def test_discard_only_removes_one_element(a):
t = TopoSet(a)
sizes = [len(t)]
for item in a:
t.discard(item)
sizes.append(len(t))
assert all(a == b + 1 for a, b in pairwise(sizes))
def test_discarding_all_elements_results_in_an_empty_set(a):
t = TopoSet(a)
for item in a:
t.discard(item)
assert len(t) == 0
def test_non_containment_negative(a, b):
included = a - b
t = TopoSet(included)
assert all(not (item not in t) for item in included)
def test_default_constructed_toposet_is_empty():
t = TopoSet()
assert len(t) == 0
def test_non_containment_positive(a, b):
included = a - b
excluded = b - a
t = TopoSet(included)
assert all(item not in t for item in excluded)
def test_containment_negative(a, b):
included = a - b
excluded = b - a
t = TopoSet(included)
assert all(not (item in t) for item in excluded)
def test_containment_positive(a, b):
included = a - b
t = TopoSet(included)
assert all(item in t for item in included)
def test_toposet_with_items_added_from_a_set_is_equal_to_the_set(items):
t = TopoSet()
for item in items:
t.add(item)
assert t == items
def test_toposet_construction_eliminates_duplicates(item, size):
t = TopoSet([item] * size)
assert list(t) == [item]
def test_toposet_eliminates_duplicates(items):
t = TopoSet(items)
t.update(items)
assert list(t) == items
def test_toposet_updated_from_iterable_without_duplicates_has_same_length(
items):
t = TopoSet()
for item in items:
t.add(item)
assert list(t) == items
def test_toposet_updated_from_iterable_without_duplicates_has_same_length(
items):
t = TopoSet()
t.update(items)
assert list(t) == items
def test_default_constructed_toposet_contains_no_items():
t = TopoSet()
assert list(t) == []
def test_removing_an_item_not_present_silently_succeeds(a):
b = max(a) + 1
t = TopoSet(a)
with raises(KeyError):
t.remove(b)
def test_discarding_an_item_not_present_silently_succeeds(a):
b = max(a) + 1
t = TopoSet(a)
t.discard(b)
