KaneAI - World’s First E2E Software Testing Agent.Book a Demo Join TestMu Conference

How to use is_valid_core method in hypothesis

Best Python code snippet using hypothesis

dfas.py

Source:dfas.py

...98    assert v == prefix + v_core + suffix, (list(u), list(v))99    better = runner.cached_test_function(u)100    worse = runner.cached_test_function(v)101    allow_discards = worse.has_discards or better.has_discards102    def is_valid_core(s):103        if not (len(u_core) <= len(s) <= len(v_core)):104            return False105        buf = prefix + s + suffix106        result = runner.cached_test_function(buf)107        return (108            predicate(result)109            # Because we're often using this to learn strategies110            # rather than entire complex test functions, it's111            # important that our replacements are precise and112            # don't leave the rest of the test case in a weird113            # state.114            and result.buffer == buf115            # Because the shrinker is good at removing discarded116            # data, unless we need discards to allow one or both117            # of u and v to result in valid shrinks, we don't118            # count attempts that have them as valid. This will119            # cause us to match fewer strings, which will make120            # the resulting shrink pass more efficient when run121            # on test functions it wasn't really intended for.122            and (allow_discards or not result.has_discards)123        )124    assert sort_key(u_core) < sort_key(v_core)125    assert is_valid_core(u_core)126    assert is_valid_core(v_core)127    learner = LStar(is_valid_core)128    prev = -1129    while learner.generation != prev:130        prev = learner.generation131        learner.learn(u_core)132        learner.learn(v_core)133        # L* has a tendency to learn DFAs which wrap around to134        # the beginning. We don't want to it to do that unless135        # it's accurate, so we use these as examples to show136        # check going around the DFA twice.137        learner.learn(u_core * 2)138        learner.learn(v_core * 2)139        if learner.dfa.max_length(learner.dfa.start) > len(v_core):140            # The language we learn is finite and bounded above141            # by the length of v_core. This is important in order142            # to keep our shrink passes reasonably efficient -143            # otherwise they can match far too much. So whenever144            # we learn a DFA that could match a string longer145            # than len(v_core) we fix it by finding the first146            # string longer than v_core and learning that as147            # a correction.148            x = next(learner.dfa.all_matching_strings(min_length=len(v_core) + 1))149            assert not is_valid_core(x)150            learner.learn(x)151            assert not learner.dfa.matches(x)152            assert learner.generation != prev153        else:154            # We mostly care about getting the right answer on the155            # minimal test case, but because we're doing this offline156            # anyway we might as well spend a little more time trying157            # small examples to make sure the learner gets them right.158            for x in islice(learner.dfa.all_matching_strings(), 100):159                if not is_valid_core(x):160                    learner.learn(x)161                    assert learner.generation != prev162                    break163    # We've now successfully learned a DFA that works for shrinking164    # our failed normalisation further. Canonicalise it into a concrete165    # DFA so we can save it for later.166    new_dfa = learner.dfa.canonicalise()167    assert math.isfinite(new_dfa.max_length(new_dfa.start))168    shrinker = runner.new_shrinker(runner.cached_test_function(v), predicate)169    assert (len(prefix), len(v) - len(suffix)) in shrinker.matching_regions(new_dfa)170    name = "tmp-dfa-" + repr(new_dfa)171    shrinker.extra_dfas[name] = new_dfa172    shrinker.fixate_shrink_passes([dfa_replacement(name)])173    assert sort_key(shrinker.buffer) < sort_key(v)...

Automation Testing Tutorials

Learn to execute automation testing from scratch with LambdaTest Learning Hub. Right from setting up the prerequisites to run your first automation test, to following best practices and diving deeper into advanced test scenarios. LambdaTest Learning Hubs compile a list of step-by-step guides to help you be proficient with different test automation frameworks i.e. Selenium, Cypress, TestNG etc.