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How to use optimise_targets method in hypothesis

Best Python code snippet using hypothesis

test_engine.py

Source:test_engine.py

1# This file is part of Hypothesis, which may be found at2# https://github.com/HypothesisWorks/hypothesis/3#4# Most of this work is copyright (C) 2013-2020 David R. MacIver5# (david@drmaciver.com), but it contains contributions by others. See6# CONTRIBUTING.rst for a full list of people who may hold copyright, and7# consult the git log if you need to determine who owns an individual8# contribution.9#10# This Source Code Form is subject to the terms of the Mozilla Public License,11# v. 2.0. If a copy of the MPL was not distributed with this file, You can12# obtain one at https://mozilla.org/MPL/2.0/.13#14# END HEADER15import re16import time17from random import Random18from unittest.mock import Mock19import pytest20from hypothesis import HealthCheck, Phase, Verbosity, settings21from hypothesis.database import ExampleDatabase, InMemoryExampleDatabase22from hypothesis.errors import FailedHealthCheck, Flaky23from hypothesis.internal.compat import int_from_bytes24from hypothesis.internal.conjecture import engine as engine_module25from hypothesis.internal.conjecture.data import ConjectureData, Overrun, Status26from hypothesis.internal.conjecture.engine import (27    MIN_TEST_CALLS,28    ConjectureRunner,29    ExitReason,30    RunIsComplete,31)32from hypothesis.internal.conjecture.pareto import DominanceRelation, dominance33from hypothesis.internal.conjecture.shrinker import Shrinker, block_program34from hypothesis.internal.conjecture.utils import integer_range35from hypothesis.internal.entropy import deterministic_PRNG36from tests.common.strategies import SLOW, HardToShrink37from tests.common.utils import no_shrink38from tests.conjecture.common import (39    SOME_LABEL,40    TEST_SETTINGS,41    buffer_size_limit,42    run_to_buffer,43    run_to_data,44    shrinking_from,45)46def test_can_index_results():47    @run_to_buffer48    def f(data):49        data.draw_bytes(5)50        data.mark_interesting()51    assert f.index(0) == 052    assert f.count(0) == 553def test_non_cloneable_intervals():54    @run_to_buffer55    def x(data):56        data.draw_bytes(10)57        data.draw_bytes(9)58        data.mark_interesting()59    assert x == bytes(19)60def test_deletable_draws():61    @run_to_buffer62    def x(data):63        while True:64            x = data.draw_bytes(2)65            if x[0] == 255:66                data.mark_interesting()67    assert x == bytes([255, 0])68def zero_dist(random, n):69    return bytes(n)70def test_can_load_data_from_a_corpus():71    key = b"hi there"72    db = ExampleDatabase()73    value = b"=\xc3\xe4l\x81\xe1\xc2H\xc9\xfb\x1a\xb6bM\xa8\x7f"74    db.save(key, value)75    def f(data):76        if data.draw_bytes(len(value)) == value:77            data.mark_interesting()78    runner = ConjectureRunner(f, settings=settings(database=db), database_key=key)79    runner.run()80    (last_data,) = runner.interesting_examples.values()81    assert last_data.buffer == value82    assert len(list(db.fetch(key))) == 183def slow_shrinker():84    strat = HardToShrink()85    def accept(data):86        if data.draw(strat):87            data.mark_interesting()88    return accept89@pytest.mark.parametrize("n", [1, 5])90def test_terminates_shrinks(n, monkeypatch):91    from hypothesis.internal.conjecture import engine92    db = InMemoryExampleDatabase()93    def generate_new_examples(self):94        self.cached_test_function([255] * 1000)95    monkeypatch.setattr(96        ConjectureRunner, "generate_new_examples", generate_new_examples97    )98    monkeypatch.setattr(engine, "MAX_SHRINKS", n)99    runner = ConjectureRunner(100        slow_shrinker(),101        settings=settings(max_examples=5000, database=db),102        random=Random(0),103        database_key=b"key",104    )105    runner.run()106    (last_data,) = runner.interesting_examples.values()107    assert last_data.status == Status.INTERESTING108    assert runner.shrinks == n109    in_db = set(db.data[runner.secondary_key])110    assert len(in_db) == n111def test_detects_flakiness():112    failed_once = [False]113    count = [0]114    def tf(data):115        data.draw_bytes(1)116        count[0] += 1117        if not failed_once[0]:118            failed_once[0] = True119            data.mark_interesting()120    runner = ConjectureRunner(tf)121    runner.run()122    assert runner.exit_reason == ExitReason.flaky123    assert count == [MIN_TEST_CALLS + 1]124def recur(i, data):125    try:126        if i >= 1:127            recur(i - 1, data)128    except RecursionError:129        data.mark_interesting()130def test_recursion_error_is_not_flaky():131    def tf(data):132        i = data.draw_bits(16)133        recur(i, data)134    runner = ConjectureRunner(tf)135    runner.run()136    assert runner.exit_reason == ExitReason.finished137def test_variadic_draw():138    def draw_list(data):139        result = []140        while True:141            data.start_example(SOME_LABEL)142            d = data.draw_bytes(1)[0] & 7143            if d:144                result.append(data.draw_bytes(d))145            data.stop_example()146            if not d:147                break148        return result149    @run_to_buffer150    def b(data):151        if any(all(d) for d in draw_list(data)):152            data.mark_interesting()153    ls = draw_list(ConjectureData.for_buffer(b))154    assert len(ls) == 1155    assert len(ls[0]) == 1156def test_draw_to_overrun():157    @run_to_buffer158    def x(data):159        d = (data.draw_bytes(1)[0] - 8) & 0xFF160        data.draw_bytes(128 * d)161        if d >= 2:162            data.mark_interesting()163    assert x == bytes([10]) + bytes(128 * 2)164def test_can_navigate_to_a_valid_example():165    def f(data):166        i = int_from_bytes(data.draw_bytes(2))167        data.draw_bytes(i)168        data.mark_interesting()169    runner = ConjectureRunner(f, settings=settings(max_examples=5000, database=None))170    with buffer_size_limit(2):171        runner.run()172    assert runner.interesting_examples173def test_stops_after_max_examples_when_reading():174    key = b"key"175    db = ExampleDatabase(":memory:")176    for i in range(10):177        db.save(key, bytes([i]))178    seen = []179    def