Label at the end of a block is not a whitespace (nor comment)

[olibre]

Simplified version of my code:

for _, x := range a {
	if x == y {
		goto SKIP // do not append
	}

	clean = append(clean, x)
SKIP:
}       // block should not end with a whitespace (or comment)

I think wsl considers the label SKIP as a whitespace (or comment)...

[bombsimon]

I don't know why you would do this in golang though, it seems lika a pattern from BASIC och batch scripting. Maybe that says more about me but I thought I've seen my shared amount of Go code and this pattern never occurred to me. In your example I would just use continue to go to the next iteration.

for _, x := range a {
    if x == y {
        continue
    }

    clean = append(clean, x)
}

If I wanted to continue in nested loops I would label the outer most loop and continue that one like so:

OUTER:
    for range a {
        for _, x := range b {
            if x == y {
                continue OUTER
            }
        }
    }

If I had code that wasn't related to this loop that I wanted to skip i would use return. If I had code after this loop that I wanted to scope and more code after that that I wanted to execute I would break this function into several functions since that sounds like it's doing way to much.

I tried to Google and see when a good use case for goto in golang would be and I found some references to stdlib. Those however is never to go to the end of a scope and especially not to the end of a function.

So basically this is not intended but since I want this linter to enforce good practices not only by adding whitespaces but to think of what's a good way to tackle an issue and improve readability I don't see this as something that I do want to support. Ending a scope with a label just to be able to goto it is not something I want to encourage.

Obviously this is my personal opinion so feel free to argue why you think this is a good pattern and what the benefits over the other control flows such as break, countinue and return this would have.

[olibre]

Thank you for your excellent advise 👍
My new code:

func removeDuplicates(a, b []string) []string {
	clean := []string{}

OUTER:
	for _, x := range a {
		for _, y := range b {
			if x == y {
				goto OUTER // do not append
			}
		}

		clean = append(clean, x)
	}

	return clean
}

Note: Coding in Go is new for me 😉

[olibre]

Sorry for the four PR: I was thinking I was editing my own forked of your Git repo!

[Oppodelldog]

I agree with @olibre, a jump label is not a whitespace and should not be treaten as if it was.
@bombsimon do you know what is the intention of doing so? Isn't "good coding practise" out of scope for a whitespace linter?

[bombsimon]

@Oppodelldog yep, you’re right. This should not be a part of wsl so it should be fixed, that’s why I left the issue open. This lintet should not warn about this! PRs welcome! :)

[Oppodelldog]

@bombsimon I'll give it a try in hacktober. ;)

[bombsimon]

Merged in golangci/golangci-lint#1750, will be available in next release.