type modernization

tests/test_dag.py

@@ -3,11 +3,17 @@ from __future__ import annotations
 import pytest
 
 from daglib.dag import DAG
+from daglib.operations import all_nodes, transitive_closure
+from daglib.typing import DAGType, dictset
 
 
 class TestDAGInit:
     """Test DAG initialization."""
 
+    def test_generic_alias_parameters(self) -> None:
+        assert len(dictset.__type_params__) == 1
+        assert len(DAGType.__type_params__) == 1
+
     def test_init_empty(self) -> None:
         g = DAG()
         assert len(g) == 0
@@ -281,6 +287,20 @@ class TestDAGCallbacks:
 class TestDAGComplexScenarios:
     """Test complex usage patterns."""
 
+    def test_typed_traversal_and_subclass_returns(self) -> None:
+        class IntDAG(DAG[int]):
+            pass
+
+        graph = IntDAG()
+        graph.add_edge(1, 2)
+        graph.add_edge(2, 3)
+        assert all_nodes(graph) == {1, 2, 3}
+        assert transitive_closure(graph, 1) == {1, 2, 3}
+        assert isinstance(graph.reverse, IntDAG)
+        assert isinstance(graph.subgraph(1), IntDAG)
+        graph.remove_edge(1, 2)
+        assert 2 not in graph[1]
+
     def test_chain_graph(self) -> None:
         g = DAG[str]()
         g["foo"] = {"bar"}