything you can. In Java we can just move that error handling up the stack. The user doesn't care that method X or Y failed. They care that that the operation as a whole failed which is why we have generic handling.

The developer gets a stack that pinpoints the error for our use case. Java also has checked exceptions which enforces error handling. I think people hate that feature because it was over used in some cases, but it's a wonderful feature that works well for most cases.

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valeriavg profile image
Valeria Author

Try/catch approach works great in a demo app. But in a big codebase it's easy to forget what command throws and what doesn't. Catching up the stack seems like a great idea till the point you decide that some errors need to be handled in a different way and you start wrapping calls in yet another try/catch. Eventually you end up with the system where you have no idea where exactly an exception would be caught or silenced. There is a reason people came up with explicit error handling. It gives you not only freedom to choose how to handle it (perform early return, accumulate all the errors in a batch or ignore it), but enforces handling it close to the source. This allows you to make changes to the code in isolation, regardless of where you you've decided to catch errors.

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codenameone profile image
Shai Almog

That's a nice reuse of my statements ;-)

Unfortunately this isn't correct.

Try catch came after explicitly returning an error code and response by reference. Java solved the problem of remembering what is thrown by adding checked exceptions. Pretty much every framework has generic fallback error handling so nothing is lost. Instrumentation, diagnostic and debuggers all support exception handling very well and make working with it super trivial.

Large code bases often added "fake" try/catch semantics to languages that had no business doing this e.g. C and C++ before it became part of the language. In C++ it always sucked because it needs a GC to work and yet it was added because the value is so obviously apparent.

Try/catch maps to hardware capabilities very well and can be handled very efficiently without adding multiple branch statements. Don't say "the optimizer will remove this"... It can't do that as well.

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mxqz profile image
mxqz • Edited on

Handling the error for every call becomes a noisy affair of testing every call or wrapping everything you can. In Java we can just move that error handling up the stack. The user doesn't care that method X or Y failed. They care that that the operation as a whole failed which is why we have generic handling.

This is exactly what Go wants to avoid: Propagating an error up to a caller that has nothing to do with the actual error. Go wants you to handle errors immediately where they occur.

Other than that, your approach comes with a problem:

int myFunction() throws Exception {
    int a = calculateThis();
    int b = calculateThat(a);
    int c = calculateThose(a, b);

    return calculateResult(a, b, c);
}
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One of those functions throws an exception. Which one?

I've been a Java Developer myself and think that Exceptions are a good, but far from perfect approach. Rust does this better, and Go does it more verbose but also more explicit.

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codenameone profile image
Shai Almog

The one the stack trace points at. You would literally see the name of the problematic function and the line number in the stack. There's no chance that you will accidentally "forget" to log an error properly. No discipline required by the developer.

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valeriavg profile image
Valeria Author

As far as I know there are several types of exceptions in Java, we are referring to the ones that are not possible to check at compile time. Web applications deal with a lot of user input. Bad, malicious, unfiltered user input. That means that parsing a JSON string would fail, that some arrays would come with unexpected lengths and so forth. Go is made for web and there is no surprise it was designed this way, if you think about it. You don't want an HTTP server to hang the request, crash and restart, because someone sent some hacky request. You want to send a proper error response to the user. And often, when it comes to database issues, you also want to obfuscate the actual errors to avoid leaking your schema. With try/catch you need to either wrap every single call with it or create some horrendous upper level wrapper.

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codenameone profile image
Shai Almog

The most popular framework for Java developers (by far) is spring. It lets you define exception handlers and comes with default ones that would show the right response error if an exception makes it all the way up.

In Go you will either crash or completely miss the error (in case you didn't check) at which point the failure can cascade to something worse.

Try/catch is the exact opposite of wrapping every single call. I'm assuming you saw horrible code from people who just don't know how to use exception handling. E.g. In Spring boot I can define the exact exception types at the top level and then just throw whenever I want in the code. This will translate to the right error code to the user with all the details embedded into the response seamlessly. You can write any code you want and don't need to "deal" with errors for the most part. This is easy, efficient, maintainable, secure... Literally no downsides when compared to your approach.

