def test_add_edge():
a = Vertex("a")
b = Vertex("b")
e = Edge(a, b)
t = Graph([a, b], [])
t.add_edge(e)
assert t[a][b] == e
assert t[b][a] == e
assert t.edge_count == 1
def test_create_unconnected_graph():
a = Vertex(1)
t = Graph.unconnected([a])
assert isinstance(t, Graph)
assert t.vertex_count == 1
assert t.edge_count == 0
assert len(list(t.keys())) == 1
def test_create_odd_connected_graph_odd_graph():
PASSED = False
vs = [Vertex(x) for x in "abcde"]
try:
t = Graph.regular_connected(vs, 3)
except AssertionError:
PASSED = True
if PASSED:
assert True
else:
assert False
def test_create_odd_connected_graph_even_graph():
vs = [Vertex(x) for x in "abcd"]
t = Graph.regular_connected(vs, 3)
assert t.vertex_count == 4
assert t.edge_count == 6
def test_create_fully_connected_graph():
vs = [Vertex(x) for x in "abcdef"]
t = Graph.fully_connected(vs)
assert t.vertex_count == 6
assert t.edge_count == 15
def test_str():
a = Vertex("a")
b = Vertex("b")
e = Edge(a, b)
t = Graph([a, b], [e])
assert t.__str__() == "Graph contains 2 vertices and 1 edge"
def test_add_vertex():
t = Graph([], [])
a = Vertex("a")
t.add_vertex(a)
assert type(t[a]) == dict
assert t.vertex_count == 1