def test_directed_vertex_not_part_of_edge(self):
""" A directed vertex should not be able add an edge which doesn't have
it as a vertex """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
v2 = DirectedVertex(val='v2')
e12 = DirectedEdge((v1, v2))
with self.assertRaises(ValueError):
v0.add_edge(e12)
def test_directed_vertex_add_edge(self):
""" Add an edge to a directed vertex """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
v2 = DirectedVertex(val='v2')
e01 = DirectedEdge((v0, v1))
e10 = DirectedEdge((v1, v0))
e02 = DirectedEdge((v0, v2))
v0.add_edge(e01)
self.assertTrue(e01 in v0)
self.assertFalse(e10 in v0)
self.assertFalse(e02 in v0)
def test_directed_vertex_outs_and_ins_and_degrees(self):
""" Get directed vertices' outs, ins, out_degree, and in_degree
properties """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
v2 = DirectedVertex(val='v2')
e00 = DirectedEdge((v0, v0))
e01 = DirectedEdge((v0, v1))
e02 = DirectedEdge((v0, v2))
e10 = DirectedEdge((v1, v0))
v0.add_edge(e00)
v0.add_edge(e01)
v0.add_edge(e02)
v0.add_edge(e10)
self.assertEqual(set(v0.outs), set([v0, v1, v2]))
self.assertEqual(set(v0.ins), set([v0, v1]))
self.assertEqual(v0.out_degree, 3)
self.assertEqual(v0.in_degree, 2)
self.assertEqual(v0.degree, 5)
def test_directed_vertex_remove_edge(self):
""" Remove an edge from a directed vertex """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
v2 = DirectedVertex(val='v2')
e01 = DirectedEdge((v0, v1))
e10 = DirectedEdge((v1, v0))
e02 = DirectedEdge((v0, v2))
v0.add_edge(e01)
v0.add_edge(e10)
v0.add_edge(e02)
v0.remove_edge(e01)
self.assertFalse(e01 in v0)
self.assertTrue(e10 in v0)
self.assertTrue(e02 in v0)
v0.remove_edge(e02)
self.assertFalse(e01 in v0)
self.assertTrue(e10 in v0)
self.assertFalse(e02 in v0)
def test_directed_vertex_edges(self):
""" Get a directed vertex's edges property """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
v2 = DirectedVertex(val='v2')
e00 = DirectedEdge((v0, v0))
e01 = DirectedEdge((v0, v1))
e20 = DirectedEdge((v2, v0))
v0.add_edge(e00)
v0.add_edge(e01)
v1.add_edge(e01)
v0.add_edge(e20)
v2.add_edge(e20)
self.assertEqual(set(v0.edges), set([e00, e01, e20]))
self.assertEqual(set(v1.edges), set([e01]))
self.assertEqual(set(v2.edges), set([e20]))
with self.assertRaises(AttributeError):
v0.edges = set()
def test_directed_vertex_already_has_edge(self):
""" A directed vertex should not be able to add an edge that it already
has """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
e01 = DirectedEdge((v0, v1))
e10 = DirectedEdge((v1, v0))
v0.add_edge(e01)
with self.assertRaises(ValueError):
v0.add_edge(e01)
try:
v1.add_edge(e01)
except ValueError:
self.fail("Adding the edge (v0, v1) to v0 should not stop the edge "
"(v0, v1) from being added to v1.")
try:
v0.add_edge(e10)
except ValueError:
self.fail("There should be no exception because (v1 -> v0) is a "
"different edge than (v0 -> v1) for a directed vertex.")
