fix: add missing test_parity_prefactor (#2)

tests/unit/test_parity_prefactor.py

@@ -0,0 +1,82 @@
+from typing import NamedTuple, Tuple
+
+import pytest
+
+from qrules.default_settings import InteractionTypes
+from qrules.transition import StateTransitionManager
+
+
+class Input(NamedTuple):
+    initial_state: list
+    final_state: list
+    intermediate_states: list
+    final_state_grouping: list
+
+
+@pytest.mark.parametrize(
+    "test_input, ingoing_state, related_component_names, relative_parity_prefactor",
+    [
+        (
+            Input(
+                [("J/psi(1S)", [1])],
+                [("gamma", [-1, 1]), ("pi0", [0]), ("pi0", [0])],
+                ["f(0)(980)"],
+                ["pi0", "pi0"],
+            ),
+            "J/psi(1S)",
+            (
+                "J/psi(1S)_1_to_f(0)(980)_0+gamma_1;f(0)(980)_0_to_pi0_0+pi0_0;",
+                "J/psi(1S)_1_to_f(0)(980)_0+gamma_-1;f(0)(980)_0_to_pi0_0+pi0_0;",
+            ),
+            1.0,
+        ),
+        (
+            Input(
+                [("J/psi(1S)", [1])],
+                [("pi0", [0]), ("pi+", [0]), ("pi-", [0])],
+                ["rho(770)"],
+                ["pi+", "pi-"],
+            ),
+            "J/psi(1S)",
+            (
+                "J/psi(1S)_1_to_pi0_0+rho(770)0_1;rho(770)0_1_to_pi+_0+pi-_0;",
+                "J/psi(1S)_1_to_pi0_0+rho(770)0_-1;rho(770)0_-1_to_pi+_0+pi-_0;",
+            ),
+            -1.0,
+        ),
+    ],
+)
+def test_parity_prefactor(
+    test_input: Input,
+    ingoing_state: str,
+    related_component_names: Tuple[str, str],
+    relative_parity_prefactor: float,
+) -> None:
+    # pylint: disable=unused-argument
+    stm = StateTransitionManager(
+        test_input.initial_state,
+        test_input.final_state,
+        allowed_intermediate_particles=test_input.intermediate_states,
+        number_of_threads=1,
+    )
+    stm.add_final_state_grouping(test_input.final_state_grouping)
+    stm.set_allowed_interaction_types([InteractionTypes.EM])
+    problem_sets = stm.create_problem_sets()
+
+    result = stm.find_solutions(problem_sets)
+
+    for solution in result.transitions:
+        in_edge = [
+            edge_id
+            for edge_id in solution.topology.edges
+            if solution.get_edge_props(edge_id)[0].name == ingoing_state
+        ]
+        assert len(in_edge) == 1
+        node_id = solution.topology.edges[in_edge[0]].ending_node_id
+
+        assert isinstance(node_id, int)
+
+        assert (
+            relative_parity_prefactor
+            == solution.get_node_props(node_id).parity_prefactor
+        )