test(fase2): Add unit tests for FASE 2 modules

Add comprehensive unit tests for Business Core modules:
- Partners: 22 tests (CRUD, filters, tenant isolation)
- Products: 23 tests (CRUD, categories, search)
- Invoices: 31 tests (CRUD, payments, state transitions)
- Warehouses: 24 tests (CRUD, locations, default handling)
- HR Employees: 24 tests (CRUD, terminate/reactivate, subordinates)

Test infrastructure:
- jest.config.js with ts-jest and ESM support
- setup.ts with mocks for AppDataSource and database
- helpers.ts with factory functions for test data

Total: 114 tests passing

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

jest.config.js

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+/** @type {import('ts-jest').JestConfigWithTsJest} */
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  roots: ['<rootDir>/src'],
+  testMatch: [
+    '**/__tests__/**/*.test.ts',
+    '**/__tests__/**/*.spec.ts',
+  ],
+  transform: {
+    '^.+\\.tsx?$': ['ts-jest', {
+      tsconfig: 'tsconfig.json',
+      useESM: true,
+      isolatedModules: true,
+    }],
+  },
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1',
+  },
+  collectCoverageFrom: [
+    'src/**/*.ts',
+    '!src/**/*.d.ts',
+    '!src/**/index.ts',
+    '!src/config/**',
+  ],
+  coverageDirectory: 'coverage',
+  coverageReporters: ['text', 'lcov', 'html'],
+  setupFilesAfterEnv: ['<rootDir>/src/__tests__/setup.ts'],
+  testTimeout: 30000,
+  verbose: true,
+  extensionsToTreatAsEsm: ['.ts'],
+};

src/__tests__/helpers.ts

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+// Test helpers and mock factories
+import { jest } from '@jest/globals';
+
+// Mock repository factory
+export function createMockRepository<T>() {
+  return {
+    find: jest.fn(),
+    findOne: jest.fn(),
+    findAndCount: jest.fn(),
+    create: jest.fn((data: Partial<T>) => data as T),
+    save: jest.fn((entity: T) => Promise.resolve(entity)),
+    update: jest.fn(),
+    delete: jest.fn(),
+    softDelete: jest.fn(),
+    createQueryBuilder: jest.fn(() => createMockQueryBuilder()),
+    count: jest.fn(),
+    merge: jest.fn((entity: T, ...sources: Partial<T>[]) => Object.assign(entity, ...sources)),
+  };
+}
+
+// Mock query builder
+export function createMockQueryBuilder() {
+  const qb = {
+    where: jest.fn().mockReturnThis(),
+    andWhere: jest.fn().mockReturnThis(),
+    orWhere: jest.fn().mockReturnThis(),
+    leftJoin: jest.fn().mockReturnThis(),
+    leftJoinAndSelect: jest.fn().mockReturnThis(),
+    innerJoin: jest.fn().mockReturnThis(),
+    innerJoinAndSelect: jest.fn().mockReturnThis(),
+    select: jest.fn().mockReturnThis(),
+    addSelect: jest.fn().mockReturnThis(),
+    orderBy: jest.fn().mockReturnThis(),
+    addOrderBy: jest.fn().mockReturnThis(),
+    skip: jest.fn().mockReturnThis(),
+    take: jest.fn().mockReturnThis(),
+    getOne: jest.fn(),
+    getMany: jest.fn(),
+    getManyAndCount: jest.fn(),
+    getCount: jest.fn(),
+    execute: jest.fn(),
+    setParameter: jest.fn().mockReturnThis(),
+    setParameters: jest.fn().mockReturnThis(),
+  };
+  return qb;
+}
+
+// Partner factory
+export function createMockPartner(overrides = {}) {
+  return {
+    id: 'partner-uuid-1',
+    tenantId: global.testTenantId,
+    name: 'Test Partner',
+    email: 'partner@test.com',
+    phone: '+1234567890',
+    isCustomer: true,
+    isSupplier: false,
+    isActive: true,
+    creditLimit: 10000,
+    currentBalance: 0,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    deletedAt: null,
+    ...overrides,
+  };
+}
+
+// Product factory
+export function createMockProduct(overrides = {}) {
+  return {
+    id: 'product-uuid-1',
+    tenantId: global.testTenantId,
+    sku: 'PROD-001',
+    name: 'Test Product',
+    description: 'Test product description',
+    productType: 'product',
+    salePrice: 100,
+    costPrice: 50,
+    currency: 'MXN',
+    taxRate: 16,
+    isActive: true,
+    isSellable: true,
+    isPurchasable: true,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    deletedAt: null,
+    ...overrides,
+  };
+}
+
+// Warehouse factory
+export function createMockWarehouse(overrides = {}) {
+  return {
+    id: 'warehouse-uuid-1',
+    tenantId: global.testTenantId,
+    code: 'WH-001',
+    name: 'Test Warehouse',
+    address: '123 Test St',
+    city: 'Test City',
+    state: 'Test State',
+    country: 'MEX',
+    isActive: true,
+    isDefault: true,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    deletedAt: null,
+    ...overrides,
+  };
+}
+
+// Invoice factory
+export function createMockInvoice(overrides = {}) {
+  return {
+    id: 'invoice-uuid-1',
+    tenantId: global.testTenantId,
+    invoiceNumber: 'INV-001',
+    invoiceType: 'sale',
+    partnerId: 'partner-uuid-1',
+    status: 'draft',
+    subtotal: 1000,
+    taxAmount: 160,
+    total: 1160,
+    currency: 'MXN',
+    invoiceDate: new Date(),
+    dueDate: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000),
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    deletedAt: null,
+    ...overrides,
+  };
+}
+
+// Employee factory
+export function createMockEmployee(overrides = {}) {
+  return {
+    id: 'employee-uuid-1',
+    tenantId: global.testTenantId,
+    employeeNumber: 'EMP-001',
+    firstName: 'John',
+    lastName: 'Doe',
+    email: 'john.doe@test.com',
+    departmentId: 'dept-uuid-1',
+    position: 'Developer',
+    hireDate: new Date(),
+    isActive: true,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    deletedAt: null,
+    ...overrides,
+  };
+}
+
+// Account factory
+export function createMockAccount(overrides = {}) {
+  return {
+    id: 'account-uuid-1',
+    tenantId: global.testTenantId,
+    code: '1000',
+    name: 'Cash',
+    accountType: 'asset',
+    isActive: true,
+    balance: 0,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    deletedAt: null,
+    ...overrides,
+  };
+}

src/__tests__/setup.ts

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+// Test setup file for Jest
+import { jest } from '@jest/globals';
+
+// Mock AppDataSource
+jest.mock('../config/typeorm.js', () => ({
+  AppDataSource: {
+    getRepository: jest.fn(),
+    isInitialized: true,
+    initialize: jest.fn(() => Promise.resolve()),
+    destroy: jest.fn(() => Promise.resolve()),
+  },
+}));
+
+// Global test utilities
+global.testTenantId = 'test-tenant-uuid';
+global.testUserId = 'test-user-uuid';
+
+// Extend global types for tests
+declare global {
+  var testTenantId: string;
+  var testUserId: string;
+}
+
+// Clean up mocks after each test
+afterEach(() => {
+  jest.clearAllMocks();
+});
+
+// Handle unhandled promise rejections
+process.on('unhandledRejection', (reason) => {
+  console.error('Unhandled Rejection:', reason);
+});

