public void Fetcher_BeginFetch_StatusFetchingIfNoResultYet()
{
var fetcher = new Fetcher <int>(Returns1Eventually);
fetcher.BeginFetch();
Assert.AreEqual(FetchStatus.Fetching, fetcher.Status);
}
public void Fetcher_BeginFetch_KeepsTryingWhenExceptionThrownByDefault()
{
var sw = new Stopwatch();
var timeoutMs = 5;
var fetcher = new Fetcher <int>(getValue: AlwaysThrowsDivideByZeroException);
fetcher.Fetched += EventShouldNotBeRaised;
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(FetchStatus.Fetching, fetcher.Status);
Assert.Throws <InvalidOperationException>(() => { var x = fetcher.Result; });
}
public void Fetcher_BeginFetch_StatusErrorIfUnfilteredExceptionThrown()
{
var sw = new Stopwatch();
var timeoutMs = 5;
var fetcher = new Fetcher <int>(
getValue: AlwaysThrowsNullReferenceException,
exceptionFilter: FilterAllButNullReferenceExceptions);
fetcher.Fetched += EventShouldNotBeRaised;
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(FetchStatus.Error, fetcher.Status);
}
public void Fetcher_BeginFetch_ValueFilterPreventsValuesThatReturnFalseFromBeingFound()
{
var sw = new Stopwatch();
var timeoutMs = 5;
var fetcher = new Fetcher <int>(
getValue: AlwaysReturns1,
valueFilter: FilterEvenValues);
fetcher.Fetched += EventShouldNotBeRaised;
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(FetchStatus.Fetching, fetcher.Status);
Assert.Throws <InvalidOperationException>(() => { var x = fetcher.Result; });
}
public void Fetcher_BeginFetch_ExceptionFilterThrowsIfExceptionReturnsFalse()
{
var sw = new Stopwatch();
var timeoutMs = 5;
var fetcher = new Fetcher <int>(
getValue: AlwaysThrowsNullReferenceException,
exceptionFilter: FilterAllButNullReferenceExceptions);
fetcher.Fetched += (sender, e) => { Assert.Fail("Event should not be raised."); };
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(FetchStatus.Error, fetcher.Status);
Assert.Throws <InvalidOperationException>(() => { var x = fetcher.Result; });
}
public void Fetcher_BeginFetch_PublishesAvailableResultsQuickly()
{
var sw = new Stopwatch();
var timeoutMs = 5;
//Will store published result
int?result = null;
//Create a fetcher that fetches the constant 1
var fetcher = new Fetcher <int>(getValue: AlwaysReturns1);
fetcher.Fetched += (sender, e) => { result = fetcher.Result; };
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs && result == null)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(1, result);
}
public void Fetcher_BeginFetch_PublishesDelayedResultsEventually()
{
var sw = new Stopwatch();
var timeoutMs = 1100;
//Will store published result
int?result = null;
//Create a fetcher that fetches the constant 1
var fetcher = new Fetcher <int>(getValue: Returns1Eventually);
fetcher.Fetched += (sender, e) => { result = fetcher.Result; };
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs && result == null)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(1, result);
Assert.AreEqual(FetchStatus.Found, fetcher.Status);
}
public void Fetcher_BeginFetch_ValueFilterAllowsValuesThatReturnTrueToBeFound()
{
var sw = new Stopwatch();
var timeoutMs = 5;
//Will store published result
int?result = null;
//Create a fetcher that fetches the constant 1
var fetcher = new Fetcher <int>(getValue: AlwaysReturns2);
fetcher.Fetched += (sender, e) => { result = fetcher.Result; };
sw.Start();
fetcher.BeginFetch();
while (sw.ElapsedMilliseconds < timeoutMs && result == null)
{
//Loop until event is fired and handled, or timeout is up.
}
Assert.AreEqual(2, result);
Assert.AreEqual(FetchStatus.Found, fetcher.Status);
}