t.Errorf("Unexpected error while writing with flush writer: %v", err)
		}
	}
	if w.writeCount != 10 {
		t.Errorf("Write not called the expected number of times. Actual: %d", w.writeCount)
	}
}

func TestWriteError(t *testing.T) {
	e := fmt.Errorf("Error")
	w := &writerWithFlush{err: e}
	fw := Wrap(w)
	_, err := fw.Write([]byte("Test write"))
	if err != e {
		t.Errorf("Did not get expected error. Got: %#v", err)
	}

func (e *errorWriter) Write(b []byte) (int, error) {
	if e.N <= 0 {
		return 0, io.ErrClosedPipe
	}
	e.N--
	return len(b), nil
}

// Test if errors from the underlying writer is passed upwards.
func TestWriteError(t *testing.T) {
	t.Parallel()
	buf := new(bytes.Buffer)
	n := 65536
	if !testing.Short() {
		n *= 4
	}
	for i := 0; i < n; i++ {
		fmt.Fprintf(buf, "asdasfasf%d%dfghfgujyut%dyutyu\n", i, i, i)
	}