Add basic pagination and json:api response

Author: francisco-videira-nhs

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

@@ -3,15 +3,30 @@ import type { Context } from 'aws-lambda';
 import { mockDeep } from 'jest-mock-extended';
 
 describe('API Lambda handler', () => {
-  it('returns 200 OK with "Here are some letters: [L1, L2, L3]" for the root path', async () => {
+  it('returns 200 OK with basic paginated resources', async () => {
     const event = { path: '/letters' };
     const context = mockDeep<Context>();
     const callback = jest.fn();
     const result = await getLetters(event, context, callback);
 
+    const expected = {
+      "links": {
+        "self": "/letters?page=1",
+        "first": "/letters?page=1",
+        "last": "/letters?page=1",
+        "next": "/letters?page=1",
+        "prev": "/letters?page=1"
+      },
+      "data": [
+        { "type": "letter", "id": "l1" },
+        { "type": "letter", "id": "l2" },
+        { "type": "letter", "id": "l3" }
+      ]
+    }
+
     expect(result).toEqual({
       statusCode: 200,
-      body: 'Here are some letters: [L1, L2, L3]',
+      body: JSON.stringify(expected),
     });
   });
 

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

@@ -1,12 +1,16 @@
-// Replace me with the actual code for your Lambda function
 import { Handler, APIGatewayProxyEvent, APIGatewayProxyResult } from 'aws-lambda';
 
+const storedLetters: string[] = ["l1", "l2", "l3"];
+
 export const getLetters: Handler = async (event: APIGatewayProxyEvent): Promise<APIGatewayProxyResult> => {
 
   if (event.path === '/letters') {
+
+    const response = createGetLettersResponse(event.path, storedLetters);
+
     return {
       statusCode: 200,
-      body: 'Here are some letters: [L1, L2, L3]',
+      body: JSON.stringify(response)
     };
   }
 
@@ -15,3 +19,40 @@ export const getLetters: Handler = async (event: APIGatewayProxyEvent): Promise<
     body: 'Not Found',
   };
 };
+
+interface Link {
+  self: string;
+  first: string;
+  last: string;
+  next?: string;
+  prev?: string;
+}
+
+interface Resource {
+  type: string;
+  id: string;
+}
+
+interface GetLettersResponse {
+  links: Link;
+  data: Resource[];
+}
+
+function createGetLettersResponse(
+  baseUrl: string,
+  letters: string[]
+): GetLettersResponse {
+  return {
+    links: {
+      self: `${baseUrl}?page=1`,
+      first: `${baseUrl}?page=1`,
+      last: `${baseUrl}?page=1`,
+      next: `${baseUrl}?page=1`,
+      prev: `${baseUrl}?page=1`
+    },
+    data: letters.map((letterId) => ({
+      type: "letter",
+      id: letterId,
+    })),
+  };
+}