public async Task CancelledWhileProcessingTest()
{
var source = new[] { true, false };
var cts = new CancellationTokenSource();
await AsyncParallel.ForEach(
source, new ParallelOptions { CancellationToken = cts.Token, MaxDegreeOfParallelism = 1 },
async b =>
{
if (b)
cts.Cancel();
else
Assert.Fail();
});
}