DEPRECATED

Shadow catching is now part of go tool vet

go tool vet -shadow=true ./

Does what you want now. Make sure to run it separately from the standard go vet So you probably want:

go tool vet ./
go tool vet -shadow ./

In your relevant configuration.

Note that it does not ignore error types. But this is more strict anyway.

---

go-nyet

More aggressive go vet

Why?

I've been bitten by too many bugs caused by the shadowing of Go variables within subblocks. The time has come to end them once and for all.

What does it do?

It checks for shadowed variables anywhere they appear in the code. Helpfully, it also type checks these variables and ignores anything of type error. This is because it's very common practice to shadow err and, well, shadowing error typed things hasn't hurt me nearly as much in the past.

It also checks for clobbering of variables that occur that aren't technically shadows. Eg:

package main

import "os"

func main() {
    f, err := os.Open("")
    f, err = os.Open("")
    println(f, err)
}

Other aggressive checks may come in the future.

How do I get it?

go get github.com/barakmich/go-nyet

And run

go-nyet ./...
# or
go-nyet subpackage
# or
go-nyet file.go

In the root of your project. If it complains about packages, you may need to go install them first.

Still working out the kinks, but give it a shot.

License

BSD