def test_compress_smaller_b(self):
'''
Function to test that an exception gets raised when a smaller b
needs to be chosen in order to compress the image
'''
with pytest.raises(Exception):
compress(big_img, 4, outpath)
def test_compress_already_compressed(self):
'''
Function to test that the function raises exceptions when
images that cannot be compressed further are passed in
'''
with pytest.raises(Exception):
compress(small_img, 8, outpath)
with pytest.raises(Exception):
compress(small_img, 1, outpath)
def test_compress_shape(self):
'''
Function to test that compressed image shape is the same
'''
com_path = compress(img_path, 3, outpath)
assert imread(com_path).shape == imread(img_path).shape
com_path = compress(img_path, 1, outpath)
assert imread(com_path).shape == imread(img_path).shape
com_path = compress(img_path, 6, outpath)
assert imread(com_path).shape == imread(img_path).shape
def test_compress_value(self):
'''
Function to test that a ValueError is raised
when invalid values are passed in for b
'''
with pytest.raises(ValueError):
compress(img_path, -1, outpath)
with pytest.raises(ValueError):
compress(img_path, 9, outpath)
with pytest.raises(ValueError):
compress(img_path, 0, outpath)
with pytest.raises(ValueError):
compress(img_path, 1000, outpath)
with pytest.raises(ValueError):
compress(img_path, -1000, outpath)
def test_compress_size(self):
'''
Function to test that the size of the compressed image
is correct
'''
compressed_img = compress(img_path, 3, outpath)
assert image_size(compressed_img) < 7 / 8 * image_size(img_path)
compressed_img = compress(img_path, 1, outpath)
assert image_size(compressed_img) < 5 / 8 * image_size(img_path)
compressed_img = compress(img_path, 6, outpath)
assert image_size(compressed_img) <= 8 / 8 * image_size(img_path)
compressed_img = compress(img_path, 8, outpath)
assert image_size(compressed_img) <= image_size(img_path)
def test_compress_type(self):
'''
Function to test that a TypeError is raised when an invalid type is
passed in for image or b
'''
with pytest.raises(TypeError):
compress(img_path, 6.5, outpath)
with pytest.raises(TypeError):
compress(imread(img_path), 2, outpath)
with pytest.raises(TypeError):
compress(5, True, outpath)
with pytest.raises(TypeError):
compress(img_path, 3, 5)