feat(nestjs): migrate to NestJS

packages/server/src/modules/Expenses/commands/DeleteExpense.service.ts

@@ -0,0 +1,79 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import { CommandExpenseValidator } from './CommandExpenseValidator.service';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { Expense } from '../models/Expense.model';
+import { ExpenseCategory } from '../models/ExpenseCategory.model';
+import { events } from '@/common/events/events';
+import {
+  IExpenseEventDeletePayload,
+  IExpenseDeletingPayload,
+} from '../interfaces/Expenses.interface';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class DeleteExpense {
+  /**
+   * @param {EventEmitter2} eventEmitter - Event emitter.
+   * @param {UnitOfWork} uow - Unit of work.
+   * @param {CommandExpenseValidator} validator - Command expense validator.
+   * @param {TenantModelProxy<typeof Expense>} expenseModel - Expense model.
+   * @param {TenantModelProxy<typeof ExpenseCategory>} expenseCategoryModel - Expense category model.
+   */
+  constructor(
+    private readonly eventEmitter: EventEmitter2,
+    private readonly uow: UnitOfWork,
+    private readonly validator: CommandExpenseValidator,
+
+    @Inject(Expense.name)
+    private expenseModel: TenantModelProxy<typeof Expense>,
+
+    @Inject(ExpenseCategory.name)
+    private expenseCategoryModel: TenantModelProxy<typeof ExpenseCategory>,
+  ) {}
+
+  /**
+   * Deletes the given expense.
+   * @param {number} expenseId
+   * @param {ISystemUser} authorizedUser
+   */
+  public async deleteExpense(expenseId: number): Promise<void> {
+    // Retrieves the expense transaction with associated entries or
+    // throw not found error.
+    const oldExpense = await this.expenseModel()
+      .query()
+      .findById(expenseId)
+      .withGraphFetched('categories')
+      .throwIfNotFound();
+
+    // Validates the expense has no associated landed cost.
+    await this.validator.validateNoAssociatedLandedCost(expenseId);
+
+    // Deletes expense transactions with associated transactions under
+    // unit-of-work envirement.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onExpenseDeleting` event.
+      await this.eventEmitter.emitAsync(events.expenses.onDeleting, {
+        trx,
+        oldExpense,
+      } as IExpenseDeletingPayload);
+
+      // Deletes expense associated entries.
+      await this.expenseCategoryModel()
+        .query(trx)
+        .where('expenseId', expenseId)
+        .delete();
+
+      // Deletes expense transactions.
+      await this.expenseModel().query(trx).findById(expenseId).delete();
+
+      // Triggers `onExpenseDeleted` event.
+      await this.eventEmitter.emitAsync(events.expenses.onDeleted, {
+        expenseId,
+        oldExpense,
+        trx,
+      } as IExpenseEventDeletePayload);
+    });
+  }
+}