aspnetcore/src/Components/test/E2ETest/ServerExecutionTests/PrerenderingTest.cs

// 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.Net;
using System.Net.Http;
using System.Threading.Tasks;
using BasicTestApp;
using Microsoft.AspNetCore.Components.E2ETest.Infrastructure;
using Microsoft.AspNetCore.Components.E2ETest.Infrastructure.ServerFixtures;
using Microsoft.AspNetCore.E2ETesting;
using OpenQA.Selenium;
using TestServer;
using Xunit;
using Xunit.Abstractions;

namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
{
    [Collection("auth")] // Because auth uses cookies, this can't run in parallel with other auth tests
    public class PrerenderingTest : ServerTestBase<BasicTestAppServerSiteFixture<PrerenderedStartup>>
    {
        public PrerenderingTest(
            BrowserFixture browserFixture,
            BasicTestAppServerSiteFixture<PrerenderedStartup> serverFixture,
            ITestOutputHelper output)
            : base(browserFixture, serverFixture, output)
        {
        }

        [Fact]
        public void CanTransitionFromPrerenderedToInteractiveMode()
        {
            Navigate("/prerendered/prerendered-transition");

            // Prerendered output shows "not connected"
            Browser.Equal("not connected", () => Browser.FindElement(By.Id("connected-state")).Text);

            // Once connected, output changes
            BeginInteractivity();
            Browser.Equal("connected", () => Browser.FindElement(By.Id("connected-state")).Text);

            // ... and now the counter works
            Browser.FindElement(By.Id("increment-count")).Click();
            Browser.Equal("1", () => Browser.FindElement(By.Id("count")).Text);
        }

        [Fact]
        public void CanUseJSInteropFromOnAfterRenderAsync()
        {
            Navigate("/prerendered/prerendered-interop");

            // Prerendered output can't use JSInterop
            Browser.Equal("No value yet", () => Browser.FindElement(By.Id("val-get-by-interop")).Text);
            Browser.Equal(string.Empty, () => Browser.FindElement(By.Id("val-set-by-interop")).GetAttribute("value"));

            BeginInteractivity();

            // Once connected, we can
            Browser.Equal("Hello from interop call", () => Browser.FindElement(By.Id("val-get-by-interop")).Text);
            Browser.Equal("Hello from interop call", () => Browser.FindElement(By.Id("val-set-by-interop")).GetAttribute("value"));
        }

        [Fact]
        public void CanReadUrlHashOnlyOnceConnected()
        {
            var urlWithoutHash = "prerendered/show-uri?my=query&another=value";
            var url = $"{urlWithoutHash}#some/hash?tokens";

            // The server doesn't receive the hash part of the URL, so you can't
            // read it during prerendering
            Navigate(url);
            Browser.Equal(
                _serverFixture.RootUri + urlWithoutHash,
                () => Browser.FindElement(By.TagName("strong")).Text);

            // Once connected, you do have access to the full URL
            BeginInteractivity();
            Browser.Equal(
                _serverFixture.RootUri + url,
                () => Browser.FindElement(By.TagName("strong")).Text);
        }

        [Theory]
        [InlineData("base/relative", "prerendered/base/relative")]
        [InlineData("/root/relative", "/root/relative")]
        [InlineData("http://absolute/url", "http://absolute/url")]
        public async Task CanRedirectDuringPrerendering(string destinationParam, string expectedRedirectionLocation)
        {
            var requestUri = new Uri(
                _serverFixture.RootUri,
                "prerendered/prerendered-redirection?destination=" + destinationParam);

            var httpClient = new HttpClient(new HttpClientHandler { AllowAutoRedirect = false });
            var response = await httpClient.GetAsync(requestUri);

            var expectedUri = new Uri(_serverFixture.RootUri, expectedRedirectionLocation);
            Assert.Equal(HttpStatusCode.Redirect, response.StatusCode);
            Assert.Equal(expectedUri, response.Headers.Location);
        }

        [Theory]
        [InlineData(null, null)]
        [InlineData(null, "Bert")]
        [InlineData("Bert", null)]
        [InlineData("Bert", "Treb")]
        public void CanAccessAuthenticationStateDuringStaticPrerendering(string initialUsername, string interactiveUsername)
        {
            // See that the authentication state is usable during the initial prerendering
            SignInAs(initialUsername, null);
            Navigate("/prerendered/prerendered-transition");
            Browser.Equal($"Hello, {initialUsername ?? "anonymous"}!", () => Browser.FindElement(By.TagName("h1")).Text);

            // See that during connection, we update to whatever the latest authentication state now is
            SignInAs(interactiveUsername, null, useSeparateTab: true);
            BeginInteractivity();
            Browser.Equal($"Hello, {interactiveUsername ?? "anonymous"}!", () => Browser.FindElement(By.TagName("h1")).Text);
        }

        private void BeginInteractivity()
        {
            Browser.FindElement(By.Id("load-boot-script")).Click();
        }

        private void SignInAs(string userName, string roles, bool useSeparateTab = false) =>
            Browser.SignInAs(new Uri(_serverFixture.RootUri, "/prerendered/"), userName, roles, useSeparateTab);
    }
}