feat(nestjs): migrate to NestJS

packages/server/src/modules/Customers/commands/CreateCustomer.service.ts

@@ -0,0 +1,68 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import { CreateEditCustomerDTO } from './CreateEditCustomerDTO.service';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { Customer } from '../models/Customer';
+import { events } from '@/common/events/events';
+import {
+  ICustomerEventCreatedPayload,
+  ICustomerEventCreatingPayload,
+} from '../types/Customers.types';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import { CreateCustomerDto } from '../dtos/CreateCustomer.dto';
+
+@Injectable()
+export class CreateCustomer {
+  /**
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {CreateEditCustomerDTO} customerDTO - Customer DTO.
+   * @param {typeof Customer} customerModel - Customer model.
+   */
+  constructor(
+    private readonly uow: UnitOfWork,
+    private readonly eventPublisher: EventEmitter2,
+    private readonly customerDTO: CreateEditCustomerDTO,
+
+    @Inject(Customer.name)
+    private readonly customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Creates a new customer.
+   * @param  {ICustomerNewDTO} customerDTO
+   * @return {Promise<ICustomer>}
+   */
+  public async createCustomer(
+    customerDTO: CreateCustomerDto,
+    trx?: Knex.Transaction,
+  ): Promise<Customer> {
+    // Transformes the customer DTO to customer object.
+    const customerObj = await this.customerDTO.transformCreateDTO(customerDTO);
+
+    // Creates a new customer under unit-of-work envirement.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onCustomerCreating` event.
+      await this.eventPublisher.emitAsync(events.customers.onCreating, {
+        customerDTO,
+        trx,
+      } as ICustomerEventCreatingPayload);
+
+      // Creates a new contact as customer.
+      const customer = await this.customerModel()
+        .query(trx)
+        .insertAndFetch({
+          ...customerObj,
+        });
+      // Triggers `onCustomerCreated` event.
+      await this.eventPublisher.emitAsync(events.customers.onCreated, {
+        customer,
+        customerId: customer.id,
+        trx,
+      } as ICustomerEventCreatedPayload);
+
+      return customer;
+    }, trx);
+  }
+}