def test_same_relationship_will_overwrite():
g = Graph()
g.relate(10, "is more than", 4)
g.relate(10, "is more than", 2)
assert set(g.nodes()) == {2, 4, 10}
assert len(list(g.match())) == 2
g.relate(10, "is more than", 2)
assert set(g.nodes()) == {2, 4, 10}
assert len(list(g.match())) == 2
def test_is_related():
g = Graph()
g.relate(10, "is more than", 4)
g.relate(10, "is more than", 2)
g.relate(10, "is less than", 20)
g.relate(20, "is less than", 30)
assert g.is_related(10, "is less than", 20)
assert not g.is_related(20, "is more than", 4)
def test_removal_of_non_existent_node_should_fail():
g = Graph()
g.add(10)
assert set(g.nodes()) == {10}
try:
g.remove(12)
except KeyError:
assert True
else:
assert False
def test_can_remove():
g = Graph()
g.add(10)
assert set(g.nodes()) == {10}
g.remove(10)
assert set(g.nodes()) == set()
def test_can_separate():
g = Graph()
g.relate(10, "is more than", 4)
g.relate(10, "is more than", 2)
g.relate(10, "is less than", 20)
g.relate(20, "is less than", 30)
g.separate(10, "is less than", 20)
assert set(g.nodes()) == {2, 4, 10, 20, 30}
assert len(list(g.match())) == 3
assert len(list(g.match(10))) == 2
assert len(list(g.match(20))) == 1
assert len(list(g.match(30))) == 0
assert len(list(g.match(None, "is less than"))) == 1
assert len(list(g.match(None, "is more than"))) == 2
assert len(list(g.match(None, "is equal to"))) == 0
assert len(list(g.match(None, None, 2))) == 1
assert len(list(g.match(None, None, 4))) == 1
assert len(list(g.match(None, None, 20))) == 0
assert len(list(g.match(None, None, 30))) == 1
assert len(list(g.match(10, "is more than"))) == 2
assert len(list(g.match(20, "is more than"))) == 0
assert len(list(g.match(20, "is less than", 30))) == 1
assert len(list(g.match(20, "is less than", 40))) == 0
def test_removal_of_related_node_should_fail():
g = Graph()
g.relate(10, "is more than", 4)
assert set(g.nodes()) == {4, 10}
try:
g.remove(10)
except NotIsolatedError:
assert True
else:
assert False
g.separate(10, "is more than", 4)
g.remove(10)
assert set(g.nodes()) == {4}
