refactor: migrate credit note and vendor credit services to nestjs

packages/server-nest/src/modules/VendorCredit/queries/GetVendorCredit.service.ts

@@ -0,0 +1,42 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { VendorCreditTransformer } from './VendorCreditTransformer';
+import { ERRORS } from '../constants';
+import { TransformerInjectable } from '@/modules/Transformer/TransformerInjectable.service';
+import { VendorCredit } from '../models/VendorCredit';
+import { ServiceError } from '@/modules/Items/ServiceError';
+import { Knex } from 'knex';
+
+@Injectable()
+export default class GetVendorCreditService {
+  constructor(
+    @Inject(VendorCredit.name)
+    private readonly vendorCreditModel: typeof VendorCredit,
+    private readonly transformer: TransformerInjectable,
+  ) {}
+
+  /**
+   * Retrieve the given vendor credit.
+   * @param {number} vendorCreditId - Vendor credit id.
+   */
+  public async getVendorCredit(
+    vendorCreditId: number,
+    trx?: Knex.Transaction,
+  ) {
+    // Retrieve the vendor credit model graph.
+    const vendorCredit = await this.vendorCreditModel
+      .query()
+      .findById(vendorCreditId)
+      .withGraphFetched('entries.item')
+      .withGraphFetched('vendor')
+      .withGraphFetched('branch') 
+      .withGraphFetched('attachments');
+
+    if (!vendorCredit) {
+      throw new ServiceError(ERRORS.VENDOR_CREDIT_NOT_FOUND);
+    }
+    return this.transformer.transform(
+      vendorCredit,
+      new VendorCreditTransformer()
+    );
+  }
+}