refactor xmr rate module to exchange rate module for multi crypto support

backend/src/modules/payment/services/InvoiceService.spec.ts

@@ -2,7 +2,7 @@ import { Logger, ServiceUnavailableException } from '@nestjs/common';
 import type { ConfigService } from '@nestjs/config';
 import type { Repository } from 'typeorm';
 import type { MoneroWalletRpcClient } from '../../moneroWallet/services/MoneroWalletRpcClient';
-import type { XmrRateService } from '../../xmrRate/services/XmrRateService';
+import type { ExchangeRateService } from '../../exchangeRate/services/ExchangeRateService';
 import { Invoice } from '../entities/Invoice';
 import { InvoiceReason } from '../types/InvoiceReason';
 import { PaymentMethod } from '../types/PaymentMethod';
@@ -22,8 +22,8 @@ describe('InvoiceService', () => {
     let walletRpcClient: {
         createAddress: jest.Mock;
     };
-    let xmrRateService: {
-        getLiveFiatPerXmr: jest.Mock;
+    let exchangeRateService: {
+        getLiveFiatPerCrypto: jest.Mock;
     };
     let errorLogSpy: jest.SpiedFunction<typeof Logger.prototype.error>;
 
@@ -60,15 +60,15 @@ describe('InvoiceService', () => {
             })
         };
 
-        xmrRateService = {
-            getLiveFiatPerXmr: jest.fn().mockReturnValue(150)
+        exchangeRateService = {
+            getLiveFiatPerCrypto: jest.fn().mockReturnValue(150)
         };
 
         service = new InvoiceService(
             invoiceRepo as unknown as Repository<Invoice>,
             configService as unknown as ConfigService,
             walletRpcClient as unknown as MoneroWalletRpcClient,
-            xmrRateService as unknown as XmrRateService
+            exchangeRateService as unknown as ExchangeRateService
         );
     });
 
@@ -85,7 +85,7 @@ describe('InvoiceService', () => {
         });
 
     it('throws when the live XMR rate is unavailable for checkout invoices', async () => {
-        xmrRateService.getLiveFiatPerXmr.mockReturnValue(null);
+        exchangeRateService.getLiveFiatPerCrypto.mockReturnValue(null);
 
         await expect(issueCheckoutInvoice()).rejects.toThrow(
             new ServiceUnavailableException("We can't show a price right now. Please try again in a few minutes.")
@@ -169,7 +169,7 @@ describe('InvoiceService', () => {
     });
 
     it('uses shipping-specific messages and address labels for shipping invoices', async () => {
-        xmrRateService.getLiveFiatPerXmr.mockReturnValue(null);
+        exchangeRateService.getLiveFiatPerCrypto.mockReturnValue(null);
 
         await expect(
             service.issueInvoice({
@@ -184,7 +184,7 @@ describe('InvoiceService', () => {
             )
         );
 
-        xmrRateService.getLiveFiatPerXmr.mockReturnValue(150);
+        exchangeRateService.getLiveFiatPerCrypto.mockReturnValue(150);
         walletRpcClient.createAddress.mockRejectedValue(new Error('rpc down'));
 
         await expect(