CCM-11603: Get letter data

lambdas/api-handler/src/handlers/get-letter-data.ts

@@ -1,5 +1,5 @@
 import { APIGatewayProxyHandler } from "aws-lambda";
-import { assertNotEmpty, lowerCaseKeys } from "../utils/validation";
+import { assertNotEmpty, validateCommonHeaders } from "../utils/validation";
 import { ApiErrorDetail } from '../contracts/errors';
 import { mapErrorToResponse } from "../mappers/error-mapper";
 import { ValidationError } from "../errors";
@@ -11,28 +11,26 @@ export function createGetLetterDataHandler(deps: Deps): APIGatewayProxyHandler {
 
   return async (event) => {
 
-    let correlationId: string | undefined;
+    const commonHeadersResult = validateCommonHeaders(event.headers, deps);
+
+    if (!commonHeadersResult.ok) {
+      return mapErrorToResponse(commonHeadersResult.error, commonHeadersResult.correlationId, deps.logger);
+    }
 
     try {
-      assertNotEmpty(event.headers, new Error("The request headers are empty"));
-      const lowerCasedHeaders = lowerCaseKeys(event.headers);
-      correlationId = assertNotEmpty(lowerCasedHeaders[deps.env.APIM_CORRELATION_HEADER],
-        new Error("The request headers don't contain the APIM correlation id"));
-      const supplierId = assertNotEmpty(lowerCasedHeaders[deps.env.SUPPLIER_ID_HEADER],
-        new ValidationError(ApiErrorDetail.InvalidRequestMissingSupplierId));
       const letterId = assertNotEmpty( event.pathParameters?.id,
         new ValidationError(ApiErrorDetail.InvalidRequestMissingLetterIdPathParameter));
 
       return {
         statusCode: 303,
         headers: {
-          'Location': await getLetterDataUrl(supplierId, letterId, deps)
+          'Location': await getLetterDataUrl(commonHeadersResult.value.supplierId, letterId, deps)
         },
         body: ''
       };
     }
     catch (error) {
-      return mapErrorToResponse(error, correlationId, deps.logger);
+      return mapErrorToResponse(error, commonHeadersResult.value.correlationId, deps.logger);
     }
   }
 };

lambdas/api-handler/src/handlers/get-letters.ts

@@ -1,6 +1,6 @@
 import { APIGatewayProxyEventQueryStringParameters, APIGatewayProxyHandler } from "aws-lambda";
 import { getLettersForSupplier } from "../services/letter-operations";
-import { assertNotEmpty, lowerCaseKeys } from "../utils/validation";
+import { validateCommonHeaders } from "../utils/validation";
 import { ApiErrorDetail } from '../contracts/errors';
 import { mapErrorToResponse } from "../mappers/error-mapper";
 import { ValidationError } from "../errors";
@@ -19,21 +19,19 @@ export function createGetLettersHandler(deps: Deps): APIGatewayProxyHandler {
 
   return async (event) => {
 
-    const { maxLimit } = getMaxLimit();
+    const commonHeadersResult = validateCommonHeaders(event.headers, deps);
+
+    if (!commonHeadersResult.ok) {
+      return mapErrorToResponse(commonHeadersResult.error, commonHeadersResult.correlationId, deps.logger);
+    }
 
-    let correlationId: string | undefined;
+    const { maxLimit } = getMaxLimit();
 
     try {
-      assertNotEmpty(event.headers, new Error("The request headers are empty"));
-      const lowerCasedHeaders = lowerCaseKeys(event.headers);
-      correlationId = assertNotEmpty(lowerCasedHeaders[deps.env.APIM_CORRELATION_HEADER],
-        new Error("The request headers don't contain the APIM correlation id"));
-      const supplierId = assertNotEmpty(lowerCasedHeaders[deps.env.SUPPLIER_ID_HEADER],
-        new ValidationError(ApiErrorDetail.InvalidRequestMissingSupplierId));
       const limitNumber = getLimitOrDefault(event.queryStringParameters, maxLimit, deps.logger);
 
       const letters = await getLettersForSupplier(
-        supplierId,
+        commonHeadersResult.value.supplierId,
         status,
         limitNumber,
         deps.letterRepo,
@@ -43,7 +41,7 @@ export function createGetLettersHandler(deps: Deps): APIGatewayProxyHandler {
 
       deps.logger.info({
         description: 'Pending letters successfully fetched',
-        supplierId,
+        supplierId: commonHeadersResult.value.supplierId,
         limitNumber,
         status,
         lettersCount: letters.length
@@ -55,7 +53,7 @@ export function createGetLettersHandler(deps: Deps): APIGatewayProxyHandler {
       };
     }
     catch (error) {
-      return mapErrorToResponse(error, correlationId, deps.logger);
+      return mapErrorToResponse(error, commonHeadersResult.value.correlationId, deps.logger);
     }
   }
 };

