public void AwaitOnCompleted_ForcesTaskCreation(int numAwaits, bool awaitUnsafe)
{
AsyncValueTaskMethodBuilder <int> b = ValueTask <int> .CreateAsyncMethodBuilder();
var dsm = new DelegateStateMachine();
TaskAwaiter <int> t = new TaskCompletionSource <int>().Task.GetAwaiter();
Assert.InRange(numAwaits, 1, int.MaxValue);
for (int i = 1; i <= numAwaits; i++)
{
if (awaitUnsafe)
{
b.AwaitUnsafeOnCompleted(ref t, ref dsm);
}
else
{
b.AwaitOnCompleted(ref t, ref dsm);
}
}
b.SetResult(42);
Assert.True(WrapsTask(b.Task));
Assert.Equal(42, b.Task.Result);
}
public void SetStateMachine_InvalidArgument_ThrowsException()
{
AsyncValueTaskMethodBuilder <int> b = ValueTask <int> .CreateAsyncMethodBuilder();
Assert.Throws <ArgumentNullException>("stateMachine", () => b.SetStateMachine(null));
b.SetStateMachine(new DelegateStateMachine());
}
public async Task AwaitOnCompleted_InvokesStateMachineMethods(bool awaitUnsafe)
{
AsyncValueTaskMethodBuilder <int> b = ValueTask <int> .CreateAsyncMethodBuilder();
var ignored = b.Task;
var callbackCompleted = new TaskCompletionSource <bool>();
IAsyncStateMachine foundSm = null;
var dsm = new DelegateStateMachine
{
MoveNextDelegate = () => callbackCompleted.SetResult(true),
SetStateMachineDelegate = sm => foundSm = sm
};
TaskAwaiter t = Task.CompletedTask.GetAwaiter();
if (awaitUnsafe)
{
b.AwaitUnsafeOnCompleted(ref t, ref dsm);
}
else
{
b.AwaitOnCompleted(ref t, ref dsm);
}
await callbackCompleted.Task;
Assert.Equal(dsm, foundSm);
}
public void Start_ExecutionContextChangesInMoveNextDontFlowOut()
{
var al = new AsyncLocal<int> { Value = 0 };
int calls = 0;
var dsm = new DelegateStateMachine
{
MoveNextDelegate = () =>
{
al.Value++;
calls++;
}
};
dsm.MoveNext();
Assert.Equal(1, al.Value);
Assert.Equal(1, calls);
dsm.MoveNext();
Assert.Equal(2, al.Value);
Assert.Equal(2, calls);
AsyncValueTaskMethodBuilder<int> b = ValueTask<int>.CreateAsyncMethodBuilder();
b.Start(ref dsm);
Assert.Equal(2, al.Value); // change should not be visible
Assert.Equal(3, calls);
// Make sure we've not caused the Task to be allocated
b.SetResult(42);
ValueTask<int> vt = b.Task;
Assert.NotSame(vt.AsTask(), vt.AsTask());
}
public void Start_InvokesMoveNext()
{
AsyncValueTaskMethodBuilder<int> b = ValueTask<int>.CreateAsyncMethodBuilder();
int invokes = 0;
var dsm = new DelegateStateMachine { MoveNextDelegate = () => invokes++ };
b.Start(ref dsm);
Assert.Equal(1, invokes);
}
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 void SetException_AfterAccessTask_FaultsTask()
{
AsyncValueTaskMethodBuilder<int> b = ValueTask<int>.CreateAsyncMethodBuilder();
var e = new FormatException();
ValueTask<int> vt = b.Task;
b.SetException(e);
Assert.True(vt.IsFaulted);
Assert.Same(e, Assert.Throws<FormatException>(() => vt.GetAwaiter().GetResult()));
}
public void SetResult_AfterAccessTask_ValueTaskContainsValue()
{
AsyncValueTaskMethodBuilder<int> b = ValueTask<int>.CreateAsyncMethodBuilder();
ValueTask<int> vt = b.Task;
b.SetResult(42);
Assert.True(vt.IsCompletedSuccessfully);
Assert.Same(vt.AsTask(), vt.AsTask()); // will be safe if completed asynchronously
Assert.Equal(42, vt.Result);
}
public void SetResult_AfterAccessTask_ValueTaskContainsValue()
{
AsyncValueTaskMethodBuilder <int> b = ValueTask <int> .CreateAsyncMethodBuilder();
ValueTask <int> vt = b.Task;
b.SetResult(42);
Assert.True(vt.IsCompletedSuccessfully);
Assert.True(WrapsTask(vt));
Assert.Equal(42, vt.Result);
}
public void Create_ReturnsDefaultInstance()
{
AsyncValueTaskMethodBuilder <int> b = ValueTask <int> .CreateAsyncMethodBuilder();
Assert.Equal(default(AsyncValueTaskMethodBuilder <int>), b); // implementation detail being verified
}