My guess is that you saw some horrible try/catch nesting some novices do sometimes especially for older Java code where close() used to throw an IOException and we didn't have try with resources. The syntax is MUCH better now and the powerful capabilities you can layer on top of this (tooling, tracking etc.) is at a completely different level.

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valeriavg profile image
Valeria Author

You are missing the point. You CAN'T miss an error in Go. You are forced to do something about it. If you chose to ignore it, you do it at your own risk this way:

result, _ := doSomething()
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You need to handle the error explicitly. Go won't compile if you do this:

func doSometing() (int, error){
 return 42, nil
}

func main(){
// won't compile, you need to handle the second parameter
 result:= doSomething()
}
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And you are forced to write your functions this way, because the whole standard library is written like this.
You don't need a framework for it, you don't need discipline, you don't need to remember and thus you can concentrate or just writing the code.

And if you DO want try/catch "exceptions" you can recover from a panic:

// https://gobyexample.com/recover
package main

import "fmt"

func mayPanic() {
    panic("a problem")
}

func main() {

    defer func() {
        if r := recover(); r != nil {

            fmt.Println("Recovered. Error:\n", r)
        }
    }()

    mayPanic()

    fmt.Println("After mayPanic()")
}
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That's the whole point. Go produces fast apps, clean code and compiles fast. And Go alone is enough, you don't need a framework or even a third party library to build at HTTP server.

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codenameone profile image
Shai Almog

I hope this is an enjoyable debate to you. I don't want to come off "trollish" as in "my language is better than yours" sort of way. I think Go has a lot of interesting strengths, I just think the lack of exceptions isn't one of them. If this debate feels "iffy" let me know and I'll delete my comment with no hard feeling ;-)

You can miss an error in the same way you can miss handling an exception in Java. Miss an if or don't do a proper return when an error occurs and let it cascade. You're forced to call into the standard library like that but third party APIs don't need to follow that convention. Just like 3rd party Java APIs often convert checked exceptions to runtime exceptions.

Panic isn't try/catch. It's setjmp + longjmp. That's not practical at scale.

Go produces fast apps

So does Java, Rust and even C++. That's not a big deal.

clean code

We can debate that. I think that code that has to check for errors all the time is funky but as you clearly said, you disagree.

compiles fast

So does Java and most languages nowadays.

And Go alone is enough, you don't need a framework or even a third party library to build at HTTP server

This is a pretty bad claim. Your presenting lack of choice and diversity as an advantage?

Notice that Spring isn't an HTTP server. It's an application engine that includes everything from IoC onward and integrates dynamically with dozens of frameworks. That's a strength IMHO.

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mxqz profile image
mxqz

The one the stack trace points at. You would literally see the name of the problematic function and the line number in the stack. There's no chance that you will accidentally "forget" to log an error properly. No discipline required by the developer.

Absolutely. However, when reading/browsing the source code, you don't know which methods throw which exceptions, where those exceptions are handled and what the control flow looks like. You immediately see what's happening when looking at Go (or Rust) source code - the control flow is very explicit and obvious. But this probably is a matter of personal preference.

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valeriavg profile image
Valeria Author

Oh my, no this isn't an enjoyable debate.
Your claims are based on your subjective perception and, if I'm honest, quite disconnected from the reality.
Go promotes diversity and code sharing much better than a lot of languages. You can literally use any repo as a package. Therefore there isn't a monopoly over http like it is in case of Spring, but plenty of options, yet you are not obligated to use them.
Leave the comments, there was a lot of examples readers might find useful, which was ultimately the goal of the article.

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ecyrbe profile image
ecyrbe

I'm programming in rust nowadays and like Go, error handling is explicit.
Rust has syntactic sugar with the "?" keyword to forward errors and let the caller handle the error. Does Go have the same feature ?

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valeriavg profile image
Valeria Author

Nope, Go doesn't have that.

Both Rust and Go use the return value as an indicator of an error and enforces handling it on spot, but that is the only similarity.

Go's error interface is defined by the presence of an Error() string method and cannot do anything, but becoming a string.

Rust's Result has handy methods like unwrap or expect, along with the sugar.