package sessionresolver import ( "errors" "io" "testing" "github.com/google/go-cmp/cmp" ) func TestErrWrapper(t *testing.T) { ew := newErrWrapper(io.EOF, "https://dns.quad9.net/dns-query") o := ew.Error() expect := " EOF" if diff := cmp.Diff(expect, o); diff != "" { t.Fatal(diff) } if !errors.Is(ew, io.EOF) { t.Fatal("not the sub-error we expected") } if errors.Unwrap(ew) != io.EOF { t.Fatal("unwrap failed") } }