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44package unwrap
import (
"errors"
"fmt"
"testing"
)
func ExampleUnwrap() {
e1 := errors.New("e1")
e2 := fmt.Errorf("e2 -> %w", e1)
e3 := fmt.Errorf("e3 -> %w", e2)
fmt.Println(Unwrap(e3))
//Output: e1
}
func TestUnwrap(t *testing.T) {
a := A{}
b := B{a}
c := C{b}
w := Unwrap[I](c)
if w != a {
t.Fatalf("w != rw, %+v", w)
}
}
type I interface {
F()
}
type A struct{}
func (A) F() {}
type B struct{ I }
func (b B) Unwrap() I { return b.I }
type C struct{ I }
func (c C) Unwrap() I { return c.I }