def test_connected_component():
edge0 = Edge(0, 1)
edge1 = Edge(2, 3)
edges = [edge0, edge1]
g = BaseGraph(edges)
assert connected_component(g, 0) == BaseGraph([edge0])
assert connected_component(g, 2) == BaseGraph([edge1])
def test_intersection():
graph0 = BaseGraph([Edge(i, i + 1) for i in range(2)])
graph1 = BaseGraph([Edge(0, 1)])
graph2 = BaseGraph([Edge("a", "b")])
graph01 = graph0 * graph1
graph02 = graph0 * graph2
assert graph01.edges == set([Edge(0, 1)])
assert graph02.edges == set()
def test_vertices():
edges = [Edge(i, i + 1) for i in range(3)]
graph = BaseGraph(edges)
vertices = []
for i in graph.vertices:
vertices.append(i)
assert len(vertices) == 4
def test_neighborhood():
edges = [Edge(0, 1)]
g = BaseGraph(edges)
assert neighborhood(g, 0) == g
assert neighborhood(g, 1) == BaseGraph()
def test_subtract():
graph = BaseGraph([Edge(0, 1)])
zero_graph = graph - graph
assert zero_graph.edges == set()
def test_add():
graph0 = BaseGraph([Edge(0, 1)])
graph1 = BaseGraph([Edge(1, 2)])
sum_graph = graph0 + graph1
assert sum_graph.edges == set([Edge(i, i + 1) for i in range(2)])
def test_extend():
graph = BaseGraph()
edges = [Edge(i, i + 1) for i in range(2)]
graph.extend(edges)
assert graph.edges == set([Edge(i, i + 1) for i in range(2)])
def test_append():
graph = BaseGraph()
edge = Edge(source="a", target="b")
graph.append(edge)
assert graph.edges == set([edge])
def test_size():
edges = [Edge(i, i + 1) for i in range(3)]
graph = BaseGraph(edges)
assert graph.size == 3
def test_order():
edges = [Edge(i, i + 1) for i in range(3)]
graph = BaseGraph(edges)
assert graph.order == 4
def test_nonempty_graph():
edges = [Edge(i, i + 1) for i in range(3)]
graph = BaseGraph(edges)
assert graph.edges == set([Edge(i, i + 1) for i in range(3)])
def test_unhashable_edge():
source = set()
target = "b"
edge = Edge(source=source, target=target)
with pytest.raises(ValueError):
BaseGraph([edge])
def test_empty_graph():
graph = BaseGraph()
assert graph.edges == set()
def test_not_equals():
g = BaseGraph()
h = BaseGraph([Edge("a", "b")])
assert g != h
def test_contains():
edge = Edge(0, 1)
non_edge = Edge("a", "b")
graph = BaseGraph([edge])
assert edge in graph.edges
assert non_edge not in graph.edges