Open
Description
go tool vet --shadow returns a false positive when the variable being shadowed is declared from the return of an exported user function from another package. That's a mouthful, so here's some code:
./other/other.go:
package other
func Foo() (int, error) {
return 0, nil
}./shadow_test.go:
package shadow
import (
"errors"
"testing"
"github.com/tamird/shadow/other"
)
func foo() (int, error) {
return 0, nil
}
func TestVetShadow(t *testing.T) {
// Local varibles: this passes.
// a, err := "a", errors.New("Foo")
// Function from same package: this passes.
// a, err := foo()
// Function from standard library: this passes.
// r := &bytes.Buffer{}
// a, err := r.Read(nil)
// Function from different package: this triggers shadowing warning.
a, err := other.Foo()
if err != nil {
}
if _, err := other.Foo(); err != nil {
}
b, err := "b", errors.New("Foo")
if err != nil {
}
_, _ = a, b
}The comments in the code describe the problem. Use other.Foo() and you get a false positive; use any of the others (local function, local variables, exported method from the stdlib) and the warning goes away. Weird!
All the code is also available here: https://github.com/tamird/shadow
cc @mberhault