def test_read_next_chunk_eof(self):
with io.BytesIO() as stream:
# If:
# ... I create a reader with a stream that has no bytes
reader = JSONRPCReader(stream, logger=utils.get_mock_logger())
# ... and I read a chunk from the stream
# Then: I should get an exception
with self.assertRaises(EOFError):
reader._read_next_chunk()
def test_read_next_chunk_closed(self):
# Setup: Create a stream that has already been closed
stream = io.BytesIO()
stream.close()
# If:
# ... I create a reader with a closed stream
reader = JSONRPCReader(stream, logger=utils.get_mock_logger())
# ... and I read a chunk from the stream
# Then: I should get an exception
with self.assertRaises(ValueError):
reader._read_next_chunk()
def test_read_next_chunk_resize(self):
# Setup: Create a byte array for test input
test_bytes = bytearray(b'1234567890')
with io.BytesIO(test_bytes) as stream:
# If:
# ... I create a reader with an artificially low initial buffer size
# and prefill the buffer
reader = JSONRPCReader(stream, logger=utils.get_mock_logger())
reader._buffer = bytearray(5)
reader._buffer_end_offset = 4
# ... and I read a chunk from the stream
result = reader._read_next_chunk()
# Then:
# ... The read should have succeeded
self.assertTrue(result, True)
# ... The size of the buffer should have doubled
self.assertEqual(len(reader._buffer), 10)
# ... The buffer end offset should be the size of the buffer
self.assertEqual(reader._buffer_end_offset, 10)
# ... The buffer should contain the first 6 elements of the test data
expected = test_bytes[:6]
actual = reader._buffer[4:]
self.assertEqual(actual, expected)
def test_read_next_chunk_success(self):
# Setup: Create a byte array for test input
test_bytes = bytearray(b'123')
with io.BytesIO(test_bytes) as stream:
# If: I attempt to read a chunk from the stream
reader = JSONRPCReader(stream, logger=utils.get_mock_logger())
result = reader._read_next_chunk()
# Then:
# ... The result should be true
self.assertTrue(result)
# ... The buffer should contain 3 byte and should not have been read yet
self.assertEqual(reader._buffer_end_offset, len(test_bytes))
self.assertEqual(reader._read_offset, 0)
# ... The buffer should now contain the bytes from the stream
buffer_contents = reader._buffer[:len(test_bytes)]
self.assertEqual(buffer_contents, test_bytes)