func testReadAt(t *testing.T, s *stream.Stream, off int64, want_err error, want string) { var ( err error msg string buf = []byte("......") str string ) msg = fmt.Sprintf("ReadAt([<%d>], %d),", len(buf), off) _, err = s.ReadAt(buf, off) if err != want_err { t.Errorf("%s want error `%v`, but got `%v`\n", msg, want_err, err) return } str = string(buf) if str != want { t.Errorf("%s got `%s`, want `%s`\n", msg, str, want) } }