Refactor: Introduce requiredString helper for consistent validation across routes and services

src/routes/auth.routes.test.ts

@@ -1,12 +1,11 @@
 // src/routes/auth.routes.test.ts
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import supertest from 'supertest';
-import { Request, Response, NextFunction, RequestHandler } from 'express';
+import { Request, Response, NextFunction } from 'express';
 import cookieParser from 'cookie-parser';
 import * as bcrypt from 'bcrypt'; 
 import { createMockUserProfile, createMockUserWithPasswordHash } from '../tests/utils/mockFactories';
 import { mockLogger } from '../tests/utils/mockLogger';
-import { createTestApp } from '../tests/utils/createTestApp';
 
 // --- FIX: Hoist passport mocks to be available for vi.mock ---
 const passportMocks = vi.hoisted(() => {
@@ -199,7 +198,10 @@ describe('Auth Routes (/api/auth)', () => {
       expect(response.status).toBe(400);
       // The validation middleware returns errors in an array.
       // We check if any of the error messages contain the expected text.
-      const errorMessages = response.body.errors?.map((e: any) => e.message).join(' ');
+      interface ZodError {
+        message: string;
+      }
+      const errorMessages = response.body.errors?.map((e: ZodError) => e.message).join(' ');
       expect(errorMessages).toMatch(/Password is too weak/i);
     });
 
@@ -468,11 +470,12 @@ describe('Auth Routes (/api/auth)', () => {
     });
     
      it('should return 403 if refresh token is invalid', async () => {
-        vi.mocked(db.userRepo.findUserByRefreshToken).mockRejectedValue(new Error('Invalid or expired refresh token.'));
+        // Mock finding no user for this token, which should trigger the 403 logic
+        vi.mocked(db.userRepo.findUserByRefreshToken).mockResolvedValue(undefined as any);
         
         const response = await supertest(app)
         .post('/api/auth/refresh-token')
-        .set('Cookie', 'refreshToken=invalid-token'); // This was a duplicate, fixed.
+        .set('Cookie', 'refreshToken=invalid-token');
         
         expect(response.status).toBe(403);
      });