def test_graph_from_edges_string():
edges_strings = [
"A - B - C ; D - C",
"A - B ; B - C ; D - C",
"A -> B -> C ; D -> C",
"A-B;B-C;D-C",
"A->B;B->C;D-C;",
]
for edges_string in edges_strings:
G = graph_from_edges_string(edges_string)
assert set(G.nodes) == {"A", "B", "C", "D"}
assert set(G.edges) == {("A", "B"), ("B", "C"), ("D", "C")}
edges2 = edges_from_graph(G)
G2 = graph_from_edges(*edges2)
assert set(G2.nodes) == set(G.nodes)
assert set(G2.edges) == set(G.edges)
edges_strings = ["1 - 2 - 3 ; 4 - 3", "1 - 2 ; 2 - 3 ; 4 - 3"]
for edges_string in edges_strings:
G = graph_from_edges_string(edges_string)
assert set(G.nodes) == {1, 2, 3, 4}
assert set(G.edges) == {(1, 2), (2, 3), (4, 3)}
edges2 = edges_from_graph(G)
G2 = graph_from_edges(*edges2)
assert set(G2.nodes) == set(G.nodes)
assert set(G2.edges) == set(G.edges)
def test_remove_node_keep_connections():
G = graph_from_edges_string("A - B - C; D - C")
G = remove_node_keep_connections(G, "B")
assert set(G.edges) == {("A", "C"), ("D", "C")}
assert set(G.nodes) == {"A", "C", "D"}
G = graph_from_edges_string("A - B - C; D - C")
G = remove_node_keep_connections(G, "A")
assert set(G.edges) == {("B", "C"), ("D", "C")}
assert set(G.nodes) == {"B", "C", "D"}
G = graph_from_edges_string("A - B - C - E; D - C - E")
G = remove_node_keep_connections(G, "C")
assert set(G.edges) == {("A", "B"), ("B", "E"), ("D", "E")}
assert set(G.nodes) == {"A", "B", "D", "E"}
G = graph_from_edges_string("A - B - C - D; C - E")
G = remove_node_keep_connections(G, "C")
assert set(G.edges) == {("A", "B"), ("B", "D"), ("B", "E")}
assert set(G.nodes) == {"A", "B", "D", "E"}
G = graph_from_edges_string("A - C - D; B - C - E")
G = remove_node_keep_connections(G, "C")
assert set(G.edges) == {("A", "D"), ("A", "E"), ("B", "D"), ("B", "E")}
assert set(G.nodes) == {"A", "B", "D", "E"}
def test_insert_node_above():
G = graph_from_edges_string("1 - 2 - 3")
G2 = insert_node_above(G, 1, 0)
assert G is G2
assert set(G2.nodes) == {0, 1, 2, 3}
assert set(G2.edges) == {(0, 1), (1, 2), (2, 3)}
G = insert_node_above(G, 2, 22)
assert set(G.nodes) == {0, 1, 2, 3, 22}
assert set(G.edges) == {(0, 1), (1, 22), (22, 2), (2, 3)}
G = graph_from_edges_string("1 - 2 - 3; 4 - 3")
G = insert_node_above(G, 3, 33)
assert set(G.edges) == {(1, 2), (2, 33), (4, 33), (33, 3)}
assert set(G.nodes) == {1, 2, 3, 4, 33}
def test_get_connected_graph():
G = graph_from_edges_string("A - B ; B - C")
Gs = get_connected_graphs(G)
assert len(Gs) == 1
assert Gs[0] == G
def gequal(g1, g2):
if set(g1.nodes) != set(g2.nodes):
return False
if set(g1.edges) != set(g2.edges):
return False
return True
G = graph_from_edges_string("A - B; C - D")
Gs = get_connected_graphs(G)
assert len(Gs) == 2
g1, g2 = graph_from_edges_string("A - B"), graph_from_edges_string("C - D")
G1, G2 = Gs
assert (gequal(g1, G1) and gequal(g2, G2)) or (gequal(g1, G2)
and gequal(g2, G1))
def test_has_cycle():
G = graph_from_edges_string("A - B - C; D - C")
assert not has_cycle(G)
G = graph_from_edges_string("A - B - C - A")
assert has_cycle(G)
