def test_get_vertex_ids_graph_with_one_vertex():
"""Test whether method DirectedGraph.get_vertex_ids() works correctly for graph with vertex."""
g = DirectedGraph()
v0 = g.add_vertex(vertex_props=None)
list_ids = g.get_vertex_ids()
assert len(list_ids) == 1
assert v0.id in list_ids
def test_get_vertex_ids():
g = DirectedGraph()
v0 = g.add_vertex(vertex_props=None)
v1 = g.add_vertex(vertex_props=None)
list_ids = g.get_vertex_ids()
assert len(list_ids) == 2
assert v0.id in list_ids
assert v1.id in list_ids
def test_get_vertex_ids():
"""Test whether method DirectedGraph.get_vertex_ids() works correctly."""
g = DirectedGraph()
v0 = g.add_vertex(vertex_props=None)
v1 = g.add_vertex(vertex_props=None)
list_ids = g.get_vertex_ids()
assert len(list_ids) == 2
assert v0.id in list_ids
assert v1.id in list_ids
def test_get_vertex_ids_empty_graph():
"""Test whether method DirectedGraph.get_vertex_ids() works correctly for empty graph."""
g = DirectedGraph()
list_ids = g.get_vertex_ids()
assert not list_ids
