Error variable naming #9

Opendmitshur opened this issue 8 years ago

dmitshur commented 8 years ago · edited

Do this:

// Package level exported error.
var ErrSomething = errors.New("something went wrong")

func main() {
	// Normally you call it just "err",
	result, err := doSomething()
	// and use err right away.

	// But if you want to give it a longer name, use "somethingError".
	var specificError error
	result, specificError = doSpecificThing()

	// ... use specificError later.
}

Don't do this:

var ErrorSomething = errors.New("something went wrong")
var SomethingErr = errors.New("something went wrong")
var SomethingError = errors.New("something went wrong")

func main() {
	var specificErr error
	result, specificErr = doSpecificThing()

	var errSpecific error
	result, errSpecific = doSpecificThing()

	var errorSpecific error
	result, errorSpecific = doSpecificThing()
}

For consistency. See https://go.dev/talks/2014/names.slide#14.

storozhukBM commented 6 years ago

specificErr seems more reasonable.

dmitshur commented 6 years ago · edited

@storozhukBM I guess both are fair style choices. I wanted to pick one, so that all my code would be consistent. specificError seemed more natural to me: if the first word is long and written in full, might as well write "Error" in full too.

storozhukBM commented 6 years ago · edited

@shurcooL I always use specific names for errors, so compiler can help me to detect not checked ones, as not used variables.

dmitshur commented 6 years ago

That's an interesting approach. I haven't seen that before. Thanks for sharing.

I know there are tools such as errcheck and staticcheck that can help detect unchecked errors even if you reuse the same err variable.

QuantumGhost commented 2 weeks ago

IMO, use const for exported sentinel errors is much better.

type sentinel string

func (s sentinel) Error() string {
	return string(s)
}

const (
	ErrorSomething sentinel = "something wrong"
)

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