private async Task <AuthorizationResult> AcquireAuthCodeAsync( string redirectUri = TestRedirectUri, string requestUri = TestAuthorizationRequestUri, string responseUriString = TestAuthorizationResponseUri) { // Arrange var requestContext = new RequestContext(TestCommon.CreateDefaultServiceBundle(), Guid.NewGuid()); var responseUri = new Uri(responseUriString); IWebUI webUI = new DefaultOsBrowserWebUi(_platformProxy, _logger, _tcpInterceptor); _tcpInterceptor.ListenToSingleRequestAndRespondAsync( TestPort, Arg.Any <Func <Uri, string> >(), CancellationToken.None) .Returns(Task.FromResult(responseUri)); // Act AuthorizationResult authorizationResult = await webUI.AcquireAuthorizationAsync( new Uri(requestUri), new Uri(redirectUri), requestContext, CancellationToken.None).ConfigureAwait(false); // Assert that we opened the browser await _platformProxy.Received(1).StartDefaultOsBrowserAsync(requestUri) .ConfigureAwait(false); return(authorizationResult); }