f(data):180        seen.append(data.draw_bytes(1))181    runner = ConjectureRunner(182        f, settings=settings(max_examples=1, database=db), database_key=key183    )184    runner.run()185    assert len(seen) == 1186def test_stops_after_max_examples_when_generating():187    seen = []188    def f(data):189        seen.append(data.draw_bytes(1))190    runner = ConjectureRunner(f, settings=settings(max_examples=1, database=None))191    runner.run()192    assert len(seen) == 1193@pytest.mark.parametrize("examples", [1, 5, 20, 50])194def test_stops_after_max_examples_when_generating_more_bugs(examples):195    seen = []196    bad = [False, False]197    def f(data):198        seen.append(data.draw_bits(32))199        # Rare, potentially multi-error conditions200        if seen[-1] > 2 ** 31:201            bad[0] = True202            raise ValueError203        bad[1] = True204        raise Exception205    runner = ConjectureRunner(206        f, settings=settings(max_examples=examples, phases=[Phase.generate])207    )208    try:209        runner.run()210    except Exception:211        pass212    # No matter what, whether examples is larger or smalller than MAX_TEST_CALLS,213    # we stop looking at max_examples.  (and re-run each failure for the traceback)214    assert len(seen) <= examples + sum(bad)215def test_interleaving_engines():216    children = []217    @run_to_buffer218    def x(data):219        rnd = Random(data.draw_bytes(1))220        def g(d2):221            d2.draw_bytes(1)222            data.mark_interesting()223        runner = ConjectureRunner(g, random=rnd)224        children.append(runner)225        runner.run()226        if runner.interesting_examples:227            data.mark_interesting()228    assert x == b"\0"229    for c in children:230        assert not c.interesting_examples231def test_phases_can_disable_shrinking():232    seen = set()233    def f(data):234        seen.add(bytes(data.draw_bytes(32)))235        data.mark_interesting()236    runner = ConjectureRunner(237        f, settings=settings(database=None, phases=(Phase.reuse, Phase.generate))238    )239    runner.run()240    assert len(seen) == MIN_TEST_CALLS241def test_reuse_phase_runs_for_max_examples_if_generation_is_disabled():242    with deterministic_PRNG():243        db = InMemoryExampleDatabase()244        for i in range(256):245            db.save(b"key", bytes([i]))246        seen = set()247        def test(data):248            seen.add(data.draw_bits(8))249        ConjectureRunner(250            test,251            settings=settings(max_examples=100, database=db, phases=[Phase.reuse]),252            database_key=b"key",253        ).run()254        assert len(seen) == 100255def test_erratic_draws():256    n = [0]257    with pytest.raises(Flaky):258        @run_to_buffer259        def x(data):260            data.draw_bytes(n[0])261            data.draw_bytes(255 - n[0])262            if n[0] == 255:263                data.mark_interesting()264            else:265                n[0] += 1266def test_no_read_no_shrink():267    count = [0]268    @run_to_buffer269    def x(data):270        count[0] += 1271        data.mark_interesting()272    assert x == b""273    assert count == [1]274def test_one_dead_branch():275    with deterministic_PRNG():276        seen = set()277        @run_to_buffer278        def x(data):279            i = data.draw_bytes(1)[0]280            if i > 0:281                data.mark_invalid()282            i = data.draw_bytes(1)[0]283            if len(seen) < 255:284                seen.add(i)285            elif i not in seen:286                data.mark_interesting()287def test_does_not_save_on_interrupt():288    def interrupts(data):289        raise KeyboardInterrupt()290    db = InMemoryExampleDatabase()291    runner = ConjectureRunner(292        interrupts, settings=settings(database=db), database_key=b"key"293    )294    with pytest.raises(KeyboardInterrupt):295        runner.run()296    assert not db.data297def test_returns_written():298    value = b"\0\1\2\3"299    @run_to_buffer300    def written(data):301        data.write(value)302        data.mark_interesting()303    assert value == written304def fails_health_check(label, **kwargs):305    def accept(f):306        runner = ConjectureRunner(307            f,308            settings=settings(309                max_examples=100, phases=no_shrink, database=None, **kwargs310            ),311        )312        with pytest.raises(FailedHealthCheck) as e:313            runner.run()314        assert e.value.health_check == label315        assert not runner.interesting_examples316    return accept317def test_fails_health_check_for_all_invalid():318    @fails_health_check(HealthCheck.filter_too_much)319    def _(data):320        data.draw_bytes(2)321        data.mark_invalid()322def test_fails_health_check_for_large_base():323    @fails_health_check(HealthCheck.large_base_example)324    def _(data):325        data.draw_bytes(10 ** 6)326def test_fails_health_check_for_large_non_base():327    @fails_health_check(HealthCheck.data_too_large)328    def _(data):329        if data.draw_bits(8):330            data.draw_bytes(10 ** 6)331def test_fails_health_check_for_slow_draws():332    @fails_health_check(HealthCheck.too_slow)333    def _(data):334        data.draw(SLOW)335@pytest.mark.parametrize("n_large", [1, 5, 8, 15])336def test_can_shrink_variable_draws(n_large):337    target = 128 * n_large338    @run_to_data339    def data(data):340        n = data.draw_bits(4)341        b = [data.draw_bits(8) for _ in range(n)]342        if sum(b) >= target:343            data.mark_interesting()344    x = data.buffer345    assert x.count(0) == 0346    assert sum(x[1:]) == target347def test_run_nothing():348    def f(data):349        assert False350    runner = ConjectureRunner(f, settings=settings(phases=()))351    runner.run()352    assert runner.call_count == 0353class Foo:354    def __repr__(self):355        return "stuff"356def test_debug_data(capsys):357    buf = [0, 1, 2]358    def f(data):359        for x in bytes(buf):360            if data.draw_bits(8) != x:361                data.mark_invalid()362            data.start_example(1)363            data.stop_example()364        data.mark_interesting()365    runner = ConjectureRunner(366        f,367        settings=settings(368            max_examples=5000,369            database=None,370            suppress_health_check=HealthCheck.all(),371            verbosity=Verbosity.debug,372        ),373    )374    runner.cached_test_function(buf)375    runner.run()376    out, _ = capsys.readouterr()377    assert re.match("\\d+ bytes \\[.