public void GetExchangeRateOnceWillReturnRateFromInnerCurrency(decimal expectedExchangeRate, string currencyCode, [Frozen] Mock <Currency> innerCurrencyStub, CachingCurrency sut)
{
// Fixture setup
innerCurrencyStub.Setup(c => c.GetExchangeRateFor(currencyCode)).Returns(expectedExchangeRate);
// Exercise system
var result = sut.GetExchangeRateFor(currencyCode);
// Verify outcome
Assert.Equal <decimal>(expectedExchangeRate, result);
// Teardown (implicit)
}
public void InnerCurrencyIsInvokedAgainWhenCacheExpires()
{
// Fixture setup
var currencyCode = "CHF";
var cacheTimeout = TimeSpan.FromHours(1);
var startTime = new DateTime(2009, 8, 29);
var timeProviderStub = new Mock <TimeProvider>();
timeProviderStub
.SetupGet(tp => tp.UtcNow)
.Returns(startTime);
TimeProvider.Current = timeProviderStub.Object;
var innerCurrencyMock = new Mock <Currency>();
innerCurrencyMock
.Setup(c => c.GetExchangeRateFor(currencyCode))
.Returns(4.911m)
.Verifiable();
var sut =
new CachingCurrency(innerCurrencyMock.Object,
cacheTimeout);
sut.GetExchangeRateFor(currencyCode);
sut.GetExchangeRateFor(currencyCode);
sut.GetExchangeRateFor(currencyCode);
timeProviderStub
.SetupGet(tp => tp.UtcNow)
.Returns(startTime + cacheTimeout);
// Exercise system
sut.GetExchangeRateFor(currencyCode);
// Verify outcome
innerCurrencyMock.Verify(
c => c.GetExchangeRateFor(currencyCode),
Times.Exactly(2));
// Teardown (implicit)
}
