Skip replayed letter event

Author: stevebux

internal/datastore/src/__test__/letter-repository.test.ts

@@ -9,6 +9,7 @@ import {
 import { LetterRepository } from "../letter-repository";
 import { InsertLetter, Letter, UpdateLetter } from "../types";
 import { LogStream, createTestLogger } from "./logs";
+import { LetterAlreadyExistsError } from "../letter-already-exists-error";
 
 function createLetter(
   supplierId: string,
@@ -149,9 +150,7 @@ describe("LetterRepository", () => {
     await letterRepository.putLetter(createLetter("supplier1", "letter1"));
     await expect(
       letterRepository.putLetter(createLetter("supplier1", "letter1")),
-    ).rejects.toThrow(
-      "Letter with id letter1 already exists for supplier supplier1",
-    );
+    ).rejects.toThrow(LetterAlreadyExistsError);
   });
 
   test("rethrows errors from DynamoDB when creating a letter", async () => {

internal/datastore/src/letter-repository.ts

@@ -18,6 +18,7 @@ import {
   LetterSchemaBase,
   UpdateLetter,
 } from "./types";
+import { LetterAlreadyExistsError } from "./letter-already-exists-error";
 
 export type PagingOptions = Partial<{
   exclusiveStartKey: Record<string, any>;
@@ -62,9 +63,7 @@ export class LetterRepository {
         error instanceof Error &&
         error.name === "ConditionalCheckFailedException"
       ) {
-        throw new Error(
-          `Letter with id ${letter.id} already exists for supplier ${letter.supplierId}`,
-        );
+        throw new LetterAlreadyExistsError(letter.supplierId, letter.id);
       }
       throw error;
     }

lambdas/upsert-letter/jest.config.ts

@@ -9,6 +9,9 @@ export const baseJestConfig = {
       },
     ],
   },
+  transformIgnorePatterns: [
+    "node_modules/(?!(@nhsdigital/nhs-notify-event-schemas-supplier-config)/)",
+  ],
 
   // Automatically clear mock calls, instances, contexts and results before every test
   clearMocks: true,

lambdas/upsert-letter/src/handler/__tests__/upsert-handler.test.ts

@@ -1,6 +1,9 @@
 import { SQSEvent, SQSRecord } from "aws-lambda";
 import pino from "pino";
-import { LetterRepository } from "internal/datastore/src";
+import {
+  LetterAlreadyExistsError,
+  LetterRepository,
+} from "@internal/datastore";
 import { LetterRequestPreparedEventV2 } from "@nhsdigital/nhs-notify-event-schemas-letter-rendering";
 import { LetterRequestPreparedEvent } from "@nhsdigital/nhs-notify-event-schemas-letter-rendering-v1";
 import {
@@ -199,7 +202,11 @@ describe("createUpsertLetterHandler", () => {
       putLetter: jest.fn(),
       updateLetterStatus: jest.fn(),
     } as unknown as LetterRepository,
-    logger: { error: jest.fn(), info: jest.fn() } as unknown as pino.Logger,
+    logger: {
+      error: jest.fn(),
+      warn: jest.fn(),
+      info: jest.fn(),
+    } as unknown as pino.Logger,
     env: {
       LETTERS_TABLE_NAME: "LETTERS_TABLE_NAME",
       LETTER_TTL_HOURS: 12_960,
@@ -301,6 +308,31 @@ describe("createUpsertLetterHandler", () => {
     );
   });
 
+  it("does not treat a replayed insert as a failure", async () => {
+    const v1message = {
+      letterEvent: createPreparedV1Event(),
+      supplierSpec: {
+        supplierId: "supplier1",
+        specId: "spec1",
+        priority: 10,
+        billingId: "billing1",
+      },
+    };
+    const evt: SQSEvent = createSQSEvent([
+      createSqsRecord("msg2", JSON.stringify(v1message)),
+    ]);
+    (mockedDeps.letterRepo.putLetter as jest.Mock).mockRejectedValue(
+      new LetterAlreadyExistsError("supplier1", "letter1"),
+    );
+
+    const result = await createUpsertLetterHandler(mockedDeps)(
+      evt,
+      {} as any,
+      {} as any,
+    );
+    expect(result!.batchItemFailures).toEqual([]);
+  });
+
   test("unknown supplier has metric emitted with 'unknown' supplier dimension", async () => {
     const letterEvent = createSupplierStatusChangeEventWithoutSupplier();
 

lambdas/upsert-letter/src/handler/upsert-handler.ts

@@ -1,5 +1,9 @@
 import { SQSBatchItemFailure, SQSEvent, SQSHandler } from "aws-lambda";
-import { InsertLetter, UpdateLetter } from "@internal/datastore";
+import {
+  InsertLetter,
+  LetterAlreadyExistsError,
+  UpdateLetter,
+} from "@internal/datastore";
 import {
   $LetterRequestPreparedEvent,
   LetterRequestPreparedEvent,
@@ -69,14 +73,26 @@ function getOperationFromType(type: string): UpsertOperation {
           supplierSpec.priority,
           supplierSpec.billingId, // use billingId for now
         );
-        await deps.letterRepo.putLetter(letterToInsert);
+        try {
+          await deps.letterRepo.putLetter(letterToInsert);
 
-        deps.logger.info({
-          description: "Inserted letter",
-          eventId: preparedRequest.id,
-          letterId: letterToInsert.id,
-          supplierId: letterToInsert.supplierId,
-        });
+          deps.logger.info({
+            description: "Inserted letter",
+            eventId: preparedRequest.id,
+            letterId: letterToInsert.id,
+            supplierId: letterToInsert.supplierId,
+          });
+        } catch (error) {
+          if (error instanceof LetterAlreadyExistsError) {
+            deps.logger.warn({
+              description: "Letter already exists",
+              supplierId: letterToInsert.supplierId,
+              letterId: letterToInsert.id,
+            });
+          } else {
+            throw error;
+          }
+        }
       },
     };
   }