make choose cheapest relevant plan method public as it's called from outside the module

backend/categorisation/processor.py

@@ -26,12 +26,29 @@ def process_portfolio(
         if not property_plans:
             raise ValueError(f"No plans for property {uprn}")
 
-        cheapest_plan = _choose_cheapest_relevant_plan(
+        cheapest_plan = choose_cheapest_relevant_plan(
             property_plans, plan_priority_order
         )
         _update_default_flags(property_plans, cheapest_plan)
 
 
+def choose_cheapest_relevant_plan(
+    plans: List[Plan], plan_priority_order: Optional[List[int]] = []
+) -> Plan:
+    plans_to_consider: List[Plan] = [p for p in plans if p.is_compliant] or plans
+
+    def plan_cost(plan: Plan) -> float:
+        return (
+            plan.record.cost_of_works
+            if plan.record.cost_of_works is not None
+            else float("inf")
+        )
+
+    cheapest_plan = min(plans_to_consider, key=plan_cost)
+
+    return cheapest_plan
+
+
 def _load_plans_for_portfolio(portfolio_id: int) -> List[Plan]:
     plans: List[Plan] = []
 
@@ -68,23 +85,6 @@ def _group_plans_by_property(plans: List[Plan]) -> Dict[int, List[Plan]]:
     return grouped
 
 
-def _choose_cheapest_relevant_plan(
-    plans: List[Plan], plan_priority_order: Optional[List[int]] = []
-) -> Plan:
-    plans_to_consider: List[Plan] = [p for p in plans if p.is_compliant] or plans
-
-    def plan_cost(plan: Plan) -> float:
-        return (
-            plan.record.cost_of_works
-            if plan.record.cost_of_works is not None
-            else float("inf")
-        )
-
-    cheapest_plan = min(plans_to_consider, key=plan_cost)
-
-    return cheapest_plan
-
-
 def _update_default_flags(plans: List[Plan], cheapest_plan: Plan) -> None:
     plans_to_update: List[Plan] = []
 

backend/categorisation/tests/test_prioritised_plan_selected.py

@@ -7,7 +7,7 @@ from backend.app.domain.classes.scenario import Scenario
 from backend.app.domain.records.plan_record import PlanRecord
 from backend.app.domain.records.scenario_record import ScenarioRecord
 from backend.app.db.models.portfolio import Epc, PortfolioGoal
-from backend.categorisation.processor import _choose_cheapest_relevant_plan
+from backend.categorisation.processor import choose_cheapest_relevant_plan
 
 
 @pytest.fixture
@@ -79,7 +79,7 @@ def test_prioritised_plan_selected(created_at_datetime: datetime) -> None:
     expected_default_plan_id = 2
 
     # act
-    actual_default_plan = _choose_cheapest_relevant_plan(
+    actual_default_plan = choose_cheapest_relevant_plan(
         plans=[epc_c_plan, minor_works_plan],
         plan_priority_order=plan_priority_order,
     )