public async Task CouldUseIDeltaMethods()
{
var tasks = new ValueTask <int> [4];
tasks[0] = new ValueTask <int>(1);
tasks[1] = new ValueTask <int>(Task.Run(async() =>
{
await Task.Delay(100);
return(42);
}));
tasks[2] = new ValueTask <int>(Task.Run(async() =>
{
await Task.Delay(200);
ThrowHelper.ThrowInvalidOperationException();
return(0);
}));
tasks[3] = new ValueTask <int>(Task.Run <int>(async() => throw new OperationCanceledException()));
await tasks.WhenAll();
Assert.AreEqual(tasks[0].Result, 1);
Assert.AreEqual(tasks[1].Result, 42);
Assert.IsTrue(tasks[2].IsFaulted);
Assert.IsTrue(tasks[3].IsCanceled);
Assert.Throws <InvalidOperationException>(() =>
{
var _ = tasks[2].Result;
});
Assert.Throws <OperationCanceledException>(() =>
{
var _ = tasks[3].Result;
});
}