def test_remove_vertex():
trek = Space()
captain = trek.add_vertex('Captain')
kirk = trek.add_vertex(name='James T. Kirk')
pike = trek.add_vertex(name='Christopher Pike')
edges = []
for person in [kirk, pike]:
edges.append(trek.add_edge(person, captain, 'has_rank'))
trek.remove_vertex(captain.id)
for edge in edges:
with pytest.raises(MissingEdge):
trek.edge_by_id(edge.id)
assert trek.vertex_by_id(kirk.id) == kirk
assert trek.vertex_by_id(pike.id) == pike
def test_find_vertex_by_id():
trek = Space()
kirk = trek.add_vertex(name='James T. Kirk')
assert trek.vertex_by_id(kirk.id) == kirk