Add portfolio summary tests

apps/api/src/app/portfolio/portfolio.service.spec.ts

@@ -350,7 +350,8 @@ describe('PortfolioService', () => {
       ).getSummary(args);
     };
 
-    const portfolioCalculator = {
+    function createPortfolioCalculator() {
+      return {
         getDividendInBaseCurrency: jest.fn().mockResolvedValue(new Big(0)),
         getFeesInBaseCurrency: jest.fn().mockResolvedValue(new Big(0)),
         getInterestInBaseCurrency: jest.fn().mockResolvedValue(new Big(0)),
@@ -363,6 +364,7 @@ describe('PortfolioService', () => {
         }),
         getStartDate: jest.fn().mockReturnValue(parseDate('2024-01-01'))
       } as unknown as PortfolioCalculator;
+    }
 
     beforeEach(() => {
       jest
@@ -399,6 +401,8 @@ describe('PortfolioService', () => {
         balanceInBaseCurrency: 1000
       });
 
+      const portfolioCalculator = createPortfolioCalculator();
+
       const summary = await getSummary({
         portfolioCalculator,
         balanceInBaseCurrency: 1000,