Address review comments

Author: stevebux

lambdas/update-letter-queue/src/__tests__/update-letter-queue.test.ts

@@ -188,7 +188,7 @@ describe("update-letter-queue Lambda", () => {
       const oldLetter2 = generateLetter("PENDING", { id: "2" });
       const newLetter1 = generateLetter("ACCEPTED", { id: "1" });
       const newLetter2 = generateLetter("ACCEPTED", { id: "2" });
-      (mockedDeps.letterQueueRepository.putLetter as jest.Mock)
+      (mockedDeps.letterQueueRepository.deleteLetter as jest.Mock)
         .mockRejectedValueOnce(new LetterDoesNotExistError("supplier1", "1"))
         .mockResolvedValueOnce({});
 
@@ -328,7 +328,7 @@ describe("update-letter-queue Lambda", () => {
     });
 
     // eslint-disable-next-line jest/expect-expect
-    it("counts a replayed deleted as zero", async () => {
+    it("counts a replayed delete as zero", async () => {
       const handler = createHandler(mockedDeps);
       const oldLetter1 = generateLetter("PENDING", { id: "1" });
       const oldLetter2 = generateLetter("PENDING", { id: "2" });
@@ -423,7 +423,7 @@ function mapToImage(oldLetter: Letter) {
 function assertQueueDeltaMetricLogged(supplierId: string, delta: number) {
   expect(mockedDeps.logger.info).toHaveBeenCalledWith(
     expect.objectContaining({
-      supplierId,
+      supplier: supplierId,
       _aws: expect.objectContaining({
         CloudWatchMetrics: expect.arrayContaining([
           expect.objectContaining({

lambdas/update-letter-queue/src/update-letter-queue.ts

@@ -33,15 +33,15 @@ export default function createHandler(deps: Deps): Handler<KinesisStreamEvent> {
       const ddbRecord = extractPayload(record, deps);
 
       try {
-        const letter = extractNewOrUpdatedLetter(ddbRecord);
-
         if (isNewPendingLetter(ddbRecord)) {
-          const added = await addPendingLetterToQueue(letter!, deps);
-          updateDeltas(deltasBySupplierId, letter!.supplierId, added);
+          const letter = extractNewOrUpdatedLetter(ddbRecord);
+          const added = await addPendingLetterToQueue(letter, deps);
+          updateDeltas(deltasBySupplierId, letter.supplierId, added);
           successCount += added;
         } else if (isNoLongerPending(ddbRecord)) {
-          const deleted = await deletePendingLetterFromQueue(letter!, deps);
-          updateDeltas(deltasBySupplierId, letter!.supplierId, -deleted);
+          const letter = extractNewOrUpdatedLetter(ddbRecord);
+          const deleted = await deletePendingLetterFromQueue(letter, deps);
+          updateDeltas(deltasBySupplierId, letter.supplierId, -deleted);
           successCount += deleted;
         }
       } catch (error) {
@@ -179,9 +179,9 @@ function extractPayload(
   }
 }
 
-function extractNewOrUpdatedLetter(record: DynamoDBRecord): Letter | undefined {
+function extractNewOrUpdatedLetter(record: DynamoDBRecord): Letter {
   const newImage = record.dynamodb?.NewImage;
-  return newImage ? LetterSchema.parse(unmarshall(newImage as any)) : undefined;
+  return LetterSchema.parse(unmarshall(newImage as any));
 }
 
 function mapLetterToPendingLetter(letter: Letter): InsertPendingLetter {
@@ -196,7 +196,7 @@ function mapLetterToPendingLetter(letter: Letter): InsertPendingLetter {
 function buildMetric(supplierId: string, delta: number) {
   return buildEMFObject(
     "update-letter-queue",
-    { supplierId },
+    { supplier: supplierId },
     {
       key: "QueueDelta",
       value: delta,