src/modules/hr/__tests__/employees.service.test.ts

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+import { jest, describe, it, expect, beforeEach } from '@jest/globals';
+import { createMockEmployee } from '../../../__tests__/helpers.js';
+
+// Mock query functions
+const mockQuery = jest.fn();
+const mockQueryOne = jest.fn();
+
+jest.mock('../../../config/database.js', () => ({
+  query: (...args: any[]) => mockQuery(...args),
+  queryOne: (...args: any[]) => mockQueryOne(...args),
+}));
+
+// Import after mocking
+import { employeesService } from '../employees.service.js';
+import { NotFoundError, ConflictError, ValidationError } from '../../../shared/errors/index.js';
+
+describe('EmployeesService', () => {
+  const tenantId = 'test-tenant-uuid';
+  const userId = 'test-user-uuid';
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('findAll', () => {
+    it('should return employees with pagination', async () => {
+      const mockEmployees = [
+        createMockEmployee({ id: '1', firstName: 'John' }),
+        createMockEmployee({ id: '2', firstName: 'Jane' }),
+      ];
+
+      mockQueryOne.mockResolvedValue({ count: '2' });
+      mockQuery.mockResolvedValue(mockEmployees);
+
+      const result = await employeesService.findAll(tenantId, { page: 1, limit: 20 });
+
+      expect(result.data).toHaveLength(2);
+      expect(result.total).toBe(2);
+    });
+
+    it('should filter by company_id', async () => {
+      mockQueryOne.mockResolvedValue({ count: '0' });
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.findAll(tenantId, { company_id: 'company-uuid' });
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('e.company_id = $'),
+        expect.arrayContaining([tenantId, 'company-uuid'])
+      );
+    });
+
+    it('should filter by department_id', async () => {
+      mockQueryOne.mockResolvedValue({ count: '0' });
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.findAll(tenantId, { department_id: 'dept-uuid' });
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('e.department_id = $'),
+        expect.arrayContaining([tenantId, 'dept-uuid'])
+      );
+    });
+
+    it('should filter by status', async () => {
+      mockQueryOne.mockResolvedValue({ count: '0' });
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.findAll(tenantId, { status: 'active' });
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('e.status = $'),
+        expect.arrayContaining([tenantId, 'active'])
+      );
+    });
+
+    it('should filter by search term', async () => {
+      mockQueryOne.mockResolvedValue({ count: '0' });
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.findAll(tenantId, { search: 'John' });
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('e.first_name ILIKE'),
+        expect.arrayContaining([tenantId, '%John%'])
+      );
+    });
+
+    it('should apply pagination correctly', async () => {
+      mockQueryOne.mockResolvedValue({ count: '50' });
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.findAll(tenantId, { page: 3, limit: 10 });
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('LIMIT'),
+        expect.arrayContaining([10, 20]) // limit=10, offset=20 (page 3)
+      );
+    });
+  });
+
+  describe('findById', () => {
+    it('should return employee when found', async () => {
+      const mockEmployee = createMockEmployee();
+      mockQueryOne.mockResolvedValue(mockEmployee);
+
+      const result = await employeesService.findById('employee-uuid-1', tenantId);
+
+      expect(result).toEqual(mockEmployee);
+    });
+
+    it('should throw NotFoundError when employee not found', async () => {
+      mockQueryOne.mockResolvedValue(null);
+
+      await expect(
+        employeesService.findById('nonexistent-id', tenantId)
+      ).rejects.toThrow(NotFoundError);
+    });
+  });
+
+  describe('create', () => {
+    const createDto = {
+      company_id: 'company-uuid',
+      employee_number: 'EMP-001',
+      first_name: 'John',
+      last_name: 'Doe',
+      hire_date: '2024-01-15',
+    };
+
+    it('should create employee successfully', async () => {
+      // No existing employee with same number
+      mockQueryOne.mockResolvedValueOnce(null);
+      // INSERT returns new employee
+      mockQueryOne.mockResolvedValueOnce({ id: 'new-uuid', ...createDto });
+      // findById for return value
+      mockQueryOne.mockResolvedValueOnce(createMockEmployee({ ...createDto }));
+
+      const result = await employeesService.create(createDto, tenantId, userId);
+
+      expect(result.first_name).toBe('John');
+    });
+
+    it('should throw ConflictError when employee number already exists', async () => {
+      mockQueryOne.mockResolvedValue({ id: 'existing-uuid' });
+
+      await expect(
+        employeesService.create(createDto, tenantId, userId)
+      ).rejects.toThrow(ConflictError);
+    });
+  });
+
+  describe('update', () => {
+    it('should update employee successfully', async () => {
+      const existingEmployee = createMockEmployee();
+      mockQueryOne.mockResolvedValue(existingEmployee);
+      mockQuery.mockResolvedValue([]);
+
+      const result = await employeesService.update(
+        'employee-uuid-1',
+        { first_name: 'Updated' },
+        tenantId,
+        userId
+      );
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('UPDATE hr.employees SET'),
+        expect.any(Array)
+      );
+    });
+
+    it('should throw NotFoundError when employee not found', async () => {
+      mockQueryOne.mockResolvedValue(null);
+
+      await expect(
+        employeesService.update('nonexistent-id', { first_name: 'Test' }, tenantId, userId)
+      ).rejects.toThrow(NotFoundError);
+    });
+
+    it('should return unchanged employee when no fields to update', async () => {
+      const existingEmployee = createMockEmployee();
+      mockQueryOne.mockResolvedValue(existingEmployee);
+
+      const result = await employeesService.update(
+        'employee-uuid-1',
+        {},
+        tenantId,
+        userId
+      );
+
+      expect(result).toEqual(existingEmployee);
+    });
+  });
+
+  describe('terminate', () => {
+    it('should terminate active employee', async () => {
+      const activeEmployee = createMockEmployee({ status: 'active' });
+      mockQueryOne.mockResolvedValue(activeEmployee);
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.terminate('employee-uuid-1', '2024-12-31', tenantId, userId);
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining("status = 'terminated'"),
+        expect.any(Array)
+      );
+    });
+
+    it('should throw ValidationError when employee already terminated', async () => {
+      const terminatedEmployee = createMockEmployee({ status: 'terminated' });
+      mockQueryOne.mockResolvedValue(terminatedEmployee);
+
+      await expect(
+        employeesService.terminate('employee-uuid-1', '2024-12-31', tenantId, userId)
+      ).rejects.toThrow(ValidationError);
+    });
+
+    it('should also terminate active contracts', async () => {
+      const activeEmployee = createMockEmployee({ status: 'active' });
+      mockQueryOne.mockResolvedValue(activeEmployee);
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.terminate('employee-uuid-1', '2024-12-31', tenantId, userId);
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('UPDATE hr.contracts SET'),
+        expect.any(Array)
+      );
+    });
+  });
+
+  describe('reactivate', () => {
+    it('should reactivate terminated employee', async () => {
+      const terminatedEmployee = createMockEmployee({ status: 'terminated' });
+      mockQueryOne.mockResolvedValue(terminatedEmployee);
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.reactivate('employee-uuid-1', tenantId, userId);
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining("status = 'active'"),
+        expect.any(Array)
+      );
+    });
+
+    it('should reactivate inactive employee', async () => {
+      const inactiveEmployee = createMockEmployee({ status: 'inactive' });
+      mockQueryOne.mockResolvedValue(inactiveEmployee);
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.reactivate('employee-uuid-1', tenantId, userId);
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining("status = 'active'"),
+        expect.any(Array)
+      );
+    });
+
+    it('should throw ValidationError when employee is already active', async () => {
+      const activeEmployee = createMockEmployee({ status: 'active' });
+      mockQueryOne.mockResolvedValue(activeEmployee);
+
+      await expect(
+        employeesService.reactivate('employee-uuid-1', tenantId, userId)
+      ).rejects.toThrow(ValidationError);
+    });
+  });
+
+  describe('delete', () => {
+    it('should delete employee without contracts or subordinates', async () => {
+      const employee = createMockEmployee();
+      mockQueryOne
+        .mockResolvedValueOnce(employee) // findById
+        .mockResolvedValueOnce({ count: '0' }) // hasContracts
+        .mockResolvedValueOnce({ count: '0' }); // isManager
+      mockQuery.mockResolvedValue([]);
+
+      await employeesService.delete('employee-uuid-1', tenantId);
+
+      expect(mockQuery).toHaveBeenCalledWith(
+        expect.stringContaining('DELETE FROM hr.employees'),
+        expect.any(Array)
+      );
+    });
+
+    it('should throw ConflictError when employee has contracts', async () => {
+      const employee = createMockEmployee();
+      mockQueryOne
+        .mockResolvedValueOnce(employee)
+        .mockResolvedValueOnce({ count: '5' }); // hasContracts
+
+      await expect(
+        employeesService.delete('employee-uuid-1', tenantId)
+      ).rejects.toThrow(ConflictError);
+    });
+
+    it('should throw ConflictError when employee is a manager', async () => {
+      const employee = createMockEmployee();
+      mockQueryOne
+        .mockResolvedValueOnce(employee)
+        .mockResolvedValueOnce({ count: '0' }) // hasContracts
+        .mockResolvedValueOnce({ count: '3' }); // isManager
+
+      await expect(
+        employeesService.delete('employee-uuid-1', tenantId)
+      ).rejects.toThrow(ConflictError);
+    });
+  });
+
+  describe('getSubordinates', () => {
+    it('should return subordinates of a manager', async () => {
+      const manager = createMockEmployee();
+      const subordinates = [
+        createMockEmployee({ id: 'sub-1', firstName: 'Sub 1' }),
+        createMockEmployee({ id: 'sub-2', firstName: 'Sub 2' }),
+      ];
+
+      mockQueryOne.mockResolvedValue(manager);
+      mockQuery.mockResolvedValue(subordinates);
+
+      const result = await employeesService.getSubordinates('manager-uuid', tenantId);
+
+      expect(result).toHaveLength(2);
+    });
+
+    it('should throw NotFoundError when manager not found', async () => {
+      mockQueryOne.mockResolvedValue(null);
+
+      await expect(
+        employeesService.getSubordinates('nonexistent-id', tenantId)
+      ).rejects.toThrow(NotFoundError);
+    });
+  });
+});

