def test_return_line_contract_violation(self):
"""BufferWorkSpace (of a completely empty file) would result in contract violation for return_line."""
with patch("file_read_backwards.buffer_work_space._get_file_size"
) as _get_file_size_mock:
fp_mock = Mock()
_get_file_size_mock.return_value = 0
b = BufferWorkSpace(fp_mock, chunk_size=io.DEFAULT_BUFFER_SIZE)
with self.assertRaises(AssertionError):
b.return_line()
def test_return_line_with_buffer_space_with_two_new_lines(self):
"""With two new lines as its sole contents, the buffer space is expected to return b''."""
with patch("file_read_backwards.buffer_work_space._get_file_size"
) as _get_file_size_mock:
fp_mock = Mock()
_get_file_size_mock.return_value = 1024
for n in new_lines_bytes:
b = BufferWorkSpace(fp_mock, chunk_size=io.DEFAULT_BUFFER_SIZE)
b.read_position = 1024 - (len(n) * 2)
b.read_buffer = n * 2
expected_result = b""
r = b.return_line()
self.assertEqual(r, expected_result)
def test_return_line_with_buffer_space_with_fully_read_in_contents_at_its_last_line(
self):
"""With some bytestrings in between 2 new lines, expect to have the bytestrings in the middle."""
with patch("file_read_backwards.buffer_work_space._get_file_size"
) as _get_file_size_mock:
fp_mock = Mock()
_get_file_size_mock.return_value = 1024
for n in new_lines_bytes:
b = BufferWorkSpace(fp_mock, chunk_size=io.DEFAULT_BUFFER_SIZE)
b.read_position = 0
b.read_buffer = b"LastLineYay"
expected_result = b"LastLineYay"
r = b.return_line()
self.assertEqual(r, expected_result)
def test_return_line_with_buffer_space_with_some_contents_between_two_new_lines(
self):
"""With some bytestrings in between 2 new lines, expect to have the bytestrings in the middle."""
with patch("file_read_backwards.buffer_work_space._get_file_size"
) as _get_file_size_mock:
fp_mock = Mock()
_get_file_size_mock.return_value = 1024
for n in new_lines_bytes:
b = BufferWorkSpace(fp_mock, chunk_size=io.DEFAULT_BUFFER_SIZE)
b.read_position = 1024 - (len(n) * 2)
b.read_buffer = n + b"Something" + n
expected_result = b"Something"
r = b.return_line()
self.assertEqual(r, expected_result)