*\\] -> ", out)378    assert "INTERESTING" in out379def test_can_write_bytes_towards_the_end():380    buf = b"\1\2\3"381    def f(data):382        if data.draw_bits(1):383            data.draw_bytes(5)384            data.write(bytes(buf))385            assert bytes(data.buffer[-len(buf) :]) == buf386    with buffer_size_limit(10):387        ConjectureRunner(f).run()388def test_uniqueness_is_preserved_when_writing_at_beginning():389    seen = set()390    def f(data):391        data.write(bytes(1))392        n = data.draw_bits(3)393        assert n not in seen394        seen.add(n)395    runner = ConjectureRunner(f, settings=settings(max_examples=50))396    runner.run()397    assert runner.valid_examples == len(seen)398@pytest.mark.parametrize("skip_target", [False, True])399@pytest.mark.parametrize("initial_attempt", [127, 128])400def test_clears_out_its_database_on_shrinking(401    initial_attempt, skip_target, monkeypatch402):403    def generate_new_examples(self):404        self.cached_test_function(initial_attempt)405    monkeypatch.setattr(406        ConjectureRunner, "generate_new_examples", generate_new_examples407    )408    key = b"key"409    db = InMemoryExampleDatabase()410    def f(data):411        if data.draw_bits(8) >= 127:412            data.mark_interesting()413    runner = ConjectureRunner(414        f,415        settings=settings(database=db, max_examples=256),416        database_key=key,417        random=Random(0),418    )419    for n in range(256):420        if n != 127 or not skip_target:421            db.save(runner.secondary_key, bytes([n]))422    runner.run()423    assert len(runner.interesting_examples) == 1424    for b in db.fetch(runner.secondary_key):425        assert b[0] >= 127426    assert len(list(db.fetch(runner.database_key))) == 1427def test_detects_too_small_block_starts():428    call_count = [0]429    def f(data):430        assert call_count[0] == 0431        call_count[0] += 1432        data.draw_bytes(8)433        data.mark_interesting()434    runner = ConjectureRunner(f, settings=settings(database=None))435    r = runner.cached_test_function(bytes(8))436    assert r.status == Status.INTERESTING437    assert call_count[0] == 1438    r2 = runner.cached_test_function(bytes([255] * 7))439    assert r2.status == Status.OVERRUN440    assert call_count[0] == 1441def test_shrinks_both_interesting_examples(monkeypatch):442    def generate_new_examples(self):443        self.cached_test_function(bytes([1]))444    monkeypatch.setattr(445        ConjectureRunner, "generate_new_examples", generate_new_examples446    )447    def f(data):448        n = data.draw_bits(8)449        data.mark_interesting(n & 1)450    runner = ConjectureRunner(f, database_key=b"key")451    runner.run()452    assert runner.interesting_examples[0].buffer == bytes([0])453    assert runner.interesting_examples[1].buffer == bytes([1])454def test_discarding(monkeypatch):455    monkeypatch.setattr(Shrinker, "shrink", Shrinker.remove_discarded)456    monkeypatch.setattr(457        ConjectureRunner,458        "generate_new_examples",459        lambda runner: runner.cached_test_function(bytes([0, 1] * 10)),460    )461    @run_to_buffer462    def x(data):463        count = 0464        while count < 10:465            data.start_example(SOME_LABEL)466            b = data.draw_bits(1)467            if b:468                count += 1469            data.stop_example(discard=not b)470        data.mark_interesting()471    assert x == bytes(bytes([1]) * 10)472def test_can_remove_discarded_data():473    @shrinking_from(bytes([0] * 10 + [11]))474    def shrinker(data):475        while True:476            data.start_example(SOME_LABEL)477            b = data.draw_bits(8)478            data.stop_example(discard=(b == 0))479            if b == 11:480                break481        data.mark_interesting()482    shrinker.remove_discarded()483    assert list(shrinker.buffer) == [11]484def test_discarding_iterates_to_fixed_point():485    @shrinking_from(bytes(list(range(100, -1, -1))))486    def shrinker(data):487        data.start_example(0)488        data.draw_bits(8)489        data.stop_example(discard=True)490        while data.draw_bits(8):491            pass492        data.mark_interesting()493    shrinker.remove_discarded()494    assert list(shrinker.buffer) == [1, 0]495def test_discarding_is_not_fooled_by_empty_discards():496    @shrinking_from(bytes([1, 1]))497    def shrinker(data):498        data.draw_bits(1)499        data.start_example(0)500        data.stop_example(discard=True)501        data.draw_bits(1)502        data.mark_interesting()503    shrinker.remove_discarded()504    assert shrinker.shrink_target.has_discards505def test_discarding_can_fail(monkeypatch):506    @shrinking_from(bytes([1]))507    def shrinker(data):508        data.start_example(0)509        data.draw_bits(1)510        data.stop_example(discard=True)511        data.mark_interesting()512    shrinker.remove_discarded()513    assert any(e.discarded and e.length > 0 for e in shrinker.shrink_target.examples)514def test_shrinking_from_mostly_zero(monkeypatch):515    monkeypatch.setattr(516        ConjectureRunner,517        "generate_new_examples",518        lambda self: self.cached_test_function(bytes(5) + bytes([2])),519    )520    @run_to_buffer521    def x(data):522        s = [data.draw_bits(8) for _ in range(6)]523        if any(s):524            data.mark_interesting()525    assert x == bytes(5) + bytes([1])526def test_handles_nesting_of_discard_correctly(monkeypatch):527    monkeypatch.setattr(Shrinker, "shrink", Shrinker.remove_discarded)528    monkeypatch.setattr(529        ConjectureRunner,530        "generate_new_examples",531        lambda runner: runner.cached_test_function(bytes([0, 0, 1, 1])),532    )533    @run_to_buffer534    def x(data):535        while True:536            data.start_example(SOME_LABEL)537            succeeded = data.draw_bits(1)538            data.start_example(SOME_LABEL)539            data.draw_bits(1)540            data.stop_example(discard=not succeeded)541            data.stop_example(discard=not