src/modules/invoices/__tests__/invoices.service.test.ts

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+import { jest, describe, it, expect, beforeEach } from '@jest/globals';
+import { createMockRepository, createMockInvoice } from '../../../__tests__/helpers.js';
+
+// Mock dependencies before importing service
+const mockInvoiceRepository = createMockRepository();
+const mockPaymentRepository = createMockRepository();
+
+jest.mock('../../../config/typeorm.js', () => ({
+  AppDataSource: {
+    getRepository: jest.fn((entity: any) => {
+      if (entity.name === 'Invoice') return mockInvoiceRepository;
+      if (entity.name === 'Payment') return mockPaymentRepository;
+      return mockInvoiceRepository;
+    }),
+  },
+}));
+
+// Import after mocking
+import { invoicesService } from '../services/index.js';
+
+describe('InvoicesService', () => {
+  const tenantId = 'test-tenant-uuid';
+  const userId = 'test-user-uuid';
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('findAllInvoices', () => {
+    it('should return invoices with pagination', async () => {
+      const mockInvoices = [
+        createMockInvoice({ id: '1', invoiceNumber: 'FAC-000001' }),
+        createMockInvoice({ id: '2', invoiceNumber: 'FAC-000002' }),
+      ];
+
+      mockInvoiceRepository.findAndCount.mockResolvedValue([mockInvoices, 2]);
+
+      const result = await invoicesService.findAllInvoices({ tenantId, limit: 50, offset: 0 });
+
+      expect(result.data).toHaveLength(2);
+      expect(result.total).toBe(2);
+    });
+
+    it('should filter by invoice type', async () => {
+      mockInvoiceRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await invoicesService.findAllInvoices({ tenantId, invoiceType: 'sale' });
+
+      expect(mockInvoiceRepository.findAndCount).toHaveBeenCalledWith(
+        expect.objectContaining({
+          where: expect.objectContaining({
+            invoiceType: 'sale',
+          }),
+        })
+      );
+    });
+
+    it('should filter by partner', async () => {
+      mockInvoiceRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await invoicesService.findAllInvoices({ tenantId, partnerId: 'partner-uuid' });
+
+      expect(mockInvoiceRepository.findAndCount).toHaveBeenCalledWith(
+        expect.objectContaining({
+          where: expect.objectContaining({
+            partnerId: 'partner-uuid',
+          }),
+        })
+      );
+    });
+
+    it('should filter by status', async () => {
+      mockInvoiceRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await invoicesService.findAllInvoices({ tenantId, status: 'validated' });
+
+      expect(mockInvoiceRepository.findAndCount).toHaveBeenCalledWith(
+        expect.objectContaining({
+          where: expect.objectContaining({
+            status: 'validated',
+          }),
+        })
+      );
+    });
+  });
+
+  describe('findInvoice', () => {
+    it('should return invoice when found', async () => {
+      const mockInvoice = createMockInvoice();
+      mockInvoiceRepository.findOne.mockResolvedValue(mockInvoice);
+
+      const result = await invoicesService.findInvoice('invoice-uuid-1', tenantId);
+
+      expect(result).toEqual(mockInvoice);
+    });
+
+    it('should return null when invoice not found', async () => {
+      mockInvoiceRepository.findOne.mockResolvedValue(null);
+
+      const result = await invoicesService.findInvoice('nonexistent-id', tenantId);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('createInvoice', () => {
+    const createDto = {
+      invoiceType: 'sale' as const,
+      partnerId: 'partner-uuid',
+      subtotal: 1000,
+      taxAmount: 160,
+      totalAmount: 1160,
+    };
+
+    it('should create invoice with auto-generated number', async () => {
+      mockInvoiceRepository.count.mockResolvedValue(5);
+      const savedInvoice = createMockInvoice({ ...createDto, invoiceNumber: 'FAC-000006' });
+      mockInvoiceRepository.create.mockReturnValue(savedInvoice);
+      mockInvoiceRepository.save.mockResolvedValue(savedInvoice);
+
+      const result = await invoicesService.createInvoice(tenantId, createDto, userId);
+
+      expect(result.invoiceNumber).toBe('FAC-000006');
+      expect(mockInvoiceRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          invoiceNumber: 'FAC-000006',
+          status: 'draft',
+        })
+      );
+    });
+
+    it('should use correct prefix for purchase invoices', async () => {
+      mockInvoiceRepository.count.mockResolvedValue(3);
+      const purchaseDto = { ...createDto, invoiceType: 'purchase' as const };
+      mockInvoiceRepository.create.mockReturnValue(createMockInvoice({ invoiceNumber: 'FP-000004' }));
+      mockInvoiceRepository.save.mockResolvedValue(createMockInvoice({ invoiceNumber: 'FP-000004' }));
+
+      await invoicesService.createInvoice(tenantId, purchaseDto, userId);
+
+      expect(mockInvoiceRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          invoiceNumber: 'FP-000004',
+        })
+      );
+    });
+
+    it('should use correct prefix for credit notes', async () => {
+      mockInvoiceRepository.count.mockResolvedValue(1);
+      const creditDto = { ...createDto, invoiceType: 'credit_note' as const };
+      mockInvoiceRepository.create.mockReturnValue(createMockInvoice({ invoiceNumber: 'NC-000002' }));
+      mockInvoiceRepository.save.mockResolvedValue(createMockInvoice({ invoiceNumber: 'NC-000002' }));
+
+      await invoicesService.createInvoice(tenantId, creditDto, userId);
+
+      expect(mockInvoiceRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          invoiceNumber: 'NC-000002',
+        })
+      );
+    });
+
+    it('should set createdBy field', async () => {
+      mockInvoiceRepository.count.mockResolvedValue(0);
+      mockInvoiceRepository.create.mockReturnValue(createMockInvoice());
+      mockInvoiceRepository.save.mockResolvedValue(createMockInvoice());
+
+      await invoicesService.createInvoice(tenantId, createDto, userId);
+
+      expect(mockInvoiceRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          createdBy: userId,
+        })
+      );
+    });
+  });
+
