refactor(nestjs): currencies module

packages/server/src/modules/Currencies/commands/CreateCurrency.service.ts

@@ -0,0 +1,45 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { TenantModelProxy } from '../../System/models/TenantBaseModel';
+import { Currency } from '../models/Currency.model';
+import { ServiceError } from '@/modules/Items/ServiceError';
+import { ERRORS } from '../Currencies.constants';
+import { CreateCurrencyDto } from '../dtos/CreateCurrency.dto';
+
+@Injectable()
+export class CreateCurrencyService {
+  constructor(
+    @Inject(Currency.name)
+    private readonly currencyModel: TenantModelProxy<typeof Currency>,
+  ) {}
+
+  async createCurrency(currencyDTO: CreateCurrencyDto) {
+    // Validate currency code uniquiness.
+    await this.validateCurrencyCodeUniquiness(currencyDTO.currencyCode);
+    await this.currencyModel()
+      .query()
+      .insert({ ...currencyDTO });
+  }
+
+  /**
+   * Retrieve currency by given currency code or throw not found error.
+   * @param {string} currencyCode
+   * @param {number} currencyId
+   */
+  private async validateCurrencyCodeUniquiness(
+    currencyCode: string,
+    currencyId?: number,
+  ) {
+    const foundCurrency = await this.currencyModel()
+      .query()
+      .onBuild((query) => {
+        query.findOne('currency_code', currencyCode);
+
+        if (currencyId) {
+          query.whereNot('id', currencyId);
+        }
+      });
+    if (foundCurrency) {
+      throw new ServiceError(ERRORS.CURRENCY_CODE_EXISTS);
+    }
+  }
+}