def test_duplicate_edge(self):
g = Graph()
g.addNode(Node('A'))
g.addNode(Node('B'))
g.addEdge(Edge(Node('A'), Node('B'))) # A --> B
with self.assertRaises(ValueError) as context:
g.addEdge(Edge(Node('A'),Node('B')))
self.assertTrue('The edge (Node: A, Node: B) is already in the graph' in context.exception)
def test_add_edge(self):
g = Graph()
n1 = Node('A')
n2 = Node('B')
g.addNode(n1)
g.addNode(n2)
g.addEdge(Edge(n1, n2)) # A --> B
self.assertIn(n2, g.edges[n1])
self.assertEqual([], g.edges[n2])
def test_edge_added_from_to__non_existing_node(self):
"""Test case: Check when an edge is added from or to a non existing node
"""
g = Graph()
g.addNode(Node('A'))
g.addNode(Node('B'))
with self.assertRaises(ValueError) as context:
g.addEdge(Edge(Node('A'), Node('D'))) # A --> D
g.addEdge(Edge(Node('D'), Node('A'))) # D --> A
self.assertTrue('Node: A and Node: D must be in the graph' in context.exception)
def test_method_getitem_of_Graph(self):
"""Test case:
* Nodes A, B. C, D. Neighbors of A: B and D
"""
g = Graph()
g.addNode(Node('A'))
g.addNode(Node('B'))
g.addNode(Node('C'))
g.addNode(Node('D'))
g.addEdge(Edge(Node('A'), Node('B'))) # A --> B
g.addEdge(Edge(Node('A'), Node('D'))) # A --> D
self.assertIn(Node('B'), g[Node('A')])
self.assertIn(Node('D'), g[Node('A')])
def test_edge_type_Edge(self):
"""Test case: Check that edge is a Edge object
"""
g = Graph()
with self.assertRaises(TypeError) as context:
g.addEdge(('A','B'))