succeeded)542            if succeeded:543                data.mark_interesting()544    assert x == bytes([1, 1])545def test_database_clears_secondary_key():546    key = b"key"547    database = InMemoryExampleDatabase()548    def f(data):549        if data.draw_bits(8) == 10:550            data.mark_interesting()551        else:552            data.mark_invalid()553    runner = ConjectureRunner(554        f,555        settings=settings(556            max_examples=1, database=database, suppress_health_check=HealthCheck.all()557        ),558        database_key=key,559    )560    for i in range(10):561        database.save(runner.secondary_key, bytes([i]))562    runner.cached_test_function([10])563    assert runner.interesting_examples564    assert len(set(database.fetch(key))) == 1565    assert len(set(database.fetch(runner.secondary_key))) == 10566    runner.clear_secondary_key()567    assert len(set(database.fetch(key))) == 1568    assert len(set(database.fetch(runner.secondary_key))) == 0569def test_database_uses_values_from_secondary_key():570    key = b"key"571    database = InMemoryExampleDatabase()572    def f(data):573        if data.draw_bits(8) >= 5:574            data.mark_interesting()575        else:576            data.mark_invalid()577    runner = ConjectureRunner(578        f,579        settings=settings(580            max_examples=1, database=database, suppress_health_check=HealthCheck.all()581        ),582        database_key=key,583    )584    for i in range(10):585        database.save(runner.secondary_key, bytes([i]))586    runner.cached_test_function([10])587    assert runner.interesting_examples588    assert len(set(database.fetch(key))) == 1589    assert len(set(database.fetch(runner.secondary_key))) == 10590    runner.clear_secondary_key()591    assert len(set(database.fetch(key))) == 1592    assert set(map(int_from_bytes, database.fetch(runner.secondary_key))) == set(593        range(6, 11)594    )595    (v,) = runner.interesting_examples.values()596    assert list(v.buffer) == [5]597def test_exit_because_max_iterations():598    def f(data):599        data.draw_bits(64)600        data.mark_invalid()601    runner = ConjectureRunner(602        f,603        settings=settings(604            max_examples=1, database=None, suppress_health_check=HealthCheck.all()605        ),606    )607    runner.run()608    assert runner.call_count <= 1000609    assert runner.exit_reason == ExitReason.max_iterations610def test_exit_because_shrink_phase_timeout(monkeypatch):611    val = [0]612    def fast_time():613        val[0] += 1000614        return val[0]615    def f(data):616        if data.draw_bits(64) > 2 ** 33:617            data.mark_interesting()618    monkeypatch.setattr(time, "perf_counter", fast_time)619    runner = ConjectureRunner(f, settings=settings(database=None))620    runner.run()621    assert runner.exit_reason == ExitReason.very_slow_shrinking622    assert runner.statistics["stopped-because"] == "shrinking was very slow"623def test_dependent_block_pairs_can_lower_to_zero():624    @shrinking_from([1, 0, 1])625    def shrinker(data):626        if data.draw_bits(1):627            n = data.draw_bits(16)628        else:629            n = data.draw_bits(8)630        if n == 1:631            data.mark_interesting()632    shrinker.fixate_shrink_passes(["minimize_individual_blocks"])633    assert list(shrinker.shrink_target.buffer) == [0, 1]634def test_handle_size_too_large_during_dependent_lowering():635    @shrinking_from([1, 255, 0])636    def shrinker(data):637        if data.draw_bits(1):638            data.draw_bits(16)639            data.mark_interesting()640        else:641            data.draw_bits(8)642    shrinker.fixate_shrink_passes(["minimize_individual_blocks"])643def test_block_may_grow_during_lexical_shrinking():644    initial = bytes([2, 1, 1])645    @shrinking_from(initial)646    def shrinker(data):647        n = data.draw_bits(8)648        if n == 2:649            data.draw_bits(8)650            data.draw_bits(8)651        else:652            data.draw_bits(16)653        data.mark_interesting()654    shrinker.fixate_shrink_passes(["minimize_individual_blocks"])655    assert list(shrinker.shrink_target.buffer) == [0, 0, 0]656def test_lower_common_block_offset_does_nothing_when_changed_blocks_are_zero():657    @shrinking_from([1, 0, 1, 0])658    def shrinker(data):659        data.draw_bits(1)660        data.draw_bits(1)661        data.draw_bits(1)662        data.draw_bits(1)663        data.mark_interesting()664    shrinker.mark_changed(1)665    shrinker.mark_changed(3)666    shrinker.lower_common_block_offset()667    assert list(shrinker.shrink_target.buffer) == [1, 0, 1, 0]668def test_lower_common_block_offset_ignores_zeros():669    @shrinking_from([2, 2, 0])670    def shrinker(data):671        n = data.draw_bits(8)672        data.draw_bits(8)673        data.draw_bits(8)674        if n > 0:675            data.mark_interesting()676    for i in range(3):677        shrinker.mark_changed(i)678    shrinker.lower_common_block_offset()679    assert list(shrinker.shrink_target.buffer) == [1, 1, 0]680def test_pandas_hack():681    @shrinking_from([2, 1, 1, 7])682    def shrinker(data):683        n = data.draw_bits(8)684        m = data.draw_bits(8)685        if n == 1:686            if m == 7:687                data.mark_interesting()688        data.draw_bits(8)689        if data.draw_bits(8) == 7:690            data.mark_interesting()691    shrinker.fixate_shrink_passes([block_program("-XX")])692    assert list(shrinker.shrink_target.buffer) == [1, 7]693def test_cached_test_function_returns_right_value():694    count = [0]695    def tf(data):696        count[0] += 1697        data.draw_bits(2)698        data.mark_interesting()699    with deterministic_PRNG():700        runner = ConjectureRunner(tf, settings=TEST_SETTINGS)701        for _ in range(2):702            for b in (b"\0", b"\1"):703                d = runner.cached_test_function(b)704                assert d.status == Status.INTERESTING705                assert d.buffer == b706        assert count[0] == 2707def test_cached_test_function_does_not_reinvoke_on_prefix():708    call_count = [0]709    def test_function(data):710        call_count[0] += 1711        data.draw_bits(8)712        data.write(bytes([7]))713        data.draw_bits(8)714    with deterministic_PRNG():715        