def test_topological_sort_DAG():
ordering = basic.topological_sort({
"A": [],
"B": [],
"C": ["A", "B"],
"D": ["A", "B"],
"E": ["A", "C"],
"F": ["B", "D"],
"G": ["A", "E"],
"H": ["B", "F"]
})
assert set(ordering[0:2]) == {"A", "B"}
assert is_before("A", "C", ordering)
assert is_before("B", "C", ordering)
assert is_before("A", "D", ordering)
assert is_before("B", "D", ordering)
assert is_before("A", "E", ordering)
assert is_before("C", "E", ordering)
assert is_before("B", "F", ordering)
assert is_before("D", "F", ordering)
assert is_before("A", "G", ordering)
assert is_before("E", "G", ordering)
assert is_before("B", "H", ordering)
assert is_before("F", "H", ordering)
def test_topological_sort_circular_3():
with pytest.raises(basic.GraphException) as e:
ordering = basic.topological_sort({
"D": ["C", "B"],
"C": ["A"],
"B": ["A"],
"A": ["D"]
})
assert str(e.value) == "Circular dependency detected in graph"
def test_topological_sort_diamond_1():
ordering = basic.topological_sort({
"D": ["C", "B"],
"C": ["A"],
"B": ["A"],
"A": []
})
assert ordering[0] == "A"
assert set(ordering[1:3]) == {"B", "C"}
assert ordering[-1] == "D"
def test_topological_sort_one_dependency():
ordering = basic.topological_sort({"B": ["A"]})
assert ordering == ["A", "B"]
def test_topological_sort_empty():
ordering = basic.topological_sort({})
assert len(ordering) == 0