Add tests for sonar coverage

Author: francisco-videira-nhs

lambdas/api-handler/src/config/__tests__/deps.test.ts

@@ -0,0 +1,83 @@
+
+import type { Deps } from '../deps';
+
+describe('getDeps()', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+    jest.resetModules();
+
+    // pino
+    jest.mock('pino', () => ({
+      __esModule: true,
+      default: jest.fn(() => ({
+        info: jest.fn(),
+        error: jest.fn(),
+        warn: jest.fn(),
+        debug: jest.fn(),
+      })),
+    }));
+
+    jest.mock('@aws-sdk/client-s3', () => ({
+      S3Client: jest.fn(),
+    }));
+
+    // Repo client
+    jest.mock('../../../../../internal/datastore', () => ({
+      LetterRepository: jest.fn(),
+    }));
+
+    // Env
+    jest.mock('../env', () => ({
+      lambdaEnv: {
+        LETTERS_TABLE_NAME: 'LettersTable',
+        LETTER_TTL_HOURS: '24',
+        SUPPLIER_ID_HEADER: 'nhsd-supplier-id',
+        APIM_CORRELATION_HEADER: 'nhsd-correlation-id',
+      },
+    }));
+  });
+
+  test('constructs deps and wires repository config correctly', async () => {
+    // get current mock instances
+    const { S3Client } = jest.requireMock('@aws-sdk/client-s3') as { S3Client: jest.Mock };
+    const pinoMock = jest.requireMock('pino') as { default: jest.Mock };
+    const { LetterRepository } = jest.requireMock('../../../../../internal/datastore') as { LetterRepository: jest.Mock };
+
+    const { getDeps } = require('../deps');
+    const deps: Deps = getDeps();
+
+    expect(S3Client).toHaveBeenCalledTimes(1);
+    expect(pinoMock.default).toHaveBeenCalledTimes(1);
+
+    expect(LetterRepository).toHaveBeenCalledTimes(1);
+    const repoCtorArgs = (LetterRepository as jest.Mock).mock.calls[0];
+    expect(repoCtorArgs[2]).toEqual({
+      lettersTableName: 'LettersTable',
+      ttlHours: 24
+    });
+
+    expect(deps.env).toEqual({
+      LETTERS_TABLE_NAME: 'LettersTable',
+      LETTER_TTL_HOURS: '24',
+      SUPPLIER_ID_HEADER: 'nhsd-supplier-id',
+      APIM_CORRELATION_HEADER: 'nhsd-correlation-id',
+    });
+  });
+
+  test('is a singleton (second call returns the same object; constructors not re-run)', async () => {
+    // get current mock instances
+    const { S3Client } = jest.requireMock('@aws-sdk/client-s3') as { S3Client: jest.Mock };
+    const pinoMock = jest.requireMock('pino') as { default: jest.Mock };
+    const { LetterRepository } = jest.requireMock('../../../../../internal/datastore') as { LetterRepository: jest.Mock };
+
+    const { getDeps } = require('../deps');
+
+    const first = getDeps();
+    const second = getDeps();
+
+    expect(first).toBe(second);
+    expect(S3Client).toHaveBeenCalledTimes(1);
+    expect(LetterRepository).toHaveBeenCalledTimes(1);
+    expect(pinoMock.default).toHaveBeenCalledTimes(1);
+  });
+});

lambdas/api-handler/src/config/__tests__/env.test.ts

@@ -0,0 +1,39 @@
+describe('lambdaEnv', () => {
+  const OLD_ENV = process.env;
+
+  beforeEach(() => {
+    jest.resetModules(); // Clears cached modules
+    process.env = { ...OLD_ENV }; // Clone original env
+  });
+
+  afterAll(() => {
+    process.env = OLD_ENV; // Restore
+  });
+
+  it('should load all environment variables successfully', () => {
+    process.env.SUPPLIER_ID_HEADER = 'x-supplier-id';
+    process.env.APIM_CORRELATION_HEADER = 'x-correlation-id';
+    process.env.LETTERS_TABLE_NAME = 'letters-table';
+    process.env.LETTER_TTL_HOURS = '24';
+
+    const { lambdaEnv } = require('../env');
+
+    expect(lambdaEnv).toEqual({
+      SUPPLIER_ID_HEADER: 'x-supplier-id',
+      APIM_CORRELATION_HEADER: 'x-correlation-id',
+      LETTERS_TABLE_NAME: 'letters-table',
+      LETTER_TTL_HOURS: '24'
+    });
+  });
+
+  it('should throw if a required env var is missing', () => {
+    process.env.SUPPLIER_ID_HEADER = 'x-supplier-id';
+    process.env.APIM_CORRELATION_HEADER = 'x-correlation-id';
+    process.env.LETTERS_TABLE_NAME = undefined; // simulate missing var
+    process.env.LETTER_TTL_HOURS = '24';
+
+    expect(() => require('../env')).toThrow(
+      'Missing required env var: LETTERS_TABLE_NAME'
+    );
+  });
+});

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

@@ -44,7 +44,6 @@ describe('API Lambda handler', () => {
 
   beforeEach(() => {
     jest.clearAllMocks();
-    jest.resetModules();
   });
 
   it('returns 303 Found with a pre signed url', async () => {