lambdas/api-handler/src/handlers/patch-letter.ts

@@ -4,7 +4,7 @@ import { PatchLetterRequest, PatchLetterRequestSchema } from '../contracts/lette
 import { ApiErrorDetail } from '../contracts/errors';
 import { ValidationError } from '../errors';
 import { mapErrorToResponse } from '../mappers/error-mapper';
-import { assertNotEmpty, lowerCaseKeys } from '../utils/validation';
+import { assertNotEmpty, validateCommonHeaders } from '../utils/validation';
 import { mapToLetterDto } from '../mappers/letter-mapper';
 import type { Deps } from "../config/deps";
 
@@ -13,15 +13,13 @@ export function createPatchLetterHandler(deps: Deps): APIGatewayProxyHandler {
 
   return async (event) => {
 
-    let correlationId: string | undefined;
+    const commonHeadersResult = validateCommonHeaders(event.headers, deps);
+
+    if (!commonHeadersResult.ok) {
+      return mapErrorToResponse(commonHeadersResult.error, commonHeadersResult.correlationId, deps.logger);
+    }
 
     try {
-      assertNotEmpty(event.headers, new Error('The request headers are empty'));
-      const lowerCasedHeaders = lowerCaseKeys(event.headers);
-      correlationId = assertNotEmpty(lowerCasedHeaders[deps.env.APIM_CORRELATION_HEADER],
-        new Error("The request headers don't contain the APIM correlation id"));
-      const supplierId = assertNotEmpty(lowerCasedHeaders[deps.env.SUPPLIER_ID_HEADER],
-        new ValidationError(ApiErrorDetail.InvalidRequestMissingSupplierId));
       const letterId = assertNotEmpty( event.pathParameters?.id,
         new ValidationError(ApiErrorDetail.InvalidRequestMissingLetterIdPathParameter));
       const body = assertNotEmpty(event.body, new ValidationError(ApiErrorDetail.InvalidRequestMissingBody));
@@ -37,15 +35,15 @@ export function createPatchLetterHandler(deps: Deps): APIGatewayProxyHandler {
         else throw error;
       }
 
-      const result = await patchLetterStatus(mapToLetterDto(patchLetterRequest, supplierId), letterId, deps.letterRepo);
+      const updatedLetter = await patchLetterStatus(mapToLetterDto(patchLetterRequest, commonHeadersResult.value.supplierId), letterId, deps.letterRepo);
 
       return {
         statusCode: 200,
-        body: JSON.stringify(result, null, 2)
+        body: JSON.stringify(updatedLetter, null, 2)
       };
 
     } catch (error) {
-      return mapErrorToResponse(error, correlationId, deps.logger);
+      return mapErrorToResponse(error, commonHeadersResult.value.correlationId, deps.logger);
     }
   };
 };

lambdas/api-handler/src/utils/validation.ts

@@ -1,3 +1,11 @@
+import { APIGatewayProxyEventHeaders } from "aws-lambda";
+import { EnvVars } from "../config/env";
+import { ValidationError } from "../errors";
+import { ApiErrorDetail } from "../contracts/errors";
+import { mapErrorToResponse } from "../mappers/error-mapper";
+import { getLetterDataUrl } from "../services/letter-operations";
+import { Deps } from "../config/deps";
+
 export function assertNotEmpty<T>(
   value: T | null | undefined,
   error: Error
@@ -20,3 +28,29 @@ export function assertNotEmpty<T>(
 export function lowerCaseKeys(obj: Record<string, any>): Record<string, any> {
   return Object.fromEntries(Object.entries(obj).map(([k, v]) => [k.toLowerCase(), v]));
 }
+
+export function validateCommonHeaders(headers: APIGatewayProxyEventHeaders, deps: Deps
+): { ok: true; value: {correlationId: string, supplierId: string } } | { ok: false; error: Error; correlationId?: string } {
+
+  if (!headers || Object.keys(headers).length === 0) {
+    return { ok: false, error: new Error("The request headers are empty") };
+  }
+
+  const lowerCasedHeaders = lowerCaseKeys(headers);
+
+  const correlationId = lowerCasedHeaders[deps.env.APIM_CORRELATION_HEADER];
+  if (!correlationId) {
+    return { ok: false, error: new Error("The request headers don't contain the APIM correlation id") };
+  }
+
+  const supplierId = lowerCasedHeaders[deps.env.SUPPLIER_ID_HEADER];
+  if (!supplierId) {
+    return {
+      ok: false,
+      error: new ValidationError(ApiErrorDetail.InvalidRequestMissingSupplierId),
+      correlationId,
+    };
+  }
+
+  return { ok: true, value: { correlationId, supplierId } };
+}