runner = ConjectureRunner(test_function, settings=TEST_SETTINGS)716        data = runner.cached_test_function(bytes(3))717        assert data.status == Status.VALID718        for n in [2, 1, 0]:719            prefix_data = runner.cached_test_function(bytes(n))720            assert prefix_data is Overrun721        assert call_count[0] == 1722def test_will_evict_entries_from_the_cache(monkeypatch):723    monkeypatch.setattr(engine_module, "CACHE_SIZE", 5)724    count = [0]725    def tf(data):726        data.draw_bytes(1)727        count[0] += 1728    runner = ConjectureRunner(tf, settings=TEST_SETTINGS)729    for _ in range(3):730        for n in range(10):731            runner.cached_test_function([n])732    # Because we exceeded the cache size, our previous733    # calls will have been evicted, so each call to734    # cached_test_function will have to reexecute.735    assert count[0] == 30736def test_branch_ending_in_write():737    seen = set()738    def tf(data):739        count = 0740        while data.draw_bits(1):741            count += 1742        if count > 1:743            data.draw_bits(1, forced=0)744        b = bytes(data.buffer)745        assert b not in seen746        seen.add(b)747    with deterministic_PRNG():748        runner = ConjectureRunner(tf, settings=TEST_SETTINGS)749        for _ in range(100):750            prefix = runner.generate_novel_prefix()751            attempt = prefix + bytes(2)752            data = runner.cached_test_function(attempt)753            assert data.status == Status.VALID754            assert attempt.startswith(data.buffer)755def test_exhaust_space():756    with deterministic_PRNG():757        runner = ConjectureRunner(758            lambda data: data.draw_bits(1), settings=TEST_SETTINGS759        )760        runner.run()761        assert runner.tree.is_exhausted762        assert runner.valid_examples == 2763SMALL_COUNT_SETTINGS = settings(TEST_SETTINGS, max_examples=500)764def test_discards_kill_branches():765    starts = set()766    with deterministic_PRNG():767        def test(data):768            assert runner.call_count <= 256769            while True:770                data.start_example(1)771                b = data.draw_bits(8)772                data.stop_example(b != 0)773                if len(data.buffer) == 1:774                    s = bytes(data.buffer)775                    assert s not in starts776                    starts.add(s)777                if b == 0:778                    break779        runner = ConjectureRunner(test, settings=SMALL_COUNT_SETTINGS)780        runner.run()781        assert runner.call_count == 256782@pytest.mark.parametrize("n", range(1, 32))783def test_number_of_examples_in_integer_range_is_bounded(n):784    with deterministic_PRNG():785        def test(data):786            assert runner.call_count <= 2 * n787            integer_range(data, 0, n)788        runner = ConjectureRunner(test, settings=SMALL_COUNT_SETTINGS)789        runner.run()790def test_prefix_cannot_exceed_buffer_size(monkeypatch):791    buffer_size = 10792    monkeypatch.setattr(engine_module, "BUFFER_SIZE", buffer_size)793    with deterministic_PRNG():794        def test(data):795            while data.draw_bits(1):796                assert len(data.buffer) <= buffer_size797            assert len(data.buffer) <= buffer_size798        runner = ConjectureRunner(test, settings=SMALL_COUNT_SETTINGS)799        runner.run()800        assert runner.valid_examples == buffer_size801def test_does_not_shrink_multiple_bugs_when_told_not_to():802    def test(data):803        m = data.draw_bits(8)804        n = data.draw_bits(8)805        if m > 0:806            data.mark_interesting(1)807        if n > 5:808            data.mark_interesting(2)809    with deterministic_PRNG():810        runner = ConjectureRunner(811            test, settings=settings(TEST_SETTINGS, report_multiple_bugs=False)812        )813        runner.cached_test_function([255, 255])814        runner.shrink_interesting_examples()815        results = {d.buffer for d in runner.interesting_examples.values()}816    assert len(results.intersection({bytes([0, 1]), bytes([1, 0])})) == 1817def test_does_not_keep_generating_when_multiple_bugs():818    def test(data):819        if data.draw_bits(64) > 0:820            data.draw_bits(64)821            data.mark_interesting()822    with deterministic_PRNG():823        runner = ConjectureRunner(824            test,825            settings=settings(826                TEST_SETTINGS, report_multiple_bugs=False, phases=[Phase.generate]827            ),828        )829        runner.run()830    assert runner.call_count == 2831def test_shrink_after_max_examples():832    """If we find a bug, keep looking for more, and then hit the valid-example833    limit, we should still proceed to shrinking.834    """835    max_examples = 100836    fail_at = max_examples - 5837    seen = set()838    bad = set()839    post_failure_calls = [0]840    def test(data):841        if bad:842            post_failure_calls[0] += 1843        value = data.draw_bits(8)844        if value in seen and value not in bad:845            return846        seen.add(value)847        if len(seen) == fail_at:848            bad.add(value)849        if value in bad:850            data.mark_interesting()851    # This shouldn't need to be deterministic, but it makes things much easier852    # to debug if anything goes wrong.853    with deterministic_PRNG():854        runner = ConjectureRunner(855            test,856            settings=settings(857                TEST_SETTINGS,858                max_examples=max_examples,859                phases=[Phase.generate, Phase.shrink],860                report_multiple_bugs=True,861            ),862        )863        runner.shrink_interesting_examples = Mock(name="shrink_interesting_examples")864        runner.run()865    # First, verify our test assumptions: we found a bug, kept running, and866    # then hit max-examples.867    assert runner.interesting_examples868    assert post_failure_calls[0] >= (max_examples - fail_at)869    assert runner.call_count >= max_examples870    assert runner.valid_examples == max_examples871    # Now check that we still performed shrinking, even after hitting the872    # example limit.873    assert runner.shrink_interesting_examples.call_count == 1874    assert runner.exit_reason == ExitReason.finished875def test_shrink_after_max_iterations():876    """If we find a bug, keep looking for more, and then hit the test call877    limit, we should still proceed to shrinking.878    """879    max_examples = 10880    max_iterations = max_examples * 10881    fail_at = max_iterations - 5882    invalid = set()883    bad = set()884    post_failure_calls = [0]885    def test(data):886        if bad:887            post_failure_calls[0] += 1888        value = data.draw_bits(16)889        if value in invalid:890            data.mark_invalid()891        if value in bad or (not bad and len(invalid) == fail_at):892            bad.add(value)893            data.mark_interesting()894        invalid.add(value)895        data.mark_invalid()896    # This shouldn't need to be deterministic, but it makes things much easier897    # to debug if anything goes wrong.898    with deterministic_PRNG():899        runner = ConjectureRunner(900            test,901            settings=settings(902                TEST_SETTINGS,903                max_examples=max_examples,904                phases=[Phase.generate, Phase.shrink],905                report_multiple_bugs=True,906            ),907        )908        runner.shrink_interesting_examples = Mock(name="shrink_interesting_examples")909        runner.run()910    # First, verify our test assumptions: we found a bug, kept running, and911    # then hit the test call limit.912    assert runner.interesting_examples913    assert post_failure_calls[0] >= (max_iterations - fail_at) - 1914    assert runner.call_count >= max_iterations915    assert runner.valid_examples == 0916    # Now check that we still performed shrinking, even after hitting the917    # test call limit.918    assert runner.shrink_interesting_examples.call_count == 1919    assert runner.exit_reason == ExitReason.finished920def test_populates_the_pareto_front():921    with deterministic_PRNG():922        def test(data):923            data.target_observations[""] = data.draw_bits(4)924        runner = ConjectureRunner(925            test,926            settings=settings(927                max_examples=5000,928                database=InMemoryExampleDatabase(),929                suppress_health_check=HealthCheck.all(),930            ),931            database_key=b"stuff",932        )933        runner.run()934        assert len(runner.pareto_front) == 2 ** 4935def test_pareto_front_contains_smallest_valid_when_not_targeting():936    with deterministic_PRNG():937        def test(data):938            data.draw_bits(4)939        runner = ConjectureRunner(940            test,941            settings=settings(942                max_examples=5000,943                database=InMemoryExampleDatabase(),944                suppress_health_check=HealthCheck.all(),945            ),946            database_key=b"stuff",947        )948        runner.run()949        assert len(runner.pareto_front) == 1950def test_pareto_front_contains_different_interesting_reasons():951    with deterministic_PRNG():952        def test(data):953            data.mark_interesting(data.draw_bits(4))954        runner = ConjectureRunner(955            test,956            settings=settings(957                max_examples=5000,958                database=InMemoryExampleDatabase(),959                suppress_health_check=HealthCheck.all(),960            ),961            database_key=b"stuff",962        )963        runner.run()964        assert len(runner.pareto_front) == 2 ** 4965def test_database_contains_only_pareto_front():966    with deterministic_PRNG():967        def test(data):968            data.target_observations["1"] = data.draw_bits(4)969            data.draw_bits(64)970            data.target_observations["2"] = data.draw_bits(8)971        db = InMemoryExampleDatabase()972        runner = ConjectureRunner(973            test,974            settings=settings(975                max_examples=500, database=db, suppress_health_check=HealthCheck.all()976            ),977            database_key=b"stuff",978        )979        runner.run()980        assert len(runner.pareto_front) <= 500981        for v in runner.pareto_front:982            assert v.status >= Status.VALID983        assert len(db.data) == 1984        (values,) = db.data.values()985        values = set(values)986        assert len(values) == len(runner.pareto_front)987        for data in runner.pareto_front:988            assert data.buffer in values989            assert data in runner.pareto_front990        for k in values:991            assert runner.cached_test_function(k) in runner.pareto_front992def test_clears_defunct_pareto_front():993    with deterministic_PRNG():994        def test(data):995            data.draw_bits(8)996            data.draw_bits(8)997        db = InMemoryExampleDatabase()998        runner = ConjectureRunner(999            test,1000            settings=settings(1001                max_examples=10000,1002                database=db,1003                suppress_health_check=HealthCheck.all(),1004                phases=[Phase.reuse],1005            ),1006            database_key=b"stuff",1007        )1008        for i in range(256):1009            db.save(runner.pareto_key, bytes([i, 0]))1010        runner.run()1011        assert len(list(db.fetch(runner.pareto_key))) == 11012def test_replaces_all_dominated():1013    def test(data):1014        data.target_observations["m"] = 3 - data.draw_bits(2)1015        data.target_observations["n"] = 3 - data.draw_bits(2)1016    runner = ConjectureRunner(1017        test,1018        settings=settings(TEST_SETTINGS, database=InMemoryExampleDatabase()),1019        database_key=b"stuff",1020    )1021    d1 = runner.cached_test_function([0, 1]).as_result()1022    d2 = runner.cached_test_function([1, 0]).as_result()1023    assert len(runner.pareto_front) == 21024    assert runner.pareto_front[0] == d11025    assert runner.pareto_front[1] == d21026    d3 = runner.cached_test_function([0, 0]).as_result()1027    assert len(runner.pareto_front) == 11028    assert runner.pareto_front[0] == d31029def test_does_not_duplicate_elements():1030    def test(data):1031        data.target_observations["m"] = data.draw_bits(8)1032    runner = ConjectureRunner(1033        test,1034        settings=settings(TEST_SETTINGS, database=InMemoryExampleDatabase()),1035        database_key=b"stuff",1036    )1037    d1 = runner.cached_test_function([1]).as_result()1038    assert len(runner.pareto_front) == 11039    # This can happen in practice if we e.g. reexecute a test because it has1040    # expired from the cache. It's easier just to test it directly though1041    # rather than simulate the failure mode.1042    is_pareto = runner.pareto_front.add(d1)1043    assert is_pareto1044    assert len(runner.pareto_front) == 11045def test_includes_right_hand_side_targets_in_dominance():1046    def test(data):1047        if data.draw_bits(8):1048            data.target_observations[""] = 101049    runner = ConjectureRunner(1050        test,1051        settings=settings(TEST_SETTINGS, database=InMemoryExampleDatabase()),1052        database_key=b"stuff",1053    )1054    d1 = runner.cached_test_function([0]).as_result()1055    d2 = runner.cached_test_function([1]).as_result()1056    assert dominance(d1, d2) == DominanceRelation.NO_DOMINANCE1057def test_smaller_interesting_dominates_larger_valid():1058    def test(data):1059        if data.draw_bits(8) == 0:1060            data.mark_interesting()1061    runner = ConjectureRunner(1062        test,1063        settings=settings(TEST_SETTINGS, database=InMemoryExampleDatabase()),1064        database_key=b"stuff",1065    )1066    d1 = runner.cached_test_function([0]).as_result()1067    d2 = runner.cached_test_function([1]).as_result()1068    assert dominance(d1, d2) == DominanceRelation.LEFT_DOMINATES1069def test_runs_full_set_of_examples():1070    def test(data):1071        data.draw_bits(64)1072    runner = ConjectureRunner(1073        test,1074        settings=settings(TEST_SETTINGS, database=InMemoryExampleDatabase()),1075        database_key=b"stuff",1076    )1077    runner.run()1078    assert runner.valid_examples == TEST_SETTINGS.max_examples1079def test_runs_optimisation_even_if_not_generating():1080    def test(data):1081        data.target_observations["n"] = data.draw_bits(16)1082    with deterministic_PRNG():1083        runner = ConjectureRunner(1084            test, settings=settings(TEST_SETTINGS, phases=[Phase.target])1085        )1086        runner.cached_test_function(bytes(2))1087        runner.run()1088        assert runner.best_observed_targets["n"] == (2 ** 16) - 11089def test_runs_optimisation_once_when_generating():1090    def test(data):1091        data.target_observations["n"] = data.draw_bits(16)1092    with deterministic_PRNG():1093        runner = ConjectureRunner(1094            test, settings=settings(TEST_SETTINGS, max_examples=100)1095        )1096        runner.optimise_targets = Mock(name="optimise_targets")1097        try:1098            runner.generate_new_examples()1099        except RunIsComplete:1100            pass1101        assert runner.optimise_targets.call_count == 11102def test_does_not_run_optimisation_when_max_examples_is_small():1103    def test(data):1104        data.target_observations["n"] = data.draw_bits(16)1105    with deterministic_PRNG():1106        runner = ConjectureRunner(1107            test, settings=settings(TEST_SETTINGS, max_examples=10)1108        )1109        runner.optimise_targets = Mock(name="optimise_targets")1110        try:1111            runner.generate_new_examples()1112        except RunIsComplete:1113            pass1114        assert runner.optimise_targets.call_count == 01115def test_does_not_cache_extended_prefix():1116    def test(data):1117        data.draw_bits(64)1118    with deterministic_PRNG():1119        runner = ConjectureRunner(test, settings=TEST_SETTINGS)1120        d1 = runner.cached_test_function(b"", extend=8)1121        d2 = runner.cached_test_function(b"", extend=8)1122        assert d1.status == d2.status == Status.VALID1123        assert d1.buffer != d2.buffer1124def test_does_cache_if_extend_is_not_used():1125    calls = [0]1126    def test(data):1127        calls[0] += 11128        data.draw_bits(8)1129    with deterministic_PRNG():1130        runner = ConjectureRunner(test, settings=TEST_SETTINGS)1131        d1 = runner.cached_test_function(b"\0", extend=8)1132        d2 = runner.cached_test_function(b"\0", extend=8)1133        assert d1.status == d2.status == Status.VALID1134        assert d1.buffer == d2.buffer1135        assert calls[0] == 11136def test_does_result_for_reuse():1137    calls = [0]1138    def test(data):1139        calls[0] += 11140        data.draw_bits(8)1141    with deterministic_PRNG():1142        runner = ConjectureRunner(test, settings=TEST_SETTINGS)1143        d1 = runner.cached_test_function(b"\0", extend=8)1144        d2 = runner.cached_test_function(d1.buffer)1145        assert d1.status == d2.status == Status.VALID1146        assert d1.buffer == d2.buffer1147        assert calls[0] == 11148def test_does_not_cache_overrun_if_extending():1149    def test(data):1150        data.draw_bits(64)1151    with deterministic_PRNG():1152        runner = ConjectureRunner(test, settings=TEST_SETTINGS)1153        d1 = runner.cached_test_function(b"", extend=4)1154        d2 = runner.cached_test_function(b"", extend=8)1155        assert d1.status == Status.OVERRUN1156        assert d2.status == Status.VALID1157def test_does_cache_overrun_if_not_extending():1158    def test(data):1159        data.draw_bits(64)1160        data.draw_bits(64)1161    with deterministic_PRNG():1162        runner = ConjectureRunner(test, settings=TEST_SETTINGS)1163        d1 = runner.cached_test_function(bytes(8), extend=0)1164        d2 = runner.cached_test_function(bytes(8), extend=8)1165        assert d1.status == Status.OVERRUN1166        assert d2.status == Status.VALID1167def test_does_not_cache_extended_prefix_if_overrun():1168    def test(data):1169        data.draw_bits(64)1170    with deterministic_PRNG():1171        runner = ConjectureRunner(test, settings=TEST_SETTINGS)1172        d1 = runner.cached_test_function(b"", extend=4)1173        d2 = runner.cached_test_function(b"", extend=8)1174        assert d1.status == Status.OVERRUN1175        assert d2.status == Status.VALID1176def test_can_be_set_to_ignore_limits():1177    def test(data):1178        data.draw_bits(8)1179    with deterministic_PRNG():1180        runner = ConjectureRunner(1181            test, settings=settings(TEST_SETTINGS, max_examples=1), ignore_limits=True1182        )1183        for c in range(256):1184            runner.cached_test_function([c])...

