def test_get_edge_bad_input(self):
g = Graph()
assert g.get_edge(None, None) is None
assert g.get_edge(None, v) is None
assert g.get_edge(v, None) is None
assert g.get_edge(v, 'fs') is None
assert g.get_edge(v, 3) is None
def test_bfs_visit(self):
def visit(node):
visited.add(node)
visited = set()
g = Graph([v, w, x, y], [vw, vx, wx])
g.bfs(v, visit)
assert set([v, w, x]) == visited
def test_add_regular_edges_invalid(self):
g = Graph([v, w, x])
# degree > vertexcount-1
with pytest.raises(GraphException):
g.add_regular_edges(3)
# degree * vertexcount not even
with pytest.raises(GraphException):
g.add_regular_edges(1)
def test_add_regular_edges_0(self):
g = Graph()
g.add_regular_edges(0)
assert g.vertices() == []
assert g.edges() == []
g = Graph([v, w, x])
g.add_regular_edges(0)
assert sorted(g.vertices()) == sorted([v, x, w])
assert g.edges() == []
def test_size(self):
assert 0 == Graph().size()
assert 1 == Graph([v, w], [vw, ]).size()
print('hi')
for n in range(8):
print(n)
g = Graph(make_vertices(n))
g.add_all_edges()
assert (n * (n - 1)) // 2 == g.size()
def test_del_vertex(self):
g = Graph([v, w, x], [vw, vx, wx])
g.del_vertex(x)
assert g == Graph([v, w], [vw])
g.del_vertex(v)
assert g == Graph([w, ], [])
g.del_vertex(w)
assert g == Graph([], [])
def test_get_edge_false(self):
g = Graph()
assert None is g.get_edge(v, v)
assert None is g.get_edge(w, w)
assert None is g.get_edge(v, w)
assert None is g.get_edge(w, v)
g = Graph([v, w])
assert None is g.get_edge(v, v)
assert None is g.get_edge(w, w)
assert None is g.get_edge(v, w)
assert None is g.get_edge(w, v)
g = Graph([v, w, x], [vx, ])
assert None is g.get_edge(v, v)
assert None is g.get_edge(w, w)
assert None is g.get_edge(v, w)
assert None is g.get_edge(w, v)
def test_add_all_edges(self):
g = Graph([v, x, w])
g.add_all_edges()
assert sorted(g.vertices()) == sorted([v, x, w])
assert len(g.edges()) == 3
def test_add_all_edges_empty(self):
g = Graph()
g.add_all_edges()
assert g.vertices() == []
assert g.edges() == []
def test_add_regular_edges_odd(self):
g = Graph([v, w, x, y])
g.add_regular_edges(1)
def test_bfs(self):
g = Graph([v, w, x, y], [vw, vx, wx])
assert set([v, w, x]) == g.bfs(v)
assert set([v, w, x]) == g.bfs(w)
assert set([y, ]) == g.bfs(y)
def test_remove_edge_notthere(self):
g = Graph([v, w, x], [vw, vx])
g.del_edge(wx)
assert g == Graph([v, w, x], [vw, vx])
def test_del_edge(self):
g = Graph([v, w, x], [vw, vx])
g.del_edge(vx)
assert g == Graph([v, w, x], [vw])
g.del_edge(wv) # backwards vw
assert g == Graph([v, w, x], [])
def test_get_edge_true(self):
g = Graph([v, w], [vw, ])
assert vw == g.get_edge(v, w)
assert vw == g.get_edge(w, v)
def test_add_regular_edges_even(self):
g = Graph([v, w, x])
g.add_regular_edges(2)
assert set(g.edges()) == set([vw, vx, wx])
def test_out_edges_none(self):
g = Graph()
assert [] == g.out_edges(v)
def test_edges(self):
g = Graph([v, w], [vw, ])
assert g.edges() == [vw, ]
g = Graph([v, w, x], [vw, vx])
assert set(g.edges()) == set([vx, vw])
def test_vertices(self):
g = Graph([v, w], [vw, ])
assert sorted(g.vertices()) == sorted([v, w])
def test_order(self):
assert 0 == Graph().order()
assert 1 == Graph([v, ]).order()
assert 4 == Graph([v, w, x, y]).order()
g = Graph(make_vertices(10))
assert 10 == g.order()
def test_add_regular_edges_negative(self):
g = Graph()
with pytest.raises(ValueError):
g.add_regular_edges(-1)
def test_out_edges(self):
g = Graph([v, w, x], [vw, vx])
assert sorted(g.out_edges(v)) == sorted([vw, vx])
assert g.out_edges(w) == [vw, ]
assert g.out_edges(x) == [vx, ]
def test_del_vertex_notthere(self):
g = Graph([v, w, x], [vw, vx, wx])
g.del_vertex(y)
assert g == Graph([v, w, x], [vw, vx, wx])