def test_get__non_existing_element_no_default_provided__none_returned(faker):
sut = HashTable()
in_key = random.randrange(1000)
out_value = sut.get(in_key)
assert out_value is None
def test_add__collisioning_elements__ok(faker):
initial_size = 10
# Build random string whose hash could match in the hashtable
keys = [
"".join(random.choices(string.ascii_uppercase + string.digits, k=10))
for _ in range(10000)
]
group_keys_by_hash = itertools.groupby(
keys, key=lambda e: hash(e) % initial_size)
# Select the group of values with more collisions
max_group = max(((k, list(g)) for k, g in group_keys_by_hash),
key=lambda g: len(g[1]))
if len(max_group[1]) < 2:
pytest.skip("No duplicated hash found. Skipping...")
sut = HashTable(initial_size)
key1 = max_group[1][0]
key2 = max_group[1][1]
exp_val1 = str(key1)
exp_val2 = str(key2)
# Add two keys with expected same hash cell
sut.add(key1, exp_val1)
sut.add(key2, exp_val2)
out_key1 = sut.get(key1)
out_key2 = sut.get(key2)
assert key1 != key2
assert out_key1 == exp_val1
assert out_key2 == exp_val2
def test_get__non_existing_element_default_provided__default_returned(faker, ):
sut = HashTable()
in_key = random.randrange(1000)
expected_out = faker.pystr()
actual_out = sut.get(in_key, default_value=expected_out)
assert actual_out is expected_out
def test_add__non_existing_element__inserted(faker):
sut = HashTable()
in_key = random.randrange(1000)
in_value = faker.pystr()
assert in_key not in sut
sut.add(in_key, in_value)
out_value = sut.get(in_key)
assert in_value == out_value
def test_add__existing_element__updated(faker):
sut = HashTable()
in_key = random.randrange(1000)
insert_value = faker.pystr()
sut.add(in_key, insert_value)
assert in_key in sut
update_value = faker.pystr()
sut.add(in_key, update_value)
out_value = sut.get(in_key)
assert update_value == out_value