public async Task OnError() { /* When */ var result = await ExecuteSubscribeAsync(new ExecutionOptions { Query = "subscription MessageAdded { messageAdded { from { id displayName } content sentAt } }", }).ConfigureAwait(false); Chat.AddError(new Exception("test")); /* Then */ var stream = result.Streams.Values.FirstOrDefault(); var error = await Should.ThrowAsync <ExecutionError>(async() => await stream.FirstOrDefaultAsync()).ConfigureAwait(false); error.InnerException.Message.ShouldBe("test"); error.Path.ShouldBe(new[] { "messageAdded" }); }