unit tests fixin

src/services/db.test.ts

@@ -3,13 +3,14 @@ import * as db from './db';
 import bcrypt from 'bcrypt';
 import { testPool } from '../tests/setup/test-db';
 
-// Mock the source of the database connection. This tells Vitest that whenever
-// any module tries to import from './db/connection', it should instead get
-// the exports from our mock object defined here. This is the key to ensuring
-// all db service functions use the test database pool.
-vi.mock('./db/connection', async (importOriginal) => {
-  const actual = await importOriginal<typeof import('./db/connection')>();
-  return { ...actual, pool: testPool };
+// Mock the 'pg' package. Whenever 'new Pool()' is called anywhere in the code
+// under test (specifically in `src/services/db/connection.ts`), it will be
+// intercepted. Instead of creating a real production pool, it will return our
+// `testPool`. This is the most reliable way to ensure all database interactions
+// in tests use the test database.
+vi.mock('pg', async (importOriginal) => {
+  const pg = await importOriginal<typeof import('pg')>();
+  return { ...pg, Pool: vi.fn(() => testPool) };
 });
 
 describe('Database Service Integration Tests', () => {

src/services/db/__mocks__/index.ts

@@ -1,15 +0,0 @@
-// src/services/db/__mocks__/index.ts
-import { vi } from 'vitest';
-import { testPool } from '../../../tests/setup/test-db';
-
-// This is the magic. We import the real module...
-const actualDbModule = await vi.importActual<typeof import('..')>('..');
-
-// ...then we replace its exported `pool` with our dedicated test pool.
-actualDbModule.pool = testPool;
-
-// Now, we re-export the entire module. Any test that imports from `src/services/db`
-// will now get the real functions, but those functions will be operating on the
-// test database pool instead of the production one.
-export const { pool, ...rest } = actualDbModule;
-export default { pool, ...rest };

src/services/shopping-list.test.ts

@@ -3,13 +3,14 @@ import * as db from './db';
 import { testPool } from '../tests/setup/test-db';
 import bcrypt from 'bcrypt';
 
-// Mock the source of the database connection. This tells Vitest that whenever
-// any module tries to import from './db/connection', it should instead get
-// the exports from our mock object defined here. This ensures all db service
-// functions in this test file use the test database pool.
-vi.mock('./db/connection', async (importOriginal) => {
-  const actual = await importOriginal<typeof import('./db/connection')>();
-  return { ...actual, pool: testPool };
+// Mock the 'pg' package. Whenever 'new Pool()' is called anywhere in the code
+// under test (specifically in `src/services/db/connection.ts`), it will be
+// intercepted. Instead of creating a real production pool, it will return our
+// `testPool`. This ensures all database interactions in this test file use the
+// test database, resolving the circular dependency error.
+vi.mock('pg', async (importOriginal) => {
+  const pg = await importOriginal<typeof import('pg')>();
+  return { ...pg, Pool: vi.fn(() => testPool) };
 });
 
 describe('Shopping List DB Service Tests', () => {