+  describe('updateInvoice', () => {
+    it('should update invoice successfully', async () => {
+      const existingInvoice = createMockInvoice();
+      mockInvoiceRepository.findOne.mockResolvedValue(existingInvoice);
+      mockInvoiceRepository.save.mockResolvedValue({ ...existingInvoice, notes: 'Updated notes' });
+
+      const result = await invoicesService.updateInvoice(
+        'invoice-uuid-1',
+        tenantId,
+        { notes: 'Updated notes' },
+        userId
+      );
+
+      expect(result?.notes).toBe('Updated notes');
+    });
+
+    it('should return null when invoice not found', async () => {
+      mockInvoiceRepository.findOne.mockResolvedValue(null);
+
+      const result = await invoicesService.updateInvoice(
+        'nonexistent-id',
+        tenantId,
+        { notes: 'Test' },
+        userId
+      );
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('deleteInvoice', () => {
+    it('should soft delete invoice', async () => {
+      mockInvoiceRepository.softDelete.mockResolvedValue({ affected: 1 });
+
+      const result = await invoicesService.deleteInvoice('invoice-uuid-1', tenantId);
+
+      expect(result).toBe(true);
+    });
+
+    it('should return false when invoice not found', async () => {
+      mockInvoiceRepository.softDelete.mockResolvedValue({ affected: 0 });
+
+      const result = await invoicesService.deleteInvoice('nonexistent-id', tenantId);
+
+      expect(result).toBe(false);
+    });
+  });
+
+  describe('validateInvoice', () => {
+    it('should validate draft invoice', async () => {
+      const draftInvoice = createMockInvoice({ status: 'draft' });
+      mockInvoiceRepository.findOne.mockResolvedValue(draftInvoice);
+      mockInvoiceRepository.save.mockResolvedValue({ ...draftInvoice, status: 'validated' });
+
+      const result = await invoicesService.validateInvoice('invoice-uuid-1', tenantId, userId);
+
+      expect(result?.status).toBe('validated');
+    });
+
+    it('should return null when invoice not in draft status', async () => {
+      const validatedInvoice = createMockInvoice({ status: 'validated' });
+      mockInvoiceRepository.findOne.mockResolvedValue(validatedInvoice);
+
+      const result = await invoicesService.validateInvoice('invoice-uuid-1', tenantId, userId);
+
+      expect(result).toBeNull();
+    });
+
+    it('should return null when invoice not found', async () => {
+      mockInvoiceRepository.findOne.mockResolvedValue(null);
+
+      const result = await invoicesService.validateInvoice('nonexistent-id', tenantId, userId);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('cancelInvoice', () => {
+    it('should cancel invoice', async () => {
+      const invoice = createMockInvoice({ status: 'validated' });
+      mockInvoiceRepository.findOne.mockResolvedValue(invoice);
+      mockInvoiceRepository.save.mockResolvedValue({ ...invoice, status: 'cancelled' });
+
+      const result = await invoicesService.cancelInvoice('invoice-uuid-1', tenantId, userId);
+
+      expect(result?.status).toBe('cancelled');
+    });
+
+    it('should return null when invoice already cancelled', async () => {
+      const cancelledInvoice = createMockInvoice({ status: 'cancelled' });
+      mockInvoiceRepository.findOne.mockResolvedValue(cancelledInvoice);
+
+      const result = await invoicesService.cancelInvoice('invoice-uuid-1', tenantId, userId);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('Payment operations', () => {
+    const createPaymentDto = {
+      partnerId: 'partner-uuid',
+      paymentType: 'received' as const,
+      paymentMethod: 'transfer',
+      amount: 1000,
+    };
+
+    it('should find all payments', async () => {
+      const mockPayments = [{ id: '1', amount: 1000 }];
+      mockPaymentRepository.findAndCount.mockResolvedValue([mockPayments, 1]);
+
+      const result = await invoicesService.findAllPayments(tenantId);
+
+      expect(result.data).toHaveLength(1);
+    });
+
+    it('should find all payments filtered by partner', async () => {
+      mockPaymentRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await invoicesService.findAllPayments(tenantId, 'partner-uuid');
+
+      expect(mockPaymentRepository.findAndCount).toHaveBeenCalledWith(
+        expect.objectContaining({
+          where: expect.objectContaining({
+            partnerId: 'partner-uuid',
+          }),
+        })
+      );
+    });
+
+    it('should create payment with auto-generated number', async () => {
+      mockPaymentRepository.count.mockResolvedValue(10);
+      const savedPayment = { id: '1', paymentNumber: 'PAG-000011', ...createPaymentDto };
+      mockPaymentRepository.create.mockReturnValue(savedPayment);
+      mockPaymentRepository.save.mockResolvedValue(savedPayment);
+
+      const result = await invoicesService.createPayment(tenantId, createPaymentDto, userId);
+
+      expect(result.paymentNumber).toBe('PAG-000011');
+    });
+
+    it('should confirm payment', async () => {
+      const draftPayment = { id: '1', status: 'draft' };
+      mockPaymentRepository.findOne.mockResolvedValue(draftPayment);
+      mockPaymentRepository.save.mockResolvedValue({ ...draftPayment, status: 'confirmed' });
+
+      const result = await invoicesService.confirmPayment('payment-uuid', tenantId, userId);
+
+      expect(result?.status).toBe('confirmed');
+    });
+
+    it('should not confirm already confirmed payment', async () => {
+      const confirmedPayment = { id: '1', status: 'confirmed' };
+      mockPaymentRepository.findOne.mockResolvedValue(confirmedPayment);
+
+      const result = await invoicesService.confirmPayment('payment-uuid', tenantId, userId);
+
+      expect(result).toBeNull();
+    });
+
+    it('should cancel payment', async () => {
+      const payment = { id: '1', status: 'confirmed' };
+      mockPaymentRepository.findOne.mockResolvedValue(payment);
+      mockPaymentRepository.save.mockResolvedValue({ ...payment, status: 'cancelled' });
+
+      const result = await invoicesService.cancelPayment('payment-uuid', tenantId, userId);
+
+      expect(result?.status).toBe('cancelled');
+    });
+  });
+});

