loopvar

loopvar is a linter that detects places where loop variables are copied.

cf. Fixing For Loops in Go 1.22

Example

for i, v := range []int{1, 2, 3} {
    i := i // The loop variable "i" should not be copied (Go 1.22~ or Go 1.21 GOEXPERIMENT=loopvar)
    v := v // The loop variable "v" should not be copied (Go 1.22~ or Go 1.21 GOEXPERIMENT=loopvar)
    _, _ = i, v
}

for i := 1; i <= 3; i++ {
    i := i // The loop variable "i" should not be copied (Go 1.22~ or Go 1.21 GOEXPERIMENT=loopvar)
    _ = i
}

Install

go install github.com/karamaru-alpha/loopvar/cmd/loopvar
go vet -vettool=`which loopvar` ./...