chore: import upstream snapshot with attribution

2026-07-13 12:36:30 +08:00
commit 55ab4e4a73
473 changed files with 72932 additions and 0 deletions
@@ -0,0 +1,82 @@
+import unittest
+
+import easygraph as eg
+
+from easygraph import is_weakly_connected
+from easygraph import number_weakly_connected_components
+from easygraph import weakly_connected_components
+from easygraph.utils.exception import EasyGraphNotImplemented
+from easygraph.utils.exception import EasyGraphPointlessConcept
+
+
+class Test_weakly_connected(unittest.TestCase):
+    def test_empty_graph(self):
+        G = eg.DiGraph()
+        with self.assertRaises(EasyGraphPointlessConcept):
+            is_weakly_connected(G)
+        self.assertEqual(number_weakly_connected_components(G), 0)
+        self.assertEqual(list(weakly_connected_components(G)), [])
+
+    def test_single_node(self):
+        G = eg.DiGraph()
+        G.add_node(1)
+        self.assertTrue(is_weakly_connected(G))
+        self.assertEqual(number_weakly_connected_components(G), 1)
+        self.assertEqual(list(weakly_connected_components(G)), [{1}])
+
+    def test_connected_graph(self):
+        G = eg.DiGraph([(1, 2), (2, 3), (3, 4)])
+        self.assertTrue(is_weakly_connected(G))
+        self.assertEqual(number_weakly_connected_components(G), 1)
+        self.assertEqual(list(weakly_connected_components(G)), [{1, 2, 3, 4}])
+
+    def test_disconnected_graph(self):
+        G = eg.DiGraph([(1, 2), (3, 4)])
+        self.assertFalse(is_weakly_connected(G))
+        wcc = list(weakly_connected_components(G))
+        self.assertEqual(len(wcc), 2)
+        self.assertIn({1, 2}, wcc)
+        self.assertIn({3, 4}, wcc)
+
+    def test_self_loops(self):
+        G = eg.DiGraph([(1, 1), (2, 2)])
+        wcc = list(weakly_connected_components(G))
+        self.assertEqual(len(wcc), 2)
+        self.assertIn({1}, wcc)
+        self.assertIn({2}, wcc)
+        self.assertFalse(is_weakly_connected(G))
+
+    def test_multiple_components(self):
+        G = eg.DiGraph([(1, 2), (3, 4), (5, 6), (6, 5)])
+        wcc = list(weakly_connected_components(G))
+        self.assertEqual(number_weakly_connected_components(G), 3)
+        self.assertIn({1, 2}, wcc)
+        self.assertIn({3, 4}, wcc)
+        self.assertIn({5, 6}, wcc)
+
+    def test_unconnected_nodes(self):
+        G = eg.DiGraph([(1, 2), (3, 4)])
+        G.add_node(99)  # isolated node
+        wcc = list(weakly_connected_components(G))
+        self.assertEqual(len(wcc), 3)
+        self.assertIn({99}, wcc)
+
+    def test_is_weakly_connected_after_adding_edge(self):
+        G = eg.DiGraph([(0, 1), (2, 1)])
+        G.add_node(3)
+        self.assertFalse(is_weakly_connected(G))
+        G.add_edge(2, 3)
+        self.assertTrue(is_weakly_connected(G))
+
+    def test_undirected_raises(self):
+        G = eg.Graph([(1, 2), (2, 3)])
+        with self.assertRaises(EasyGraphNotImplemented):
+            is_weakly_connected(G)
+        with self.assertRaises(EasyGraphNotImplemented):
+            number_weakly_connected_components(G)
+        with self.assertRaises(EasyGraphNotImplemented):
+            list(weakly_connected_components(G))
+
+
+if __name__ == "__main__":
+    unittest.main()