if b.off > 0 {
		b.off--
	}
	return nil
}

// ReadBytes reads until the first occurrence of delim in the input,
// returning a slice containing the data up to and including the delimiter.
// If ReadBytes encounters an error before finding a delimiter,
// it returns the data read before the error and the error itself (often [io.EOF]).
// ReadBytes returns err != nil if and only if the returned data does not end in
// delim.

}

func TestReaderSimple(t *testing.T) {
	data := "hello world"
	b := NewReader(strings.NewReader(data))
	if s := readBytes(b); s != "hello world" {
		t.Errorf("simple hello world test failed: got %q", s)
	}

	b = NewReader(newRot13Reader(strings.NewReader(data)))
	if s := readBytes(b); s != "uryyb jbeyq" {
		t.Errorf("rot13 hello world test failed: got %q", s)
	}
}

type readMaker struct {
	name string