def test_write_png_produces_file_of_expected_size():
expected_size = 77 # Precomputed size of resulting PNG
white = [255, 255, 255]
black = [0, 0, 0]
pixel_rows = [black + white + black,
white + black + white,
black + white + black]
pixel_array = PixelArray(pixel_rows)
file = io.BytesIO()
write_pixels_to_png(pixel_array, file)
assert len(file.getvalue()) == expected_size
def execute(self):
with open(self._input_file, 'rb') as data_file:
with open(self._output_file, 'wb') as png_file:
data = read_data_from_file(data_file)
write_pixels_to_png(convert_bytes_to_pixels(data, self._width),
png_file)
def execute(self):
with open(self._input_file, 'rb') as data_file:
with open(self._output_file, 'wb') as png_file:
data = read_data_from_file(data_file)
write_pixels_to_png(convert_bytes_to_pixels(data, self._width),
png_file)