public void ConvertByAlexTest_ToUsd(decimal rate, decimal amount, decimal expectedResult, Currency currency) { //Preparation var exchangeRateToUsdCurrent = new ExchangeRateToUsdCurrent() { ExchRate = rate }; _exchangeRateToUsdCurrentRepositoryMock .Setup(x => x.GetExchangeRate(currency, TypeOfExchange.Sell)) .Returns(exchangeRateToUsdCurrent); //Act var actualResult = _currencyService.ConvertByAlex(amount, currency); //Assert Assert.AreEqual(expectedResult, actualResult); }