Tuple unpacking bug fix in cut finder. (#591)

* tuple unpacking bug fix, edit tests and type hints accordingly.

* remove extraneous type hint

circuit_knitting/cutting/cut_finding/cutting_actions.py

@@ -417,7 +417,7 @@ def next_state_primitive(
         new_state.bell_pairs.append((r2, rnew_2))
         new_state.gamma_UB *= 16
 
-        new_state.add_action(self, gate_spec, ((1, w1, rnew_1), (2, w2, rnew_2)))
+        new_state.add_action(self, gate_spec, (1, w1, rnew_1), (2, w2, rnew_2))
 
         return [new_state]
 

circuit_knitting/cutting/cut_finding/disjoint_subcircuits_state.py

@@ -37,7 +37,7 @@ class Action(NamedTuple):
 
     action: DisjointSearchAction
     gate_spec: GateSpec
-    args: list
+    args: list | tuple
 
 
 class GateCutLocation(NamedTuple):
@@ -430,12 +430,12 @@ def add_action(
         self,
         action_obj: DisjointSearchAction,
         gate_spec: GateSpec,
-        args: tuple | None = None,
+        *args: tuple,
     ) -> None:
         """Append the specified action to the list of search-space actions that have been performed."""
         if action_obj.get_name() is not None:
             self.actions = cast(list, self.actions)
-            self.actions.append(Action(action_obj, gate_spec, [args]))
+            self.actions.append(Action(action_obj, gate_spec, args))
 
     def get_search_level(self) -> int:
         """Return the search level."""

test/cutting/cut_finding/test_best_first_search.py

@@ -114,23 +114,23 @@ def test_best_first_search(test_circuit: SimpleGateList):
                 gate=CircuitElement(name="cx", params=[], qubits=[3, 4], gamma=3),
                 cut_constraints=None,
             ),
-            [((1, 3), (2, 4))],
+            (((1, 3), (2, 4)),),
         ),
         (
             GateSpec(
                 instruction_id=13,
                 gate=CircuitElement(name="cx", params=[], qubits=[3, 5], gamma=3),
                 cut_constraints=None,
             ),
-            [((1, 3), (2, 5))],
+            (((1, 3), (2, 5)),),
         ),
         (
             GateSpec(
                 instruction_id=14,
                 gate=CircuitElement(name="cx", params=[], qubits=[3, 6], gamma=3),
                 cut_constraints=None,
             ),
-            [((1, 3), (2, 6))],
+            (((1, 3), (2, 6)),),
         ),
     ]