public async Task SendAsync_NoContextSet_RequestThrows_CleansUpContext()
{
// Arrange
var policy = Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(10));
var handler = new TestPolicyHttpMessageHandler(policy);
Context context = null;
handler.OnSendAsync = (req, c, ct) =>
{
context = c;
throw new OperationCanceledException();
};
var request = new HttpRequestMessage();
// Act
var exception = await Assert.ThrowsAsync <OperationCanceledException>(async() =>
{
await handler.SendAsync(request, CancellationToken.None);
});
// Assert
Assert.NotNull(context); // The handler did generate a context for the execution.
Assert.Null(request.GetPolicyExecutionContext()); // We do clean up a context we generated, when the execution throws.
}
public void SendAsync_WorksInSingleThreadedSyncContext()
{
// Arrange
var policy = Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(10));
var handler = new TestPolicyHttpMessageHandler(policy);
handler.OnSendAsync = async(req, c, ct) =>
{
await Task.Delay(1).ConfigureAwait(false);
return(null);
};
var hangs = true;
// Act
using (var cts = new CancellationTokenSource(TimeSpan.FromSeconds(3)))
{
var token = cts.Token;
token.Register(() => throw new OperationCanceledException(token));
SingleThreadedSynchronizationContext.Run(() =>
{
// Act
var request = new HttpRequestMessage();
handler.SendAsync(request, CancellationToken.None).GetAwaiter().GetResult();
hangs = false;
});
}
// Assert
Assert.False(hangs);
}
public async Task SendAsync_ExistingContext_ReusesContext()
{
// Arrange
var policy = Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(10));
var handler = new TestPolicyHttpMessageHandler(policy);
var expected = new HttpResponseMessage();
var expectedContext = new Context(Guid.NewGuid().ToString());
Context context = null;
handler.OnSendAsync = (req, c, ct) =>
{
context = c;
Assert.NotNull(c);
Assert.Same(c, req.GetPolicyExecutionContext());
return(Task.FromResult(expected));
};
var request = new HttpRequestMessage();
request.SetPolicyExecutionContext(expectedContext);
// Act
var response = await handler.SendAsync(request, CancellationToken.None);
// Assert
Assert.Same(expectedContext, context);
Assert.Same(expectedContext, request.GetPolicyExecutionContext()); // We don't clean up the context if the caller or earlier delegating handlers had supplied it.
Assert.Same(expected, response);
}
public async Task SendAsync_NoContextSet_CreatesNewContext()
{
// Arrange
var policy = Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(10));
var handler = new TestPolicyHttpMessageHandler(policy);
Context context = null;
var expected = new HttpResponseMessage();
handler.OnSendAsync = (req, c, ct) =>
{
context = c;
Assert.NotNull(context);
Assert.Same(context, req.GetPolicyExecutionContext());
return(Task.FromResult(expected));
};
var request = new HttpRequestMessage();
// Act
var response = await handler.SendAsync(request, CancellationToken.None);
// Assert
Assert.NotNull(context);
Assert.Null(request.GetPolicyExecutionContext()); // We clean up the context if it was generated by the handler rather than caller supplied.
Assert.Same(expected, response);
}
public async Task SendAsync_DynamicPolicy_PolicyTriggers_CanReexecuteSendAsync()
{
// Arrange
var policy = Policy <HttpResponseMessage>
.Handle <HttpRequestException>()
.RetryAsync(retryCount: 5);
var expectedRequest = new HttpRequestMessage();
HttpRequestMessage policySelectorRequest = null;
var handler = new TestPolicyHttpMessageHandler((req) =>
{
policySelectorRequest = req;
return(policy);
});
var callCount = 0;
var expected = new HttpResponseMessage();
handler.OnSendAsync = (req, c, ct) =>
{
if (callCount == 0)
{
callCount++;
throw new HttpRequestException();
}
else if (callCount == 1)
{
callCount++;
return(Task.FromResult(expected));
}
else
{
throw new InvalidOperationException();
}
};
// Act
var response = await handler.SendAsync(expectedRequest, CancellationToken.None);
// Assert
Assert.Equal(2, callCount);
Assert.Same(expected, response);
Assert.Same(expectedRequest, policySelectorRequest);
}
public async Task SendAsync_PolicyCancellation_CanTriggerRequestCancellation()
{
// Arrange
var policy = Policy <HttpResponseMessage>
.Handle <TimeoutRejectedException>() // Handle timeouts by retrying
.RetryAsync(retryCount: 5)
.WrapAsync(Policy
.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromMilliseconds(50)) // Apply a 50ms timeout
.WrapAsync(Policy.NoOpAsync <HttpResponseMessage>()));
var handler = new TestPolicyHttpMessageHandler(policy);
var @event = new ManualResetEventSlim(initialState: false);
var callCount = 0;
var expected = new HttpResponseMessage();
handler.OnSendAsync = (req, c, ct) =>
{
// The inner cancellation token is created by Polly, it will trigger the timeout.
Assert.True(ct.CanBeCanceled);
if (callCount == 0)
{
callCount++;
@event.Wait(ct);
throw null; // unreachable, previous line should throw
}
else if (callCount == 1)
{
callCount++;
return(Task.FromResult(expected));
}
else
{
throw new InvalidOperationException();
}
};
// Act
var response = await handler.SendAsync(new HttpRequestMessage(), CancellationToken.None);
// Assert
Assert.Equal(2, callCount);
Assert.Same(expected, response);
}
public async Task SendAsync_NoContextSet_DynamicPolicySelectorThrows_CleansUpContext()
{
// Arrange
var handler = new TestPolicyHttpMessageHandler((req) =>
{
throw new InvalidOperationException();
});
var request = new HttpRequestMessage();
// Act
var exception = await Assert.ThrowsAsync <InvalidOperationException>(async() =>
{
await handler.SendAsync(request, CancellationToken.None);
});
// Assert
Assert.Null(request.GetPolicyExecutionContext()); // We do clean up a context we generated, when the policy selector throws.
}
public async Task SendAsync_DynamicPolicy_PolicySelectorReturnsNull_ThrowsException()
{
// Arrange
var handler = new TestPolicyHttpMessageHandler((req) =>
{
return(null);
});
var expected = new HttpResponseMessage();
// Act
var exception = await Assert.ThrowsAsync <InvalidOperationException>(async() =>
{
await handler.SendAsync(new HttpRequestMessage(), CancellationToken.None);
});
// Assert
Assert.Equal(
"The 'policySelector' function must return a non-null policy instance. To create a policy that takes no action, use 'Policy.NoOpAsync<HttpResponseMessage>()'.",
exception.Message);
}
