feature: Phase 23 Track A — env-gated /robots.txt + /sitemap.xml public crawl endpoints

DeepDrftTests/RobotsTxtTests.cs

@@ -0,0 +1,62 @@
+using DeepDrftPublic.Seo;
+
+namespace DeepDrftTests;
+
+/// <summary>
+/// Unit tests for <see cref="RobotsTxt"/> — the pure environment-branch composition of the robots.txt body
+/// (Phase 23 wave 23.1). The gate (Production vs. anything-else) is the load-bearing branch: Production
+/// allows + points at the sitemap and disallows the non-page routes; every non-production environment is a
+/// closed door with no sitemap pointer (Invariant E1).
+/// </summary>
+[TestFixture]
+public class RobotsTxtTests
+{
+    private const string BaseUrl = "https://deepdrft.com";
+
+    [Test]
+    public void Build_Production_AllowsAndPointsAtSitemap()
+    {
+        var body = RobotsTxt.Build(isProduction: true, BaseUrl);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(body, Does.Contain("User-agent: *"));
+            Assert.That(body, Does.Contain("Allow: /"));
+            Assert.That(body, Does.Contain("Sitemap: https://deepdrft.com/sitemap.xml"));
+        });
+    }
+
+    [Test]
+    public void Build_Production_DisallowsFramePlayerAndApi()
+    {
+        var body = RobotsTxt.Build(isProduction: true, BaseUrl);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(body, Does.Contain("Disallow: /FramePlayer"));
+            Assert.That(body, Does.Contain("Disallow: /api/"));
+        });
+    }
+
+    [Test]
+    public void Build_NonProduction_DisallowsEverythingWithNoSitemapPointer()
+    {
+        var body = RobotsTxt.Build(isProduction: false, BaseUrl);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(body, Does.Contain("User-agent: *"));
+            Assert.That(body, Does.Contain("Disallow: /"));
+            Assert.That(body, Does.Not.Contain("Allow:"));
+            Assert.That(body, Does.Not.Contain("Sitemap:"));
+        });
+    }
+
+    [Test]
+    public void Build_Production_TrimsTrailingSlashOnBaseUrl()
+    {
+        var body = RobotsTxt.Build(isProduction: true, "https://deepdrft.com/");
+
+        Assert.That(body, Does.Contain("Sitemap: https://deepdrft.com/sitemap.xml"));
+    }
+}