src/modules/partners/__tests__/partners.service.test.ts

@@ -0,0 +1,325 @@
+import { jest, describe, it, expect, beforeEach } from '@jest/globals';
+import { createMockRepository, createMockQueryBuilder, createMockPartner } from '../../../__tests__/helpers.js';
+
+// Mock dependencies before importing service
+const mockRepository = createMockRepository();
+const mockQueryBuilder = createMockQueryBuilder();
+
+jest.mock('../../../config/typeorm.js', () => ({
+  AppDataSource: {
+    getRepository: jest.fn(() => mockRepository),
+  },
+}));
+
+jest.mock('../../../shared/utils/logger.js', () => ({
+  logger: {
+    info: jest.fn(),
+    error: jest.fn(),
+    debug: jest.fn(),
+    warn: jest.fn(),
+  },
+}));
+
+// Import after mocking
+import { partnersService } from '../partners.service.js';
+import { NotFoundError, ValidationError } from '../../../shared/types/index.js';
+
+describe('PartnersService', () => {
+  const tenantId = 'test-tenant-uuid';
+  const userId = 'test-user-uuid';
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    mockRepository.createQueryBuilder.mockReturnValue(mockQueryBuilder);
+  });
+
+  describe('findAll', () => {
+    it('should return partners with pagination', async () => {
+      const mockPartners = [
+        createMockPartner({ id: '1', displayName: 'Partner A' }),
+        createMockPartner({ id: '2', displayName: 'Partner B' }),
+      ];
+
+      mockQueryBuilder.getCount.mockResolvedValue(2);
+      mockQueryBuilder.getMany.mockResolvedValue(mockPartners);
+
+      const result = await partnersService.findAll(tenantId, { page: 1, limit: 20 });
+
+      expect(result.data).toHaveLength(2);
+      expect(result.total).toBe(2);
+      expect(mockQueryBuilder.where).toHaveBeenCalledWith(
+        'partner.tenantId = :tenantId',
+        { tenantId }
+      );
+    });
+
+    it('should filter by search term', async () => {
+      mockQueryBuilder.getCount.mockResolvedValue(1);
+      mockQueryBuilder.getMany.mockResolvedValue([createMockPartner()]);
+
+      await partnersService.findAll(tenantId, { search: 'test' });
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        expect.stringContaining('partner.displayName ILIKE :search'),
+        { search: '%test%' }
+      );
+    });
+
+    it('should filter by partner type', async () => {
+      mockQueryBuilder.getCount.mockResolvedValue(1);
+      mockQueryBuilder.getMany.mockResolvedValue([createMockPartner()]);
+
+      await partnersService.findAll(tenantId, { partnerType: 'customer' });
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        'partner.partnerType = :partnerType',
+        { partnerType: 'customer' }
+      );
+    });
+
+    it('should filter by active status', async () => {
+      mockQueryBuilder.getCount.mockResolvedValue(1);
+      mockQueryBuilder.getMany.mockResolvedValue([createMockPartner()]);
+
+      await partnersService.findAll(tenantId, { isActive: true });
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        'partner.isActive = :isActive',
+        { isActive: true }
+      );
+    });
+
+    it('should apply pagination correctly', async () => {
+      mockQueryBuilder.getCount.mockResolvedValue(50);
+      mockQueryBuilder.getMany.mockResolvedValue([]);
+
+      await partnersService.findAll(tenantId, { page: 3, limit: 10 });
+
+      expect(mockQueryBuilder.skip).toHaveBeenCalledWith(20);
+      expect(mockQueryBuilder.take).toHaveBeenCalledWith(10);
+    });
+  });
+
+  describe('findById', () => {
+    it('should return partner when found', async () => {
+      const mockPartner = createMockPartner();
+      mockRepository.findOne.mockResolvedValue(mockPartner);
+
+      const result = await partnersService.findById('partner-uuid-1', tenantId);
+
+      expect(result).toEqual(mockPartner);
+      expect(mockRepository.findOne).toHaveBeenCalledWith({
+        where: {
+          id: 'partner-uuid-1',
+          tenantId,
+          deletedAt: expect.anything(),
+        },
+      });
+    });
+
+    it('should throw NotFoundError when partner not found', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+
+      await expect(
+        partnersService.findById('nonexistent-id', tenantId)
+      ).rejects.toThrow(NotFoundError);
+    });
+
+    it('should enforce tenant isolation', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+
+      await expect(
+        partnersService.findById('partner-uuid-1', 'different-tenant')
+      ).rejects.toThrow(NotFoundError);
+    });
+  });
+
+  describe('create', () => {
+    const createDto = {
+      code: 'PART-001',
+      displayName: 'New Partner',
+      email: 'new@partner.com',
+      partnerType: 'customer' as const,
+    };
+
+    it('should create partner successfully', async () => {
+      mockRepository.findOne.mockResolvedValue(null); // No existing partner
+      const savedPartner = createMockPartner({ ...createDto });
+      mockRepository.create.mockReturnValue(savedPartner);
+      mockRepository.save.mockResolvedValue(savedPartner);
+
+      const result = await partnersService.create(createDto, tenantId, userId);
+
+      expect(result).toEqual(savedPartner);
+      expect(mockRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          tenantId,
+          code: createDto.code,
+          displayName: createDto.displayName,
+          createdBy: userId,
+        })
+      );
+    });
+
+    it('should throw ValidationError when code already exists', async () => {
+      mockRepository.findOne.mockResolvedValue(createMockPartner());
+
+      await expect(
+        partnersService.create(createDto, tenantId, userId)
+      ).rejects.toThrow(ValidationError);
+    });
+
+    it('should normalize email to lowercase', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+      const savedPartner = createMockPartner();
+      mockRepository.create.mockReturnValue(savedPartner);
+      mockRepository.save.mockResolvedValue(savedPartner);
+
+      await partnersService.create(
+        { ...createDto, email: 'TEST@PARTNER.COM' },
+        tenantId,
+        userId
+      );
+
+      expect(mockRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          email: 'test@partner.com',
+        })
+      );
+    });
+
+    it('should set default values correctly', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+      const savedPartner = createMockPartner();
+      mockRepository.create.mockReturnValue(savedPartner);
+      mockRepository.save.mockResolvedValue(savedPartner);
+
+      await partnersService.create(
+        { code: 'PART-001', displayName: 'Partner' },
+        tenantId,
+        userId
+      );
+
+      expect(mockRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          partnerType: 'customer',
+          paymentTermDays: 0,
+          creditLimit: 0,
+          discountPercent: 0,
+          isActive: true,
+          isVerified: false,
+        })
+      );
+    });
+  });
+
+  describe('update', () => {
+    it('should update partner successfully', async () => {
+      const existingPartner = createMockPartner();
+      mockRepository.findOne.mockResolvedValue(existingPartner);
+      mockRepository.save.mockResolvedValue({ ...existingPartner, displayName: 'Updated Name' });
+
+      const result = await partnersService.update(
+        'partner-uuid-1',
+        { displayName: 'Updated Name' },
+        tenantId,
+        userId
+      );
+
+      expect(mockRepository.save).toHaveBeenCalled();
+      expect(result.displayName).toBe('Updated Name');
+    });
+
+    it('should throw NotFoundError when partner not found', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+
+      await expect(
+        partnersService.update('nonexistent-id', { displayName: 'Test' }, tenantId, userId)
+      ).rejects.toThrow(NotFoundError);
+    });
+
+    it('should update credit limit', async () => {
+      const existingPartner = createMockPartner({ creditLimit: 1000 });
+      mockRepository.findOne.mockResolvedValue(existingPartner);
+      mockRepository.save.mockResolvedValue({ ...existingPartner, creditLimit: 5000 });
+
+      await partnersService.update(
+        'partner-uuid-1',
+        { creditLimit: 5000 },
+        tenantId,
+        userId
+      );
+
+      expect(existingPartner.creditLimit).toBe(5000);
+    });
+
+    it('should set updatedBy field', async () => {
+      const existingPartner = createMockPartner();
+      mockRepository.findOne.mockResolvedValue(existingPartner);
+      mockRepository.save.mockResolvedValue(existingPartner);
+
+      await partnersService.update(
+        'partner-uuid-1',
+        { displayName: 'Updated' },
+        tenantId,
+        userId
+      );
+
+      expect(existingPartner.updatedBy).toBe(userId);
+    });
+  });
+
+  describe('delete', () => {
+    it('should soft delete partner', async () => {
+      const existingPartner = createMockPartner();
+      mockRepository.findOne.mockResolvedValue(existingPartner);
+      mockRepository.save.mockResolvedValue(existingPartner);
+
+      await partnersService.delete('partner-uuid-1', tenantId, userId);
+
+      expect(existingPartner.deletedAt).toBeInstanceOf(Date);
+      expect(existingPartner.isActive).toBe(false);
+      expect(mockRepository.save).toHaveBeenCalled();
+    });
+
+    it('should throw NotFoundError when partner not found', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+
+      await expect(
+        partnersService.delete('nonexistent-id', tenantId, userId)
+      ).rejects.toThrow(NotFoundError);
+    });
+  });
+
+  describe('findCustomers', () => {
+    it('should return only customers', async () => {
+      const mockCustomers = [createMockPartner({ partnerType: 'customer' })];
+      mockQueryBuilder.getCount.mockResolvedValue(1);
+      mockQueryBuilder.getMany.mockResolvedValue(mockCustomers);
+
+      const result = await partnersService.findCustomers(tenantId, {});
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        'partner.partnerType = :partnerType',
+        { partnerType: 'customer' }
+      );
+      expect(result.data).toHaveLength(1);
+    });
+  });
+
+  describe('findSuppliers', () => {
+    it('should return only suppliers', async () => {
+      const mockSuppliers = [createMockPartner({ partnerType: 'supplier' })];
+      mockQueryBuilder.getCount.mockResolvedValue(1);
+      mockQueryBuilder.getMany.mockResolvedValue(mockSuppliers);
+
+      const result = await partnersService.findSuppliers(tenantId, {});
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        'partner.partnerType = :partnerType',
+        { partnerType: 'supplier' }
+      );
+      expect(result.data).toHaveLength(1);
+    });
+  });
+});

