[ILibraryView] child_order shouldn't leak graphlib.CycleErrror

masque/test/test_library.py

@@ -293,6 +293,26 @@ def test_library_subtree() -> None:
     assert "c" not in sub
 
 
+def test_library_child_order_cycle_raises_library_error() -> None:
+    lib = Library()
+    lib["a"] = Pattern()
+    lib["a"].ref("b")
+    lib["b"] = Pattern()
+    lib["b"].ref("a")
+
+    with pytest.raises(LibraryError, match="Cycle found while building child order"):
+        lib.child_order()
+
+
+def test_library_find_refs_global_cycle_raises_library_error() -> None:
+    lib = Library()
+    lib["a"] = Pattern()
+    lib["a"].ref("a")
+
+    with pytest.raises(LibraryError, match="Cycle found while building child order"):
+        lib.find_refs_global("a")
+
+
 def test_library_get_name() -> None:
     lib = Library()
     lib["cell"] = Pattern()