def test_generate_code_returns_valid_sha1_string():
import re
code = Article.generate_code()
assert re.match(r'^[0-9a-f]{40}$', code)
def test_generate_code_returns_always_new_code():
codes = [c for c in filter(lambda x: Article.generate_code(), range(5))]
assert 5 == len(set(codes))
def test_generate_code_returns_fixed_length_string():
code = Article.generate_code()
assert 40 == len(code)