test_optimiser.py

Source:test_optimiser.py

...25            data.target_observations["m"] = data.draw_bits(8)26        runner = ConjectureRunner(test, settings=TEST_SETTINGS)27        runner.cached_test_function([0])28        try:29            runner.optimise_targets()30        except RunIsComplete:31            pass32        assert runner.best_observed_targets["m"] == 25533def test_optimises_multiple_targets():34    with deterministic_PRNG():35        def test(data):36            n = data.draw_bits(8)37            m = data.draw_bits(8)38            if n + m > 256:39                data.mark_invalid()40            data.target_observations["m"] = m41            data.target_observations["n"] = n42            data.target_observations["m + n"] = m + n43        runner = ConjectureRunner(test, settings=TEST_SETTINGS)44        runner.cached_test_function([200, 0])45        runner.cached_test_function([0, 200])46        try:47            runner.optimise_targets()48        except RunIsComplete:49            pass50        assert runner.best_observed_targets["m"] == 25551        assert runner.best_observed_targets["n"] == 25552        assert runner.best_observed_targets["m + n"] == 25653def test_optimises_when_last_element_is_empty():54    with deterministic_PRNG():55        def test(data):56            data.target_observations["n"] = data.draw_bits(8)57            data.start_example(1)58            data.stop_example(1)59        runner = ConjectureRunner(test, settings=TEST_SETTINGS)60        runner.cached_test_function([250])61        try:62            runner.optimise_targets()63        except RunIsComplete:64            pass65        assert runner.best_observed_targets["n"] == 25566def test_can_optimise_last_with_following_empty():67    with deterministic_PRNG():68        def test(data):69            for _ in range(100):70                data.draw_bits(2)71            data.target_observations[""] = data.draw_bits(8)72            data.start_example(1)73            data.stop_example()74        runner = ConjectureRunner(75            test, settings=settings(TEST_SETTINGS, max_examples=100)76        )77        runner.cached_test_function(bytes(101))78        with pytest.raises(RunIsComplete):79            runner.optimise_targets()80        assert runner.best_observed_targets[""] == 25581@pytest.mark.parametrize("lower, upper", [(0, 1000), (13, 100), (1000, 2 ** 16 - 1)])82@pytest.mark.parametrize("score_up", [False, True])83def test_can_find_endpoints_of_a_range(lower, upper, score_up):84    with deterministic_PRNG():85        def test(data):86            n = data.draw_bits(16)87            if n < lower or n > upper:88                data.mark_invalid()89            if not score_up:90                n = -n91            data.target_observations["n"] = n92        runner = ConjectureRunner(93            test, settings=settings(TEST_SETTINGS, max_examples=1000)94        )95        runner.cached_test_function(int_to_bytes((lower + upper) // 2, 2))96        try:97            runner.optimise_targets()98        except RunIsComplete:99            pass100        if score_up:101            assert runner.best_observed_targets["n"] == upper102        else:103            assert runner.best_observed_targets["n"] == -lower104def test_targeting_can_drive_length_very_high():105    with deterministic_PRNG():106        def test(data):107            count = 0108            while data.draw_bits(2) == 3:109                count += 1110            data.target_observations[""] = min(count, 100)111        runner = ConjectureRunner(test, settings=TEST_SETTINGS)112        runner.cached_test_function(bytes(10))113        try:114            runner.optimise_targets()115        except RunIsComplete:116            pass117        assert runner.best_observed_targets[""] == 100118def test_optimiser_when_test_grows_buffer_to_invalid():119    with deterministic_PRNG():120        def test(data):121            m = data.draw_bits(8)122            data.target_observations["m"] = m123            if m > 100:124                data.draw_bits(16)125                data.mark_invalid()126        runner = ConjectureRunner(test, settings=TEST_SETTINGS)127        runner.cached_test_function(bytes(10))128        try:129            runner.optimise_targets()130        except RunIsComplete:131            pass132        assert runner.best_observed_targets["m"] == 100133def test_can_patch_up_examples():134    with deterministic_PRNG():135        def test(data):136            data.start_example(42)137            m = data.draw_bits(6)138            data.target_observations["m"] = m139            for _ in range(m):140                data.draw_bits(1)141            data.stop_example()142            for i in range(4):143                if i != data.draw_bits(8):144                    data.mark_invalid()145        runner = ConjectureRunner(test, settings=TEST_SETTINGS)146        d = runner.cached_test_function([0, 0, 1, 2, 3, 4])147        assert d.status == Status.VALID148        try:149            runner.optimise_targets()150        except RunIsComplete:151            pass152        assert runner.best_observed_targets["m"] == 63153def test_optimiser_when_test_grows_buffer_to_overflow():154    with deterministic_PRNG():155        with buffer_size_limit(2):156            def test(data):157                m = data.draw_bits(8)158                data.target_observations["m"] = m159                if m > 100:160                    data.draw_bits(64)161                    data.mark_invalid()162            runner = ConjectureRunner(test, settings=TEST_SETTINGS)163            runner.cached_test_function(bytes(10))164            try:165                runner.optimise_targets()166            except RunIsComplete:167                pass...

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