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
