buf, err := io.ReadAll(r)
	if err != nil {
		t.Errorf("ReadAll: unexpected error: %v", err)
	}
	if got := string(buf); got != want {
		t.Errorf("ReadAll: got %q, want %q", got, want)
	}
}

func TestReaderZero(t *testing.T) {
	if l := (&Reader{}).Len(); l != 0 {
		t.Errorf("Len: got %d, want 0", l)
	}

	if n, err := (&Reader{}).Read(nil); n != 0 || err != io.EOF {
		t.Errorf("Read: got %d, %v; want 0, io.EOF", n, err)