public void Given_CurrencyAndDateRange_When_GetHistoricalAsyncInvoked_Then_resultWithHistoricalExchangeRatesRetrived() { var currency = "EUR"; DateTime beginDate = new DateTime(2017, 1, 1), endDate = new DateTime(2017, 12, 31); var actionResult = _serviceUnderTest.GetHistoricalAsync(currency, beginDate, endDate).Result; Assert.IsNotNull(actionResult); Assert.IsTrue(actionResult.All(x => x.To == currency)); Assert.IsTrue(actionResult.All(x => x.Date >= beginDate && x.Date <= endDate)); }