r.buf = r.buf[read:]

	switch read {
	case 0, len(r.buf):
		// As allowed in the documentation, this will return io.EOF
		// in the same call that consumes the last of the data.
		// https://godoc.org/io#Reader
		return read, io.EOF
	}

	return read, nil
}

func TestPartialReadEOF(t *testing.T) {
	src := make([]byte, 10)
	eofR := &eofReader{buf: src}
	r := NewReader(eofR)