End-to-end tests against the pasture; profiles, follows, search, votes, reactions

tests/e2e (Playwright for .NET 1.61.0 on xunit v3, the Chromium 1228 already
cached, never downloaded, never in CI) runs the published app against
SocialPub's pasture and its town: run.sh publishes it with the Pasture
environment (wwwroot/appsettings.Pasture.json, published only then; the
deploy fails if it ever ships) and serves it as https://decepub.test. The
tests sign in through the real login page and persona chooser, check that
every request goes only to decepub.test and privapub.test with the right
credential on the right API, render one post of each kind from each
platform as its author wrote it, and check every action on the other
side of the wire (town.sh stored): favourites, boosts and replies with
their undoing, follows from a profile, votes, reactions. Each test is also
a cell of the town's report (out/client.jsonl). They found two PrivaPub
bugs fixed there (a blocked author's status answered null; sensitive
remote media invented a content warning) and a reply addressed to nobody.

New in the app, all checked by those tests:
- profiles at /account/{id}: header, bio, fields, counts, the account's
  posts as posts, posts and replies, or media, and follow, unfollow,
  cancel a request, mute and block (AccountService); post authors and
  notifications open them in the app;
- search at /search: accounts, posts and hashtags, a handle or an address
  resolved by PrivaPub;
- poll voting on the card, and emoji reactions shown and given with one
  tap; before a persona's first reaction or vote it is told once that
  both are public (PublicNoticeService, the owner's decision);
- follow requests answered from their notification.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

tests/e2e/Support/Browser.cs

@@ -0,0 +1,101 @@
+using Microsoft.Playwright;
+
+[assembly: AssemblyFixture(typeof(decePubClient.E2E.Support.Browser))]
+
+namespace decePubClient.E2E.Support
+{
+	// One Chromium for the whole run. *.test names go to Caddy on 127.0.0.1:6443 (Chromium's own --resolve), whose
+	// certificates come from the pasture's private CA, so certificate errors are ignored; nothing else is reachable.
+	public sealed class Browser : IAsyncLifetime
+	{
+		IPlaywright _playwright;
+		public IBrowser Chromium { get; private set; }
+
+		public async ValueTask InitializeAsync()
+		{
+			_playwright = await Playwright.CreateAsync();
+			Chromium = await _playwright.Chromium.LaunchAsync(new()
+			{
+				Headless = Environment.GetEnvironmentVariable("E2E_HEADED") != "1",
+				Args = ["--host-resolver-rules=MAP *.test 127.0.0.1:6443"]
+			});
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (Chromium is not null)
+				await Chromium.CloseAsync();
+			_playwright?.Dispose();
+		}
+
+		public async Task<Session> Open(string storageState = null)
+		{
+			var context = await Chromium.NewContextAsync(new()
+			{
+				IgnoreHTTPSErrors = true,
+				Locale = "en-GB",
+				TimezoneId = "Europe/Rome",
+				ViewportSize = new() { Width = 1440, Height = 900 },
+				ServiceWorkers = ServiceWorkerPolicy.Block,
+				StorageStatePath = storageState
+			});
+			return new Session(context, await context.NewPageAsync());
+		}
+	}
+
+	// A browser tab and what it did: every request's host, every console error, every 5xx and Blazor's error bar. The
+	// guards hold for every test: the app talks only to its own site and to PrivaPub, and never fails silently.
+	public sealed class Session : IAsyncDisposable
+	{
+		public IBrowserContext Context { get; }
+		public IPage Page { get; }
+		public List<string> Hosts { get; } = [];
+		public List<string> ConsoleErrors { get; } = [];
+		public List<string> ServerErrors { get; } = [];
+		public List<(string Url, string Authorization)> ApiCalls { get; } = [];
+
+		public Session(IBrowserContext context, IPage page)
+		{
+			Context = context;
+			Page = page;
+			page.Request += (_, request) =>
+			{
+				var uri = new Uri(request.Url);
+				if (uri.Scheme is "http" or "https")
+					lock (Hosts)
+						Hosts.Add(uri.Host);
+				if (uri.Host == "privapub.test")
+					lock (ApiCalls)
+						ApiCalls.Add((request.Url, request.Headers.TryGetValue("authorization", out var auth) ? auth : null));
+			};
+			page.Console += (_, message) =>
+			{
+				if (message.Type == "error")
+					lock (ConsoleErrors)
+						ConsoleErrors.Add(message.Text);
+			};
+			page.Response += (_, response) =>
+			{
+				if (response.Status >= 500)
+					lock (ServerErrors)
+						ServerErrors.Add($"{response.Status} {response.Url}");
+			};
+		}
+
+		public async Task AssertGuards()
+		{
+			Assert.All(Hosts.Distinct(), host => Assert.Contains(host, new[] { "decepub.test", "privapub.test" }));
+			Assert.Empty(ServerErrors);
+			Assert.False(await Page.Locator("#blazor-error-ui").IsVisibleAsync(), "Blazor's error bar is showing");
+			// /clientapi carries the root's JWT and /api a persona's token: no credential ever crosses over
+			var clientApi = ApiCalls.Where(c => c.Authorization is not null && new Uri(c.Url).AbsolutePath.StartsWith("/clientapi/"))
+				.Select(c => c.Authorization).ToHashSet();
+			var mastodonApi = ApiCalls.Where(c => c.Authorization is not null && new Uri(c.Url).AbsolutePath.StartsWith("/api/"))
+				.Select(c => c.Authorization).ToHashSet();
+			Assert.Empty(clientApi.Intersect(mastodonApi));
+			Assert.All(clientApi, auth => Assert.Equal(3, auth["Bearer ".Length..].Split('.').Length));
+		}
+
+		public async ValueTask DisposeAsync() => await Context.CloseAsync();
+	}
+}