public async Task DefaultOsBrowserWebUi_CustomBrowser_Async() { bool customOpenBrowserCalled = false; var options = new SystemWebViewOptions() { OpenBrowserAsync = (Uri u) => { customOpenBrowserCalled = true; return(Task.FromResult(0)); } }; var webUI = CreateTestWebUI(options); var requestContext = new RequestContext(TestCommon.CreateDefaultServiceBundle(), Guid.NewGuid()); var responseUri = new Uri(TestAuthorizationResponseUri); _tcpInterceptor.ListenToSingleRequestAndRespondAsync( TestPort, "/", Arg.Any <Func <Uri, MessageAndHttpCode> >(), CancellationToken.None) .Returns(Task.FromResult(responseUri)); // Act AuthorizationResult authorizationResult = await webUI.AcquireAuthorizationAsync( new Uri(TestAuthorizationRequestUri), new Uri(TestRedirectUri), requestContext, CancellationToken.None).ConfigureAwait(false); // Assert that we didn't open the browser using platform proxy await _platformProxy.DidNotReceiveWithAnyArgs().StartDefaultOsBrowserAsync(default, requestContext.ServiceBundle.Config.IsBrokerEnabled)