/// <summary>
/// Test the source by exhaustively consuming it, requiring it to support the
/// <see cref="IAsyncFusedEnumerator{T}"/> interface, and returning
/// a TestObserver with the results.
/// </summary>
/// <typeparam name="T">The element type of the sequence.</typeparam>
/// <param name="source">The async enumerable sequence to test.</param>
/// <returns>The task with the TestObserver instance</returns>
public static async Task <TestObserver <T> > TestAsyncFused <T>(this IAsyncEnumerable <T> source)
{
var to = new TestObserver <T>();
var en = source.GetAsyncEnumerator();
var f = en as IAsyncFusedEnumerator <T>;
if (f == null)
{
throw new ArgumentException("The IAsyncEnumerator returned by source is not fuseable");
}
try
{
for (; ;)
{
var v = f.TryPoll(out var state);
if (state == AsyncFusedState.Ready)
{
to.OnNext(v);
}
else if (state == AsyncFusedState.Terminated)
{
to.OnCompleted();
break;
}
else if (!await en.MoveNextAsync())
{
to.OnCompleted();
break;
}
}
}
catch (Exception ex)
{
to.OnError(ex);
}
finally
{
await en.DisposeAsync();
}
return(to);
}
/// <summary>
/// Test the source by exhaustively consuming it and returning
/// a TestObserver with the results.
/// </summary>
/// <typeparam name="T">The element type of the sequence.</typeparam>
/// <param name="source">The async enumerable sequence to test.</param>
/// <returns>The task with the TestObserver instance</returns>
public static async Task <TestObserver <T> > TestAsync <T>(this IAsyncEnumerable <T> source)
{
var to = new TestObserver <T>();
var en = source.GetAsyncEnumerator();
try
{
while (await en.MoveNextAsync())
{
to.OnNext(en.Current);
}
to.OnCompleted();
}
catch (Exception ex)
{
to.OnError(ex);
}
finally
{
await en.DisposeAsync();
}
return(to);
}