def test_keeps_using_solid_passes_while_they_shrink_size():
good = {
hbytes([0, 1, 2, 3, 4, 5]),
hbytes([0, 1, 2, 3, 5]),
hbytes([0, 1, 3, 5]),
hbytes([1, 3, 5]),
hbytes([1, 5]),
}
initial = max(good, key=sort_key)
@shrinking_from(initial)
def shrinker(data):
while True:
data.draw_bits(8)
if hbytes(data.buffer) in good:
data.mark_interesting()
shrinker.clear_passes()
d1 = shrinker.add_new_pass(block_program('X'))
d2 = shrinker.add_new_pass(block_program('-'))
for _ in range(3):
shrinker.single_greedy_shrink_iteration()
assert d1.classification == PassClassification.HOPEFUL
assert d2.classification == PassClassification.CANDIDATE
def test_block_deletion_can_delete_short_ranges(monkeypatch):
@shrinking_from([
v for i in range(5) for _ in range(i + 1) for v in [0, i]]
)
def shrinker(data):
while True:
n = data.draw_bits(16)
for _ in range(n):
if data.draw_bits(16) != n:
data.mark_invalid()
if n == 4:
data.mark_interesting()
for i in range(1, 5):
block_program('X' * i)(shrinker)
assert list(shrinker.shrink_target.buffer) == [0, 4] * 5
def test_will_enable_previously_bad_passes_when_failing_to_shrink():
# We lead the shrinker down the garden path a bit where it keeps making
# progress but only lexically. When it finally gets down to the minimum
good = {
hbytes([1, 2, 3, 4, 5, 6]),
hbytes([1, 2, 3, 4, 5, 5]),
hbytes([1, 2, 2, 4, 5, 5]),
hbytes([1, 2, 2, 4, 4, 5]),
hbytes([0, 2, 2, 4, 4, 5]),
hbytes([0, 1, 2, 4, 4, 5]),
}
initial = max(good)
final = min(good)
@shrinking_from(initial + hbytes([0, 7]))
def shrinker(data):
string = hbytes([data.draw_bits(8) for _ in range(6)])
if string in good:
n = 0
while data.draw_bits(8) != 7:
n += 1
if not (string == final or n > 0):
data.mark_invalid()
data.mark_interesting()
# In order to get to the minimized result we want to run both of these,
# but the second pass starts out as disabled (and anyway won't work until
# the first has hit fixity).
shrinker.clear_passes()
shrinker.add_new_pass(block_program('-'))
shrinker.add_new_pass(block_program('X'))
shrinker.shrink()
assert shrinker.shrink_target.buffer == final + hbytes([7])
def test_passes_can_come_back_to_life():
initial = hbytes([1, 2, 3, 4, 5, 6])
buf1 = hbytes([0, 1, 3, 4, 5, 6])
buf2 = hbytes([0, 1, 3, 4, 4, 6])
good = {
initial, buf1, buf2
}
@shrinking_from(initial)
def shrinker(data):
string = hbytes([data.draw_bits(8) for _ in range(6)])
if string in good:
data.mark_interesting()
shrinker.clear_passes()
shrinker.add_new_pass(block_program('--'))
shrinker.add_new_pass(block_program('-'))
shrinker.single_greedy_shrink_iteration()
assert shrinker.shrink_target.buffer == buf1
shrinker.single_greedy_shrink_iteration()
assert shrinker.shrink_target.buffer == buf2