def test_scheme_serialization_basic():
preload, test_input = map(_stable_json_dump, [
{'a': 123, 'b': 44, 'c': 92},
{'a': 42, 'b': 44, 'c': 91},
])
scheme = ZlibPlcdScheme('x_v1', preload)
scheme_reconstructed = ZlibPlcdScheme.from_json_description_dict(
scheme.json_description_dict()
)
assert len(scheme.compress(test_input)) == 20
assert scheme_reconstructed.compress(test_input) == scheme.compress(test_input)
def test_compression_is_better_basic():
"""Checks that PLCD is better than nothing or vanilla
zlib for a basic input case.
"""
preload, test_input = map(_stable_json_dump, [
{'a': 123, 'b': 44, 'c': 92},
{'a': 42, 'b': 44, 'c': 91},
])
scheme = ZlibPlcdScheme('x_v1', preload)
assert len(test_input) == 27
assert len(zlib.compress(test_input)) == 30
assert len(scheme.compress(test_input)) == 20
def test_raises_if_bad_tag():
"""Check that assertions are raised if compressed data isn't tagged."""
scheme = ZlibPlcdScheme('x_v1', '')
with pytest.raises(ValueError):
scheme.decompress('')
def test_compress_and_decompress():
"""Test that decompress(compress(x)) == x."""
scheme = ZlibPlcdScheme('hi', 'fandangle')
for input_str in ('catfood', 'fandangle2'):
compressed = scheme.compress(input_str)
assert scheme.decompress(compressed) == input_str
