diff env/lib/python3.9/site-packages/networkx/algorithms/tests/test_bridges.py @ 0:4f3585e2f14b draft default tip

"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.9/site-packages/networkx/algorithms/tests/test_bridges.py	Mon Mar 22 18:12:50 2021 +0000
@@ -0,0 +1,74 @@
+"""Unit tests for bridge-finding algorithms."""
+
+import networkx as nx
+
+
+class TestBridges:
+    """Unit tests for the bridge-finding function."""
+
+    def test_single_bridge(self):
+        edges = [
+            # DFS tree edges.
+            (1, 2),
+            (2, 3),
+            (3, 4),
+            (3, 5),
+            (5, 6),
+            (6, 7),
+            (7, 8),
+            (5, 9),
+            (9, 10),
+            # Nontree edges.
+            (1, 3),
+            (1, 4),
+            (2, 5),
+            (5, 10),
+            (6, 8),
+        ]
+        G = nx.Graph(edges)
+        source = 1
+        bridges = list(nx.bridges(G, source))
+        assert bridges == [(5, 6)]
+
+    def test_barbell_graph(self):
+        # The (3, 0) barbell graph has two triangles joined by a single edge.
+        G = nx.barbell_graph(3, 0)
+        source = 0
+        bridges = list(nx.bridges(G, source))
+        assert bridges == [(2, 3)]
+
+
+class TestLocalBridges:
+    """Unit tests for the local_bridge function."""
+
+    @classmethod
+    def setup_class(cls):
+        cls.BB = nx.barbell_graph(4, 0)
+        cls.square = nx.cycle_graph(4)
+        cls.tri = nx.cycle_graph(3)
+
+    def test_nospan(self):
+        expected = {(3, 4), (4, 3)}
+        assert next(nx.local_bridges(self.BB, with_span=False)) in expected
+        assert set(nx.local_bridges(self.square, with_span=False)) == self.square.edges
+        assert list(nx.local_bridges(self.tri, with_span=False)) == []
+
+    def test_no_weight(self):
+        inf = float("inf")
+        expected = {(3, 4, inf), (4, 3, inf)}
+        assert next(nx.local_bridges(self.BB)) in expected
+        expected = {(u, v, 3) for u, v, in self.square.edges}
+        assert set(nx.local_bridges(self.square)) == expected
+        assert list(nx.local_bridges(self.tri)) == []
+
+    def test_weight(self):
+        inf = float("inf")
+        G = self.square.copy()
+
+        G.edges[1, 2]["weight"] = 2
+        expected = {(u, v, 5 - wt) for u, v, wt in G.edges(data="weight", default=1)}
+        assert set(nx.local_bridges(G, weight="weight")) == expected
+
+        expected = {(u, v, 6) for u, v in G.edges}
+        lb = nx.local_bridges(G, weight=lambda u, v, d: 2)
+        assert set(lb) == expected