Added the BeyondFacts Lab as a prototype (#1175)

app/Tests/BeyondFactsLab/BflPreviewFeatureTests.cs

@@ -0,0 +1,68 @@
+using AIStudio.Settings;
+using AIStudio.Settings.DataModel;
+
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace AIStudio.Tests.BeyondFactsLab;
+
+/// <summary>
+/// Checks that the BeyondFacts Lab stays a prototype which nobody sees unless they ask for it.
+/// </summary>
+/// <remarks>
+/// The lab grows over a long series of pull requests. Until it is complete, only people who allow
+/// prototypes and switch the lab on may find it; raising its level is a decision of its own.
+/// </remarks>
+[TestFixture]
+public sealed class BflPreviewFeatureTests
+{
+    [TestCase(PreviewVisibility.PROTOTYPE)]
+    [TestCase(PreviewVisibility.EXPERIMENTAL)]
+    public void PrototypesOfferTheLab(PreviewVisibility visibility)
+    {
+        Assert.That(visibility.GetPreviewFeatures(), Does.Contain(PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026));
+    }
+
+    [TestCase(PreviewVisibility.NONE)]
+    [TestCase(PreviewVisibility.RELEASE_CANDIDATE)]
+    [TestCase(PreviewVisibility.BETA)]
+    [TestCase(PreviewVisibility.ALPHA)]
+    public void LowerLevelsDoNotOfferTheLab(PreviewVisibility visibility)
+    {
+        Assert.That(visibility.GetPreviewFeatures(), Does.Not.Contain(PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026));
+    }
+
+    [Test]
+    public void LoweringTheLevelLeavesTheLabOut()
+    {
+        var enabled = new HashSet<PreviewFeatures> { PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026 };
+
+        Assert.That(PreviewVisibility.BETA.FilterPreviewFeatures(enabled), Is.Empty, "A beta level must not keep a prototype switched on.");
+    }
+
+    [Test]
+    public void TheLabIsNotReleased()
+    {
+        Assert.That(PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026.IsReleased, Is.False);
+    }
+
+    [Test]
+    public void TheLabCountsOnlyWhenSwitchedOn()
+    {
+        var settingsManager = new SettingsManager(NullLogger<SettingsManager>.Instance, null!);
+        var wasEnabledBefore = PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026.IsEnabled(settingsManager);
+
+        settingsManager.ConfigurationData.App.EnabledPreviewFeatures.Add(PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026);
+
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(wasEnabledBefore, Is.False, "New settings must not switch the lab on.");
+            Assert.That(PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026.IsEnabled(settingsManager), Is.True);
+        }
+    }
+
+    [Test]
+    public void TheLabHasADescription()
+    {
+        Assert.That(PreviewFeatures.PRE_BEYOND_FACTS_LAB_2026.PreviewDescription, Does.StartWith("BeyondFacts Lab"), "The settings list the preview features by this text.");
+    }
+}