def test_always_reduces_integers_to_smallest_suitable_sizes(problem): n, blob = problem blob = hbytes(blob) try: d = ConjectureData.for_buffer(blob) k = d.draw(st.integers()) stop = blob[len(d.buffer)] except (StopTest, IndexError): reject() assume(k > n) assume(stop > 0) def f(data): k = data.draw(st.integers()) data.output = repr(k) if data.draw_bits(8) == stop and k >= n: data.mark_interesting() runner = ConjectureRunner( f, random=Random(0), settings=settings( suppress_health_check=HealthCheck.all(), phases=(Phase.shrink, ), database=None, verbosity=Verbosity.debug, ), database_key=None, ) runner.cached_test_function(blob) assert runner.interesting_examples v, = runner.interesting_examples.values() shrinker = runner.new_shrinker(v, lambda x: x.status == Status.INTERESTING) shrinker.fixate_shrink_passes(["minimize_individual_blocks"]) v = shrinker.shrink_target m = ConjectureData.for_buffer(v.buffer).draw(st.integers()) assert m == n # Upper bound on the length needed is calculated as follows: # * We have an initial byte at the beginning to decide the length of the # integer. # * We have a terminal byte as the stop value. # * The rest is the integer payload. This should be n. Including the sign # bit, n needs (1 + n.bit_length()) / 8 bytes (rounded up). But we only # have power of two sizes, so it may be up to a factor of two more than # that. bits_needed = 1 + n.bit_length() actual_bits_needed = min( [s for s in WideRangeIntStrategy.sizes if s >= bits_needed]) bytes_needed = actual_bits_needed // 8 # 3 extra bytes: two for the sampler, one for the capping value. assert len(v.buffer) == 3 + bytes_needed
def test_always_reduces_integers_to_smallest_suitable_sizes(problem): n, blob = problem blob = hbytes(blob) try: d = ConjectureData.for_buffer(blob) k = d.draw(st.integers()) stop = blob[len(d.buffer)] except (StopTest, IndexError): reject() assume(k > n) assume(stop > 0) def f(data): k = data.draw(st.integers()) data.output = repr(k) if data.draw_bits(8) == stop and k >= n: data.mark_interesting() runner = ConjectureRunner(f, random=Random(0), settings=settings( suppress_health_check=HealthCheck.all(), timeout=unlimited, phases=(Phase.shrink,), database=None, verbosity=Verbosity.debug ), database_key=None) runner.test_function(ConjectureData.for_buffer(blob)) assert runner.interesting_examples v, = runner.interesting_examples.values() shrinker = runner.new_shrinker(v, lambda x: x.status == Status.INTERESTING) shrinker.clear_passes() shrinker.add_new_pass('minimize_individual_blocks') shrinker.shrink() v = shrinker.shrink_target m = ConjectureData.for_buffer(v.buffer).draw(st.integers()) assert m == n # Upper bound on the length needed is calculated as follows: # * We have an initial byte at the beginning to decide the length of the # integer. # * We have a terminal byte as the stop value. # * The rest is the integer payload. This should be n. Including the sign # bit, n needs (1 + n.bit_length()) / 8 bytes (rounded up). But we only # have power of two sizes, so it may be up to a factor of two more than # that. bits_needed = 1 + n.bit_length() actual_bits_needed = min( [s for s in WideRangeIntStrategy.sizes if s >= bits_needed]) bytes_needed = actual_bits_needed // 8 # 3 extra bytes: two for the sampler, one for the capping value. assert len(v.buffer) == 3 + bytes_needed
def accept(f): with deterministic_PRNG(): runner = ConjectureRunner(f, settings=settings( max_examples=5000, buffer_size=1024, database=None, suppress_health_check=HealthCheck.all(), )) runner.test_function(ConjectureData.for_buffer(start)) assert runner.interesting_examples last_data, = runner.interesting_examples.values() return runner.new_shrinker( last_data, lambda d: d.status == Status.INTERESTING )
def test_only_calls_discard_at_top_level_pass(): def tree(data): data.start_example('tree') result = 1 if data.draw_bits(1): result += max(tree(data), tree(data)) data.stop_example() return result def f(data): if tree(data) == 3: data.mark_interesting() runner = ConjectureRunner(f, settings=settings( max_examples=1, buffer_size=1024, database=None, suppress_health_check=HealthCheck.all(), )) runner.test_function(ConjectureData.for_buffer([ 1, 0, 1, 0, 0, ])) assert runner.interesting_examples last_data, = runner.interesting_examples.values() shrinker = runner.new_shrinker(last_data, lambda d: d.status == Status.INTERESTING) shrinker.remove_discarded = MagicMock(return_value=None) shrinker.adaptive_example_deletion() assert shrinker.remove_discarded.call_count == 1