public async void Test_Caching()
{
// Arrange
var mockInnerFactory = new Mock <IFilterExpressionFactory>();
mockInnerFactory.Setup(f => f.GetExpressionAsync(It.IsAny <string>()))
.Returns(Task.FromResult <IFilterExpression>(new ConstantExpression("Foo")));
var cache = new MemoryCache(typeof(CachingFilterExpressionFactory).Name);
var factory = new CachingFilterExpressionFactory(mockInnerFactory.Object, cache);
bool flag = false;
var evt = new AutoResetEvent(false);
factory.DefaultPolicy = new CacheItemPolicy()
{
SlidingExpiration = TimeSpan.FromMilliseconds(1),
RemovedCallback = arguments =>
{
flag = true;
evt.Set();
}
};
// Act
var d1 = DateTimeOffset.Now;
await factory.GetExpressionAsync("foo");
evt.WaitOne(cache.PollingInterval + cache.PollingInterval);
var timeSpan = DateTimeOffset.Now - d1;
Debug.WriteLine("CacheItem expired after {0}ms", timeSpan.Milliseconds);
// Assert
Assert.That(flag, Is.True);
}
public async void Test_that_factory_only_called_once()
{
// Arrange
var mockInnerFactory = new Mock <IFilterExpressionFactory>();
mockInnerFactory.Setup(f => f.GetExpressionAsync(It.IsAny <string>()))
.Returns(Task.FromResult <IFilterExpression>(new ConstantExpression("Foo")));
var cache = new MemoryCache(typeof(CachingFilterExpressionFactory).Name);
var factory = new CachingFilterExpressionFactory(mockInnerFactory.Object, cache);
// Act
var exp1 = await factory.GetExpressionAsync("Foo = 1");
var exp2 = await factory.GetExpressionAsync("Foo = 1");
// Assert
Assert.That(exp1, Is.SameAs(exp2));
mockInnerFactory.Verify(f => f.GetExpressionAsync("Foo = 1"), Times.Exactly(1));
}