public void SetException_OperationCanceledException_CancelsTask()
{
AsyncValueTaskMethodBuilder<int> b = ValueTask<int>.CreateAsyncMethodBuilder();
var e = new OperationCanceledException();
ValueTask<int> vt = b.Task;
b.SetException(e);
Assert.True(vt.IsCanceled);
Assert.Same(e, Assert.Throws<OperationCanceledException>(() => vt.GetAwaiter().GetResult()));
}
public static IEnumerable<object[]> CanceledTasksAndExpectedCancellationExceptions()
{
var cts = new CancellationTokenSource();
var oce = new OperationCanceledException(cts.Token);
// Scheduled Task
Task<int> generic = Task.Run<int>(new Func<int>(() =>
{
cts.Cancel();
throw oce;
}), cts.Token);
yield return new object[] { LineNumber(), generic, oce };
Task nonGeneric = generic;
// WhenAll Task and Task<int>
yield return new object[] { LineNumber(), Task.WhenAll(generic), oce };
yield return new object[] { LineNumber(), Task.WhenAll(generic, Task.FromResult(42)), oce };
yield return new object[] { LineNumber(), Task.WhenAll(Task.FromResult(42), generic), oce };
yield return new object[] { LineNumber(), Task.WhenAll(generic, generic, generic), oce };
yield return new object[] { LineNumber(), Task.WhenAll(nonGeneric), oce };
yield return new object[] { LineNumber(), Task.WhenAll(nonGeneric, Task.FromResult(42)), oce };
yield return new object[] { LineNumber(), Task.WhenAll(Task.FromResult(42), nonGeneric), oce };
yield return new object[] { LineNumber(), Task.WhenAll(nonGeneric, nonGeneric, nonGeneric), oce };
// Task.Run Task and Task<int> with unwrapping
yield return new object[] { LineNumber(), Task.Run(() => generic), oce };
yield return new object[] { LineNumber(), Task.Run(() => nonGeneric), oce };
// A FromAsync Task and Task<int>
yield return new object[] { LineNumber(), Task.Factory.FromAsync(generic, new Action<IAsyncResult>(ar => { throw oce; })), oce };
yield return new object[] { LineNumber(), Task<int>.Factory.FromAsync(nonGeneric, new Func<IAsyncResult, int>(ar => { throw oce; })), oce };
// AsyncTaskMethodBuilder
var atmb = new AsyncTaskMethodBuilder();
atmb.SetException(oce);
yield return new object[] { LineNumber(), atmb.Task, oce };
}
public static void OperationCanceledException_PropagatesThroughCanceledTask(int lineNumber, Task task, OperationCanceledException expected)
{
var caught = Assert.ThrowsAny<OperationCanceledException>(() => task.GetAwaiter().GetResult());
Assert.Same(expected, caught);
}
