public async Task OnNextAsync_TracerIsNull_DoesNotThrowException()
{
// Arrange
var sut = new TracingObserver <MockMessage>(_observerMock.Object);
// Act
await sut.OnNextAsync(new MockMessage());
// Assert
_observerMock.Verify(x => x.OnNextAsync(It.IsAny <MockMessage>(), It.IsAny <StreamSequenceToken>()), Times.Once);
VerifyNotOtherCalls();
}
public async Task OnNextAsync_WithTracing_Success()
{
// Arrange
var spanMock = new Mock <TelemetrySpan>();
_tracerMock.Setup(x => x.StartSpanFromActivity(It.IsAny <string>(), It.IsAny <Activity>(), SpanKind.Consumer, null))
.Returns(spanMock.Object);
var sut = new TracingObserver <MockMessage>(_observerMock.Object, _tracerMock.Object);
// Act
await sut.OnNextAsync(new MockMessage());
// Assert
_tracerMock.Verify(x => x.StartSpanFromActivity(It.IsAny <string>(), It.IsAny <Activity>(), SpanKind.Consumer, null), Times.Once);
_observerMock.Verify(x => x.OnNextAsync(It.IsAny <MockMessage>(), It.IsAny <StreamSequenceToken>()), Times.Once);
spanMock.Verify(x => x.End(), Times.Once);
VerifyNotOtherCalls();
}
/// <summary>
/// Subscribes a consumer to this observable, adding tracing in the consumption of items.
/// </summary>
/// <param name="observer">The <see cref="IAsyncObserver{T}"/> to subscribe.</param>
/// <param name="token">The <see cref="StreamSequenceToken"/> to be used as an offset to start the subscription from.</param>
/// <returns>A promise for a StreamSubscriptionHandle that represents the subscription. The
/// consumer may unsubscribe by using this handle. The subscription remains active
/// for as long as it is not explicitly unsubscribed.
///</returns>
public async Task <StreamSubscriptionHandle <TMessage> > SubscribeAsync(IAsyncObserver <TMessage> observer, StreamSequenceToken token = null)
{
var tracingObserver = new TracingObserver <TMessage>(observer, _tracer);
return(await _asyncStream.SubscribeAsync(tracingObserver, token));
}