src/modules/products/__tests__/products.service.test.ts

@@ -0,0 +1,302 @@
+import { jest, describe, it, expect, beforeEach } from '@jest/globals';
+import { createMockRepository, createMockProduct } from '../../../__tests__/helpers.js';
+
+// Mock dependencies before importing service
+const mockProductRepository = createMockRepository();
+const mockCategoryRepository = createMockRepository();
+
+jest.mock('../../../config/typeorm.js', () => ({
+  AppDataSource: {
+    getRepository: jest.fn((entity: any) => {
+      if (entity.name === 'Product') return mockProductRepository;
+      if (entity.name === 'ProductCategory') return mockCategoryRepository;
+      return mockProductRepository;
+    }),
+  },
+}));
+
+// Import after mocking
+import { productsService } from '../products.service.js';
+
+describe('ProductsService', () => {
+  const tenantId = 'test-tenant-uuid';
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('findAll', () => {
+    it('should return products with pagination', async () => {
+      const mockProducts = [
+        createMockProduct({ id: '1', name: 'Product A' }),
+        createMockProduct({ id: '2', name: 'Product B' }),
+      ];
+
+      mockProductRepository.findAndCount.mockResolvedValue([mockProducts, 2]);
+
+      const result = await productsService.findAll({ tenantId, limit: 50, offset: 0 });
+
+      expect(result.data).toHaveLength(2);
+      expect(result.total).toBe(2);
+    });
+
+    it('should filter by search term', async () => {
+      const mockProducts = [createMockProduct({ name: 'Test Product' })];
+      mockProductRepository.findAndCount.mockResolvedValue([mockProducts, 1]);
+
+      const result = await productsService.findAll({ tenantId, search: 'Test' });
+
+      expect(result.data).toHaveLength(1);
+      expect(mockProductRepository.findAndCount).toHaveBeenCalled();
+    });
+
+    it('should filter by category', async () => {
+      mockProductRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await productsService.findAll({ tenantId, categoryId: 'cat-uuid' });
+
+      expect(mockProductRepository.findAndCount).toHaveBeenCalled();
+    });
+
+    it('should filter by product type', async () => {
+      mockProductRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await productsService.findAll({ tenantId, productType: 'service' });
+
+      expect(mockProductRepository.findAndCount).toHaveBeenCalled();
+    });
+
+    it('should filter by sellable status', async () => {
+      mockProductRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await productsService.findAll({ tenantId, isSellable: true });
+
+      expect(mockProductRepository.findAndCount).toHaveBeenCalled();
+    });
+
+    it('should filter by purchasable status', async () => {
+      mockProductRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await productsService.findAll({ tenantId, isPurchasable: true });
+
+      expect(mockProductRepository.findAndCount).toHaveBeenCalled();
+    });
+  });
+
+  describe('findOne', () => {
+    it('should return product when found', async () => {
+      const mockProduct = createMockProduct();
+      mockProductRepository.findOne.mockResolvedValue(mockProduct);
+
+      const result = await productsService.findOne('product-uuid-1', tenantId);
+
+      expect(result).toEqual(mockProduct);
+      expect(mockProductRepository.findOne).toHaveBeenCalledWith({
+        where: {
+          id: 'product-uuid-1',
+          tenantId,
+          deletedAt: expect.anything(),
+        },
+        relations: ['category'],
+      });
+    });
+
+    it('should return null when product not found', async () => {
+      mockProductRepository.findOne.mockResolvedValue(null);
+
+      const result = await productsService.findOne('nonexistent-id', tenantId);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('findBySku', () => {
+    it('should return product by SKU', async () => {
+      const mockProduct = createMockProduct({ sku: 'PROD-001' });
+      mockProductRepository.findOne.mockResolvedValue(mockProduct);
+
+      const result = await productsService.findBySku('PROD-001', tenantId);
+
+      expect(result).toEqual(mockProduct);
+      expect(mockProductRepository.findOne).toHaveBeenCalledWith({
+        where: {
+          sku: 'PROD-001',
+          tenantId,
+          deletedAt: expect.anything(),
+        },
+        relations: ['category'],
+      });
+    });
+  });
+
+  describe('findByBarcode', () => {
+    it('should return product by barcode', async () => {
+      const mockProduct = createMockProduct({ barcode: '1234567890123' });
+      mockProductRepository.findOne.mockResolvedValue(mockProduct);
+
+      const result = await productsService.findByBarcode('1234567890123', tenantId);
+
+      expect(result).toEqual(mockProduct);
+    });
+  });
+
+  describe('create', () => {
+    const createDto = {
+      sku: 'PROD-001',
+      name: 'New Product',
+      salePrice: 100,
+      costPrice: 50,
+    };
+
+    it('should create product successfully', async () => {
+      const savedProduct = createMockProduct({ ...createDto });
+      mockProductRepository.create.mockReturnValue(savedProduct);
+      mockProductRepository.save.mockResolvedValue(savedProduct);
+
+      const result = await productsService.create(tenantId, createDto, 'user-uuid');
+
+      expect(result).toEqual(savedProduct);
+      expect(mockProductRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          tenantId,
+          sku: createDto.sku,
+          name: createDto.name,
+        })
+      );
+    });
+
+    it('should set createdBy field', async () => {
+      const savedProduct = createMockProduct();
+      mockProductRepository.create.mockReturnValue(savedProduct);
+      mockProductRepository.save.mockResolvedValue(savedProduct);
+
+      await productsService.create(tenantId, createDto, 'user-uuid');
+
+      expect(mockProductRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          createdBy: 'user-uuid',
+        })
+      );
+    });
+  });
+
+  describe('update', () => {
+    it('should update product successfully', async () => {
+      const existingProduct = createMockProduct();
+      const updatedProduct = { ...existingProduct, name: 'Updated Name' };
+      mockProductRepository.findOne.mockResolvedValue(existingProduct);
+      mockProductRepository.save.mockResolvedValue(updatedProduct);
+
+      const result = await productsService.update(
+        'product-uuid-1',
+        tenantId,
+        { name: 'Updated Name' },
+        'user-uuid'
+      );
+
+      expect(result?.name).toBe('Updated Name');
+    });
+
+    it('should return null when product not found', async () => {
+      mockProductRepository.findOne.mockResolvedValue(null);
+
+      const result = await productsService.update(
+        'nonexistent-id',
+        tenantId,
+        { name: 'Test' },
+        'user-uuid'
+      );
+
+      expect(result).toBeNull();
+    });
+
+    it('should update prices', async () => {
+      const existingProduct = createMockProduct({ salePrice: 100 });
+      mockProductRepository.findOne.mockResolvedValue(existingProduct);
+      mockProductRepository.save.mockResolvedValue({ ...existingProduct, salePrice: 150 });
+
+      await productsService.update(
+        'product-uuid-1',
+        tenantId,
+        { salePrice: 150 },
+        'user-uuid'
+      );
+
+      expect(mockProductRepository.save).toHaveBeenCalled();
+    });
+  });
+
+  describe('delete', () => {
+    it('should soft delete product', async () => {
+      mockProductRepository.softDelete.mockResolvedValue({ affected: 1 });
+
+      const result = await productsService.delete('product-uuid-1', tenantId);
+
+      expect(result).toBe(true);
+      expect(mockProductRepository.softDelete).toHaveBeenCalledWith({
+        id: 'product-uuid-1',
+        tenantId,
+      });
+    });
+
+    it('should return false when product not found', async () => {
+      mockProductRepository.softDelete.mockResolvedValue({ affected: 0 });
+
+      const result = await productsService.delete('nonexistent-id', tenantId);
+
+      expect(result).toBe(false);
+    });
+  });
+
+  describe('getSellableProducts', () => {
+    it('should return only sellable products', async () => {
+      const mockProducts = [createMockProduct({ isSellable: true })];
+      mockProductRepository.findAndCount.mockResolvedValue([mockProducts, 1]);
+
+      const result = await productsService.getSellableProducts(tenantId);
+
+      expect(result.data).toHaveLength(1);
+    });
+  });
+
+  describe('getPurchasableProducts', () => {
+    it('should return only purchasable products', async () => {
+      const mockProducts = [createMockProduct({ isPurchasable: true })];
+      mockProductRepository.findAndCount.mockResolvedValue([mockProducts, 1]);
+
+      const result = await productsService.getPurchasableProducts(tenantId);
+
+      expect(result.data).toHaveLength(1);
+    });
+  });
+
+  describe('Category operations', () => {
+    it('should find all categories', async () => {
+      const mockCategories = [{ id: '1', name: 'Category A' }];
+      mockCategoryRepository.findAndCount.mockResolvedValue([mockCategories, 1]);
+
+      const result = await productsService.findAllCategories({ tenantId });
+
+      expect(result.data).toHaveLength(1);
+    });
+
+    it('should create category', async () => {
+      const categoryDto = { code: 'CAT-001', name: 'New Category' };
+      const savedCategory = { id: '1', ...categoryDto };
+      mockCategoryRepository.create.mockReturnValue(savedCategory);
+      mockCategoryRepository.save.mockResolvedValue(savedCategory);
+
+      const result = await productsService.createCategory(tenantId, categoryDto);
+
+      expect(result).toEqual(savedCategory);
+    });
+
+    it('should delete category', async () => {
+      mockCategoryRepository.softDelete.mockResolvedValue({ affected: 1 });
+
+      const result = await productsService.deleteCategory('cat-uuid', tenantId);
+
+      expect(result).toBe(true);
+    });
+  });
+});

