public async Task FailedCallQuaranteensUrl_TwoUris()
{
var callCount = 0;
var webStore = new TestWebStore(2, new BaseUris(new[] { "http://localhost", "http://localhost2" }, MultiUriSelectionStrategyFactory.Default), "test user agent");
webStore.WebClientMock
.Setup(x => x.DownloadStringAsync(It.IsAny <Uri>(), It.IsAny <CancellationToken>()))
.Returns <Uri, CancellationToken>((uri, ct) =>
{
callCount++;
TaskCompletionSource <string> tcs = new TaskCompletionSource <string>();
if (uri.Host == "localhost")
{
tcs.TrySetException(new WebException("Server not found", WebExceptionStatus.NameResolutionFailure));
}
else if (uri.Host == "localhost2")
{
tcs.TrySetResult("Downloaded string");
}
else
{
throw new Exception("Unexpected host! :-O");
}
return(tcs.Task);
});
// It should work...
(await webStore.GetString()).ShouldBe("Downloaded string");
// ...but two calls should be made
callCount.ShouldBe(2);
}
public async Task HttpFailedCallDoesNotQuaranteenUrl()
{
var callCount = 0;
var webStore = new TestWebStore(2, new BaseUris(new[] { "http://localhost" }, MultiUriSelectionStrategyFactory.Default), "test user agent");
webStore.WebClientMock
.Setup(x => x.DownloadStringAsync(It.IsAny <Uri>(), It.IsAny <CancellationToken>()))
.Returns(() =>
{
TaskCompletionSource <string> tcs = new TaskCompletionSource <string>();
if (callCount++ == 0)
{
// the first call fails with a protocol error (i e an HTTP error response)
tcs.TrySetException(new WebException("Resource not found", WebExceptionStatus.ProtocolError));
}
else
{
tcs.TrySetResult("Downloaded string");
}
return(tcs.Task);
});
// first call fails on name resolution, so URL should be quaranteened for some time
await webStore.GetString().ShouldThrowAsync <AggregateException>();
// second call should not fail...
(await webStore.GetString()).ShouldBe("Downloaded string");
// ...and two calls should be made
callCount.ShouldBe(2);
}
public async Task FailedCallQuaranteensUrl_OneUri()
{
var callCount = 0;
var webStore = new TestWebStore(2, new BaseUris(new[] { "http://localhost" }, MultiUriSelectionStrategyFactory.Default), "test user agent");
webStore.WebClientMock
.Setup(x => x.DownloadStringAsync(It.IsAny <Uri>(), It.IsAny <CancellationToken>()))
.Returns(() =>
{
TaskCompletionSource <string> tcs = new TaskCompletionSource <string>();
if (callCount++ == 0)
{
// the first call fails with a name resolution failure
tcs.TrySetException(new WebException("Server not found", WebExceptionStatus.NameResolutionFailure));
}
else
{
tcs.TrySetResult("Downloaded string");
}
return(tcs.Task);
});
// first call fails on name resolution, so URL should be quaranteened for some time
await webStore.GetString().ShouldThrowAsync <AggregateException>();
// second call should not fail...
(await webStore.GetString()).ShouldBe("Downloaded string");
// since the second call should fail on the URL being quaranteened, the second call should not even be attempted
callCount.ShouldBe(2);
}
public async Task FailedCallQuaranteensUrl_TwoUris_FirstRoundFails_SecondRoundWorks()
{
var callCount = 0;
var webStore = new TestWebStore(2, new BaseUris(new[] { "http://localhost", "http://localhost2" }, MultiUriSelectionStrategyFactory.Default), "test user agent");
bool serverFound = true;
webStore.WebClientMock
.Setup(x => x.DownloadStringAsync(It.IsAny <Uri>(), It.IsAny <CancellationToken>()))
.Returns <Uri, CancellationToken>((uri, ct) =>
{
callCount++;
TaskCompletionSource <string> tcs = new TaskCompletionSource <string>();
if (serverFound)
{
tcs.TrySetResult("Downloaded string");
}
else
{
tcs.TrySetException(new WebException("Server not found", WebExceptionStatus.NameResolutionFailure));
}
return(tcs.Task);
});
serverFound = false;
await webStore.GetString().ShouldThrowAsync <AggregateException>();
callCount.ShouldBe(2);
callCount = 0;
serverFound = true;
(await webStore.GetString()).ShouldBe("Downloaded string");
callCount.ShouldBe(1);
}
