E2E tests for startup error notification

SteveSandersonMS · SteveSandersonMS · commit 17e979061b42 · 2019-12-10T13:46:25.000Z
diff --git a/src/Components/test/E2ETest/Tests/StartupErrorNotificationTest.cs b/src/Components/test/E2ETest/Tests/StartupErrorNotificationTest.cs
@@ -0,0 +1,39 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using BasicTestApp;
+using Microsoft.AspNetCore.E2ETesting;
+using Microsoft.AspNetCore.Components.E2ETest.Infrastructure;
+using Microsoft.AspNetCore.Components.E2ETest.Infrastructure.ServerFixtures;
+using OpenQA.Selenium;
+using Xunit.Abstractions;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Components.E2ETest.Tests
+{
+    public class StartupErrorNotificationTest : ServerTestBase<DevHostServerFixture<Program>>
+    {
+        public StartupErrorNotificationTest(
+            BrowserFixture browserFixture,
+            DevHostServerFixture<Program> serverFixture,
+            ITestOutputHelper output)
+            : base(browserFixture, serverFixture, output)
+        {
+        }
+
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public void DisplaysNotificationForStartupException(bool errorIsAsync)
+        {
+            var url = $"{ServerPathBase}?error={(errorIsAsync ? "async" : "sync")}";
+
+            Navigate(url, noReload: true);
+            var errorUiElem = Browser.Exists(By.Id("blazor-error-ui"), TimeSpan.FromSeconds(10));
+            Assert.NotNull(errorUiElem);
+
+            Browser.Equal("block", () => errorUiElem.GetCssValue("display"));
+        }
+    }
+}
diff --git a/src/Components/test/testassets/BasicTestApp/Program.cs b/src/Components/test/testassets/BasicTestApp/Program.cs
@@ -1,19 +1,19 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Globalization;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Blazor.Hosting;
+using Mono.WebAssembly.Interop;
 
 namespace BasicTestApp
 {
     public class Program
     {
         public static async Task Main(string[] args)
         {
-            // Later on, the startup APIs will be inherently asynchronous
-            // Until then, use this artificial means to show async main is working
-            await Task.Yield();
+            await SimulateErrorsIfNeededForTest();
 
             // We want the culture to be en-US so that the tests for bind can work consistently.
             CultureInfo.CurrentCulture = new CultureInfo("en-US");
@@ -24,5 +24,22 @@ public static async Task Main(string[] args)
         public static IWebAssemblyHostBuilder CreateHostBuilder(string[] args) =>
             BlazorWebAssemblyHost.CreateDefaultBuilder()
                 .UseBlazorStartup<Startup>();
+
+        // Supports E2E tests in StartupErrorNotificationTest
+        private static async Task SimulateErrorsIfNeededForTest()
+        {
+            var currentUrl = new MonoWebAssemblyJSRuntime().Invoke<string>("getCurrentUrl");
+            if (currentUrl.Contains("error=sync"))
+            {
+                throw new InvalidTimeZoneException("This is a synchronous startup exception");
+            }
+
+            await Task.Yield();
+
+            if (currentUrl.Contains("error=async"))
+            {
+                throw new InvalidTimeZoneException("This is an asynchronous startup exception");
+            }
+        }
     }
 }
diff --git a/src/Components/test/testassets/BasicTestApp/wwwroot/index.html b/src/Components/test/testassets/BasicTestApp/wwwroot/index.html
@@ -14,6 +14,12 @@
 <body>
     <root>Loading...</root>
 
+    <div id="blazor-error-ui">
+        An unhandled error has occurred.
+        <a href class='reload'>Reload</a>
+        <a class='dismiss' style="cursor: pointer;">🗙</a>
+    </div>
+
     <!-- Used for testing interop scenarios between JS and .NET -->
     <script src="js/jsinteroptests.js"></script>
 
@@ -27,6 +33,10 @@
         function navigationManagerNavigate() {
             Blazor.navigateTo('/subdir/some-path');
         }
+
+        function getCurrentUrl() {
+            return location.href;
+        }
     </script>
     <script src="_framework/blazor.webassembly.js"></script>
 
diff --git a/src/Components/test/testassets/BasicTestApp/wwwroot/style.css b/src/Components/test/testassets/BasicTestApp/wwwroot/style.css
@@ -7,11 +7,22 @@
 }
 
 #blazor-error-ui {
+    background: lightyellow;
+    bottom: 0;
+    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
     display: none;
+    left: 0;
+    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
+    position: fixed;
+    width: 100%;
+    z-index: 1000;
 }
 
-    #blazor-error-ui dismiss {
+    #blazor-error-ui .dismiss {
         cursor: pointer;
+        position: absolute;
+        right: 0.75rem;
+        top: 0.5rem;
     }
 
 .validation-message {
