go-vet.md

tags: go, lint

go vet

The go vet is the builtin compile time code checking tool. It likes eslint of js.

Some tips

- go vet is not forcible, some ide may help to run it automatically
- go vet is not for styles, it is more about real errors

example

For following code, you can build and run it without problems. But if you run go vet it will give you some notices.

func main() {
	a := sync.Mutex{}
	arr1 := []int{1,2,3,4}
	for i,v := range arr1 {
		go func() {
			fmt.Println(i,v)
		}()
	}
	fmt.Printf("a is %v\n", a)
}

prog.go:15: loop variable i captured by func literal
prog.go:15: loop variable v captured by func literal
prog.go:18: call of fmt.Printf copies lock value: sync.Mutex

It warns you that the result of closure in loop may not be what you want. And Mutex cannot be copied.

inside

The go/src/cmd/vendor/golang.org/x/tools/go/analysis/passes has a lot of checks, like loopclosure and copylock which showed above.

go vet will check all of them.