def test_transitive_reduction_no_reduction():
dag = DAG()
dag.from_dict({'a': ['b', 'c'], 'b': ['d'], 'c': ['d'], 'd': []})
dag.transitive_reduction()
assert dag.graph == {
'a': set(['b', 'c']),
'b': set('d'),
'c': set('d'),
'd': set()
}
def test_transitive_reduction_no_reduction():
dag = DAG()
dag.from_dict({'a': ['b', 'c'],
'b': ['d'],
'c': ['d'],
'd': []})
dag.transitive_reduction()
assert dag.graph == {'a': set(['b', 'c']),
'b': set('d'),
'c': set('d'),
'd': set()}
def test_transitive_deep_reduction():
dag = DAG()
# https://en.wikipedia.org/wiki/Transitive_reduction#/media/File:Tred-G.svg
dag.from_dict({
'a': ['b', 'd'],
'b': ['c'],
'c': ['d'],
'd': [],
})
dag.transitive_reduction()
# https://en.wikipedia.org/wiki/Transitive_reduction#/media/File:Tred-Gprime.svg
assert dag.graph == {'a': set('b'),
'b': set('c'),
'c': set('d'),
'd': set()}