src/modules/warehouses/__tests__/warehouses.service.test.ts

@@ -0,0 +1,345 @@
+import { jest, describe, it, expect, beforeEach } from '@jest/globals';
+import { createMockRepository, createMockQueryBuilder, createMockWarehouse } from '../../../__tests__/helpers.js';
+
+// Mock dependencies before importing service
+const mockWarehouseRepository = createMockRepository();
+const mockLocationRepository = createMockRepository();
+const mockQueryBuilder = createMockQueryBuilder();
+
+jest.mock('../../../config/typeorm.js', () => ({
+  AppDataSource: {
+    getRepository: jest.fn((entity: any) => {
+      if (entity.name === 'Warehouse') return mockWarehouseRepository;
+      if (entity.name === 'WarehouseLocation') return mockLocationRepository;
+      return mockWarehouseRepository;
+    }),
+  },
+}));
+
+// Import after mocking
+import { warehousesService } from '../warehouses.service.js';
+
+describe('WarehousesService', () => {
+  const tenantId = 'test-tenant-uuid';
+  const userId = 'test-user-uuid';
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    mockLocationRepository.createQueryBuilder.mockReturnValue(mockQueryBuilder);
+  });
+
+  describe('findAll', () => {
+    it('should return warehouses with pagination', async () => {
+      const mockWarehouses = [
+        createMockWarehouse({ id: '1', name: 'Warehouse A' }),
+        createMockWarehouse({ id: '2', name: 'Warehouse B' }),
+      ];
+
+      mockWarehouseRepository.findAndCount.mockResolvedValue([mockWarehouses, 2]);
+
+      const result = await warehousesService.findAll({ tenantId, limit: 50, offset: 0 });
+
+      expect(result.data).toHaveLength(2);
+      expect(result.total).toBe(2);
+    });
+
+    it('should filter by search term', async () => {
+      const mockWarehouses = [createMockWarehouse({ name: 'Main Warehouse' })];
+      mockWarehouseRepository.findAndCount.mockResolvedValue([mockWarehouses, 1]);
+
+      const result = await warehousesService.findAll({ tenantId, search: 'Main' });
+
+      expect(result.data).toHaveLength(1);
+    });
+
+    it('should filter by active status', async () => {
+      mockWarehouseRepository.findAndCount.mockResolvedValue([[], 0]);
+
+      await warehousesService.findAll({ tenantId, isActive: true });
+
+      expect(mockWarehouseRepository.findAndCount).toHaveBeenCalled();
+    });
+  });
+
+  describe('findOne', () => {
+    it('should return warehouse when found', async () => {
+      const mockWarehouse = createMockWarehouse();
+      mockWarehouseRepository.findOne.mockResolvedValue(mockWarehouse);
+
+      const result = await warehousesService.findOne('warehouse-uuid-1', tenantId);
+
+      expect(result).toEqual(mockWarehouse);
+      expect(mockWarehouseRepository.findOne).toHaveBeenCalledWith({
+        where: {
+          id: 'warehouse-uuid-1',
+          tenantId,
+          deletedAt: expect.anything(),
+        },
+      });
+    });
+
+    it('should return null when warehouse not found', async () => {
+      mockWarehouseRepository.findOne.mockResolvedValue(null);
+
+      const result = await warehousesService.findOne('nonexistent-id', tenantId);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('findByCode', () => {
+    it('should return warehouse by code', async () => {
+      const mockWarehouse = createMockWarehouse({ code: 'WH-001' });
+      mockWarehouseRepository.findOne.mockResolvedValue(mockWarehouse);
+
+      const result = await warehousesService.findByCode('WH-001', tenantId);
+
+      expect(result).toEqual(mockWarehouse);
+      expect(mockWarehouseRepository.findOne).toHaveBeenCalledWith({
+        where: {
+          code: 'WH-001',
+          tenantId,
+          deletedAt: expect.anything(),
+        },
+      });
+    });
+  });
+
+  describe('getDefault', () => {
+    it('should return default warehouse', async () => {
+      const mockWarehouse = createMockWarehouse({ isDefault: true });
+      mockWarehouseRepository.findOne.mockResolvedValue(mockWarehouse);
+
+      const result = await warehousesService.getDefault(tenantId);
+
+      expect(result?.isDefault).toBe(true);
+    });
+
+    it('should return null when no default warehouse exists', async () => {
+      mockWarehouseRepository.findOne.mockResolvedValue(null);
+
+      const result = await warehousesService.getDefault(tenantId);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('getActive', () => {
+    it('should return only active warehouses', async () => {
+      const mockWarehouses = [
+        createMockWarehouse({ isActive: true }),
+        createMockWarehouse({ isActive: true }),
+      ];
+      mockWarehouseRepository.find.mockResolvedValue(mockWarehouses);
+
+      const result = await warehousesService.getActive(tenantId);
+
+      expect(result).toHaveLength(2);
+    });
+  });
+
+  describe('create', () => {
+    const createDto = {
+      code: 'WH-001',
+      name: 'New Warehouse',
+      address: '123 Main St',
+      city: 'Test City',
+    };
+
+    it('should create warehouse successfully', async () => {
+      const savedWarehouse = createMockWarehouse({ ...createDto });
+      mockWarehouseRepository.create.mockReturnValue(savedWarehouse);
+      mockWarehouseRepository.save.mockResolvedValue(savedWarehouse);
+
+      const result = await warehousesService.create(tenantId, createDto, userId);
+
+      expect(result).toEqual(savedWarehouse);
+      expect(mockWarehouseRepository.create).toHaveBeenCalledWith(
+        expect.objectContaining({
+          tenantId,
+          code: createDto.code,
+          name: createDto.name,
+        })
+      );
+    });
+
+    it('should unset other defaults when creating default warehouse', async () => {
+      const createDtoWithDefault = { ...createDto, isDefault: true };
+      mockWarehouseRepository.update.mockResolvedValue({ affected: 1 });
+      mockWarehouseRepository.create.mockReturnValue(createMockWarehouse(createDtoWithDefault));
