Add customers management module with database schema and validation

- Introduced `CustomersModule` to manage customer data, including read and write controllers.
- Created database migrations for the `customers` and `customer_contacts` tables, including constraints and unique indexes.
- Implemented validation for customer fields such as name, code, and address with corresponding utility functions.
- Developed service and repository layers for handling customer data operations.
- Added unit tests for the customers service, repository, and controllers to ensure functionality and correctness.
- Updated application module to include the new `CustomersModule` for better organization.

src/modules/configuration/customers/customers-write.controller.spec.ts

@@ -0,0 +1,105 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { CustomersWriteController } from './customers-write.controller';
+import { CustomersService } from './customers.service';
+
+const createDto = {
+  code: 'CUST_01',
+  name: 'Acme Corp',
+  phone: '+6281234567890',
+  address: 'Jl Sudirman No 1',
+};
+
+describe('CustomersWriteController', () => {
+  let controller: CustomersWriteController;
+  const service = {
+    create: jest.fn(),
+    update: jest.fn(),
+    updateStatus: jest.fn(),
+    delete: jest.fn(),
+    bulkDelete: jest.fn(),
+    bulkUpdateStatus: jest.fn(),
+    importCsv: jest.fn(),
+    addContact: jest.fn(),
+    updateContact: jest.fn(),
+    deleteContact: jest.fn(),
+  };
+
+  beforeEach(async () => {
+    jest.clearAllMocks();
+    const moduleRef: TestingModule = await Test.createTestingModule({
+      controllers: [CustomersWriteController],
+      providers: [{ provide: CustomersService, useValue: service }],
+    }).compile();
+    controller = moduleRef.get(CustomersWriteController);
+  });
+
+  it('create passes dto fields and user id', async () => {
+    service.create.mockResolvedValue({ id: 'cu-1' });
+    await controller.create(createDto, 'user-1');
+    expect(service.create).toHaveBeenCalledWith({
+      ...createDto,
+      userId: 'user-1',
+    });
+  });
+
+  it('update, updateStatus, and delete delegate', async () => {
+    service.update.mockResolvedValue({ id: 'cu-1' });
+    service.updateStatus.mockResolvedValue({ id: 'cu-1' });
+    service.delete.mockResolvedValue(undefined);
+    await controller.update('cu-1', { name: 'Acme Corp' }, 'user-1');
+    await controller.updateStatus('cu-1', { status: 'active' }, 'user-1');
+    await controller.delete('cu-1');
+    expect(service.updateStatus).toHaveBeenCalledWith(
+      'cu-1',
+      'active',
+      'user-1',
+    );
+    expect(service.delete).toHaveBeenCalledWith('cu-1');
+  });
+
+  it('nested contact routes delegate', async () => {
+    service.addContact.mockResolvedValue({ id: 'cu-1' });
+    service.updateContact.mockResolvedValue({ id: 'cu-1' });
+    service.deleteContact.mockResolvedValue(undefined);
+    await controller.addContact('cu-1', { name: 'Ada Lovelace' }, 'user-1');
+    await controller.updateContact(
+      'cu-1',
+      'ct-1',
+      { jobTitle: 'Buyer' },
+      'user-1',
+    );
+    await controller.deleteContact('cu-1', 'ct-1');
+    expect(service.addContact).toHaveBeenCalledWith(
+      'cu-1',
+      { name: 'Ada Lovelace' },
+      'user-1',
+    );
+    expect(service.updateContact).toHaveBeenCalledWith('cu-1', 'ct-1', {
+      jobTitle: 'Buyer',
+      userId: 'user-1',
+    });
+    expect(service.deleteContact).toHaveBeenCalledWith('cu-1', 'ct-1');
+  });
+
+  it('bulk and import delegate', async () => {
+    service.bulkDelete.mockResolvedValue({ deleted: 1 });
+    service.bulkUpdateStatus.mockResolvedValue({ updated: 1 });
+    service.importCsv.mockResolvedValue({ imported: 1 });
+    await controller.bulkDelete({ ids: ['cu-1'] });
+    await controller.bulkStatus(
+      { ids: ['cu-1'], status: 'archived' },
+      'user-1',
+    );
+    await controller.importCsv(
+      { buffer: Buffer.from('code,name\nCUST_01,Acme') },
+      'user-1',
+    );
+    expect(service.importCsv).toHaveBeenCalled();
+  });
+
+  it('importCsv uses empty string when file is missing', async () => {
+    service.importCsv.mockResolvedValue({ imported: 0 });
+    await controller.importCsv(undefined, 'user-1');
+    expect(service.importCsv).toHaveBeenCalledWith('', 'user-1');
+  });
+});