make stats idempotent too

Author: nhsd-david-wass

lambdas/supplier-allocator/src/handler/allocate-handler.ts

@@ -32,7 +32,6 @@ import {
 
 import { Deps } from "../config/deps";
 import { PreparedEventSchema, PreparedEvents, SupplierDetails } from "./types";
-import { domain } from "zod/v4/core/regexes.cjs";
 
 const idempotencyConfig = new IdempotencyConfig({
   eventKeyJmesPath: "id",
@@ -270,9 +269,6 @@ async function saveAllocations(
 type SupplierAllocationResult = {
   supplier: string;
   priority: string;
-  perAllocationSuccess: AllocationMetrics;
-  perAllocationFailure: AllocationMetrics;
-  volumeGroupAllocations: VolumeGroupAllocation;
 };
 
 async function processSupplierAllocation(
@@ -342,22 +338,42 @@ async function processSupplierAllocation(
   return {
     supplier,
     priority,
-    perAllocationSuccess,
-    perAllocationFailure,
-    volumeGroupAllocations,
   };
 }
 
 export default function createSupplierAllocatorHandler(deps: Deps): SQSHandler {
-  const getSupplierIdempotently = makeIdempotent(processSupplierAllocation, {
-    persistenceStore: deps.idempotencyLayer,
-    config: idempotencyConfig,
-  });
+  const getSupplierIdempotently = (
+    perAllocationSuccess: AllocationMetrics,
+    perAllocationFailure: AllocationMetrics,
+    volumeGroupAllocations: VolumeGroupAllocation,
+  ) => {
+    return makeIdempotent(
+      (letterEvent: PreparedEvents, depsInner: Deps) =>
+        processSupplierAllocation(
+          letterEvent,
+          depsInner,
+          perAllocationSuccess,
+          perAllocationFailure,
+          volumeGroupAllocations,
+        ),
+      {
+        persistenceStore: deps.idempotencyLayer,
+        config: idempotencyConfig,
+      },
+    );
+  };
   return async (event: SQSEvent, context: Context) => {
     const batchItemFailures: SQSBatchItemFailure[] = [];
-    let perAllocationSuccess: AllocationMetrics = new Map();
-    let perAllocationFailure: AllocationMetrics = new Map();
-    let volumeGroupAllocations: VolumeGroupAllocation = new Map();
+    const perAllocationSuccess: AllocationMetrics = new Map();
+    const perAllocationFailure: AllocationMetrics = new Map();
+    const volumeGroupAllocations: VolumeGroupAllocation = new Map();
+
+    // create an idempotent function bound to this handler's batchItemFailures
+    const boundGetSupplierIdempotently = getSupplierIdempotently(
+      perAllocationSuccess,
+      perAllocationFailure,
+      volumeGroupAllocations,
+    );
 
     const tasks = event.Records.map(async (record) => {
       let supplier = "unknown";
@@ -376,29 +392,17 @@ export default function createSupplierAllocatorHandler(deps: Deps): SQSHandler {
         idempotencyConfig.registerLambdaContext(context);
 
         const supplierAllocationResult: SupplierAllocationResult =
-          await getSupplierIdempotently(
-            letterEvent,
-            deps,
-            perAllocationSuccess,
-            perAllocationFailure,
-            volumeGroupAllocations,
-          );
+          await boundGetSupplierIdempotently(letterEvent, deps);
         deps.logger.info({
           description: "Completed supplier allocation for letter event",
           eventId: letterEvent.id,
           domainId: letterEvent.data.domainId,
           letterVariantId: letterEvent.data.letterVariantId,
           supplier: supplierAllocationResult.supplier,
           priority: supplierAllocationResult.priority,
-          updatedVolumeGroupAllocations:
-            supplierAllocationResult.volumeGroupAllocations,
         });
         supplier = supplierAllocationResult.supplier;
         priority = supplierAllocationResult.priority;
-        perAllocationSuccess = supplierAllocationResult.perAllocationSuccess;
-        perAllocationFailure = supplierAllocationResult.perAllocationFailure;
-        volumeGroupAllocations =
-          supplierAllocationResult.volumeGroupAllocations;
         deps.logger.info({
           description:
             "Completed processing supplier allocation for letter event",