def test_add_edge_between_nonexistent_vertices():
"""Test whether method DirectedGraph.add_edge() works correctly."""
g = DirectedGraph()
v0 = Vertex(0, {})
v1 = Vertex(1, {})
# neither vertex are put into the directed graph, so it is impossible
# to add an edge to connect them. ATM the exception thrown by the
# add_edge method is not very specific, it might need to be improved.
with pytest.raises(Exception):
g.add_edge(from_id=v0.id, to_id=v1.id)
def test_get_unvisited_neighbor__none_available():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v)
end_v.visited = True
assert start_v.get_unvisited_neighbor() is None
def test_has_neighbor():
start_v = Vertex('1')
assert start_v.has_neighbor() is False
# Add a neighbor
start_v.connect(end_vertex=Vertex('2'))
assert start_v.has_neighbor()
def test_has_and_set_predecessor():
end_v = Vertex('2')
assert end_v.has_predecessor() is False
start_v = Vertex('1') # The predecessor
end_v.set_predecessor(start_v)
assert end_v.has_predecessor()
def test_add_neigbor():
"""Check the methods add_neighbor and get_neighbours."""
v = Vertex(1, {})
assert not v.get_neighbours()
v2 = Vertex(2, {})
v.add_neighbor(v2, 100)
assert v2 in v.get_neighbours()
def test_get_weight():
"""Check the method get_weight."""
v = Vertex(1, {})
v2 = Vertex(2, {})
v.add_neighbor(v2, 100)
assert v.get_weight(v2) == 100
# v3 is not in any relatioship with v
with pytest.raises(Exception):
v3 = Vertex(3, {})
assert v.get_weight(v3) == 100
def test_find_common_reachable_vertex_empty_graph():
"""Test if method DirectedGraph.find_common_reachable_vertices() works correctly."""
list_vertices = DirectedGraph.find_common_reachable_vertices(input_vertices=None)
assert list_vertices is None
list_vertices = DirectedGraph.find_common_reachable_vertices(input_vertices=[])
assert list_vertices is None
v0 = Vertex(0, {})
list_vertices = DirectedGraph.find_common_reachable_vertices(input_vertices=[v0])
assert list_vertices is not None
assert list_vertices[0] == v0
def test_get_unvisited_neighbor__valid_result():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v)
result = start_v.get_unvisited_neighbor()
assert result == end_v
def test_string_representation_4():
"""Check special method __str__ for vertices with properies."""
v = Vertex(1, {})
v.set_prop_value("name", "value")
s = str(v)
assert s == """
Vertex: 1
Neighbours: []
Properties: {'name': 'value'}
"""
v = Vertex(2, {})
v.set_prop_value("other", "XXX")
s = str(v)
assert s == """
def test_properties():
"""Check methods get_prop_value and set_prop_value."""
v = Vertex(1, {})
with pytest.raises(Exception):
assert v.get_prop_value("something") is None
v.set_prop_value("name", "value")
assert v.get_prop_value("name") == "value"
with pytest.raises(Exception):
# this statement still should raise an exception
assert v.get_prop_value("something") is None
def test_string_representation_5():
"""Check special method __str__ for vertices with neighbours."""
v = Vertex(100, {})
v2 = Vertex(2, {})
v.add_neighbor(v2, 200)
s = str(v)
assert s == """
Vertex: 100
Neighbours: [2]
Properties: {}
"""
v3 = Vertex(3, {})
v.add_neighbor(v3, 300)
s = str(v)
assert s == """
Vertex: 100
Neighbours: [2, 3]
Properties: {}
""" or s == """
def test_connect__edge_vertext():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v, edge_weight=5)
edge = start_v.edgelist[0]
assert edge.vertex == end_v
def connected_vertex():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v, edge_weight=5) # Add edge
return start_v
def test_connect__creates_Edge_in_edgelist():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v, edge_weight=5)
assert len(start_v.edgelist) == 1
def test_connect__default_weight_is_0():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v)
assert start_v.edgelist[0].weight == 0
def test_connect__success_returns_True():
start_v = Vertex('1')
end_v = Vertex('2')
assert start_v.connect(end_vertex=end_v, edge_weight=5)
def test_init__predecessor_is_None():
v = Vertex('vertex')
assert v.predecessor is None
def test_init__cost_is_0():
v = Vertex('vertex')
assert v.cost == 0
def test_init__prev_vertex_is_None():
v = Vertex('vertex')
assert v.prev_vertex is None
def test_connect__dupe_edge_returns_False():
start_v = Vertex('1')
end_v = Vertex('2')
start_v.connect(end_vertex=end_v, edge_weight=5) # Add edge
result = start_v.connect(end_vertex=end_v, edge_weight=5) # Add again
assert result is False
def test_connect__same_vertices_returns_False():
start_v = Vertex('1')
assert start_v.connect(end_vertex=start_v, edge_weight=5) is False
def test_get_cost():
end_v = Vertex('2')
assert end_v.cost == 0
def test_string_representation_2():
"""Check special method __str__ for simple vertex."""
v = Vertex(100, {})
s = str(v)
assert s == """
def test_init__label():
v = Vertex('vertex')
assert v.label == 'vertex'
def test_has_predecessor__DNE_returns_False():
end_v = Vertex('2')
assert end_v.has_predecessor() is False
def test_get_predecessor():
end_v = Vertex('2')
start_v = Vertex('1') # The predecessor
end_v.set_predecessor(start_v)
assert end_v.get_predecessor() == start_v
def test_connect__same_vertices__no_edge_added():
start_v = Vertex('1')
start_v.connect(end_vertex=start_v, edge_weight=5)
assert len(start_v.edgelist) == 0
def test_init__visited_is_False():
v = Vertex('vertex')
assert v.visited is False
def test_set_cost():
end_v = Vertex('2')
end_v.set_cost(20)
assert end_v.cost == 20
def test_init__edgelist_is_empty():
v = Vertex('vertex')
assert v.edgelist == []