+      mockWarehouseRepository.save.mockResolvedValue(createMockWarehouse(createDtoWithDefault));
+
+      await warehousesService.create(tenantId, createDtoWithDefault, userId);
+
+      expect(mockWarehouseRepository.update).toHaveBeenCalledWith(
+        { tenantId, isDefault: true },
+        { isDefault: false }
+      );
+    });
+  });
+
+  describe('update', () => {
+    it('should update warehouse successfully', async () => {
+      const existingWarehouse = createMockWarehouse();
+      mockWarehouseRepository.findOne.mockResolvedValue(existingWarehouse);
+      mockWarehouseRepository.save.mockResolvedValue({ ...existingWarehouse, name: 'Updated Name' });
+
+      const result = await warehousesService.update(
+        'warehouse-uuid-1',
+        tenantId,
+        { name: 'Updated Name' },
+        userId
+      );
+
+      expect(result?.name).toBe('Updated Name');
+    });
+
+    it('should return null when warehouse not found', async () => {
+      mockWarehouseRepository.findOne.mockResolvedValue(null);
+
+      const result = await warehousesService.update(
+        'nonexistent-id',
+        tenantId,
+        { name: 'Test' },
+        userId
+      );
+
+      expect(result).toBeNull();
+    });
+
+    it('should unset other defaults when setting as default', async () => {
+      const existingWarehouse = createMockWarehouse({ isDefault: false });
+      mockWarehouseRepository.findOne.mockResolvedValue(existingWarehouse);
+      mockWarehouseRepository.update.mockResolvedValue({ affected: 1 });
+      mockWarehouseRepository.save.mockResolvedValue({ ...existingWarehouse, isDefault: true });
+
+      await warehousesService.update(
+        'warehouse-uuid-1',
+        tenantId,
+        { isDefault: true },
+        userId
+      );
+
+      expect(mockWarehouseRepository.update).toHaveBeenCalledWith(
+        { tenantId, isDefault: true },
+        { isDefault: false }
+      );
+    });
+  });
+
+  describe('delete', () => {
+    it('should soft delete warehouse', async () => {
+      mockWarehouseRepository.softDelete.mockResolvedValue({ affected: 1 });
+
+      const result = await warehousesService.delete('warehouse-uuid-1', tenantId);
+
+      expect(result).toBe(true);
+    });
+
+    it('should return false when warehouse not found', async () => {
+      mockWarehouseRepository.softDelete.mockResolvedValue({ affected: 0 });
+
+      const result = await warehousesService.delete('nonexistent-id', tenantId);
+
+      expect(result).toBe(false);
+    });
+  });
+
+  describe('Location operations', () => {
+    const createLocationDto = {
+      warehouseId: 'warehouse-uuid-1',
+      code: 'LOC-001',
+      name: 'Location A',
+      locationType: 'shelf' as const,
+    };
+
+    beforeEach(() => {
+      mockQueryBuilder.getOne.mockResolvedValue(null);
+      mockQueryBuilder.getMany.mockResolvedValue([]);
+      mockQueryBuilder.getManyAndCount.mockResolvedValue([[], 0]);
+    });
+
+    it('should find all locations with tenant filtering via join', async () => {
+      mockQueryBuilder.getManyAndCount.mockResolvedValue([[], 0]);
+
+      await warehousesService.findAllLocations({ tenantId, limit: 50, offset: 0 });
+
+      expect(mockQueryBuilder.where).toHaveBeenCalledWith(
+        'warehouse.tenantId = :tenantId',
+        { tenantId }
+      );
+    });
+
+    it('should filter locations by warehouse', async () => {
+      mockQueryBuilder.getManyAndCount.mockResolvedValue([[], 0]);
+
+      await warehousesService.findAllLocations({
+        tenantId,
+        warehouseId: 'warehouse-uuid',
+      });
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        'location.warehouseId = :warehouseId',
+        { warehouseId: 'warehouse-uuid' }
+      );
+    });
+
+    it('should filter locations by type', async () => {
+      mockQueryBuilder.getManyAndCount.mockResolvedValue([[], 0]);
+
+      await warehousesService.findAllLocations({
+        tenantId,
+        locationType: 'shelf',
+      });
+
+      expect(mockQueryBuilder.andWhere).toHaveBeenCalledWith(
+        'location.locationType = :locationType',
+        { locationType: 'shelf' }
+      );
+    });
+
+    it('should create location', async () => {
+      const savedLocation = { id: '1', ...createLocationDto };
+      mockLocationRepository.create.mockReturnValue(savedLocation);
+      mockLocationRepository.save.mockResolvedValue(savedLocation);
+
+      const result = await warehousesService.createLocation(tenantId, createLocationDto, userId);
+
+      expect(result).toEqual(savedLocation);
+    });
+
+    it('should update location', async () => {
+      const existingLocation = { id: '1', ...createLocationDto };
+      mockQueryBuilder.getOne.mockResolvedValue(existingLocation);
+      mockLocationRepository.save.mockResolvedValue({ ...existingLocation, name: 'Updated Location' });
+
+      const result = await warehousesService.updateLocation(
+        'location-uuid',
+        tenantId,
+        { name: 'Updated Location' },
+        userId
+      );
+
+      expect(result?.name).toBe('Updated Location');
+    });
+
+    it('should delete location', async () => {
+      const existingLocation = { id: '1', ...createLocationDto };
+      mockQueryBuilder.getOne.mockResolvedValue(existingLocation);
+      mockLocationRepository.softDelete.mockResolvedValue({ affected: 1 });
+
+      const result = await warehousesService.deleteLocation('location-uuid', tenantId);
+
+      expect(result).toBe(true);
+    });
+
+    it('should get locations by warehouse', async () => {
+      const mockLocations = [{ id: '1', code: 'LOC-001' }];
+      mockQueryBuilder.getMany.mockResolvedValue(mockLocations);
+
+      const result = await warehousesService.getLocationsByWarehouse('warehouse-uuid', tenantId);
+
+      expect(result).toHaveLength(1);
+    });
+  });
+});