Added the Model Comparison assistant for blind comparisons of two models (#1009)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/Tests/Assistants/ModelComparison/ModelComparisonRequestTests.cs

@@ -0,0 +1,163 @@
+using AIStudio.Assistants.ModelComparison;
+
+namespace AIStudio.Tests.Assistants.ModelComparison;
+
+/// <summary>
+/// Checks the text both models receive.
+/// </summary>
+/// <remarks>
+/// A difference in this text would be measured as a difference between the models, so what matters
+/// is that the shape stays the same, and that a request without a context is not dressed up.
+/// </remarks>
+[TestFixture]
+public sealed class ModelComparisonRequestTests
+{
+    [Test]
+    public void AQuestionAloneIsSentAsItIs()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "What is the capital of France?");
+
+        Assert.That(request.ToPrompt(), Is.EqualTo("What is the capital of France?"));
+    }
+
+    [Test]
+    public void TheMaterialAndAQuestionAreSeparatedByHeadings()
+    {
+        var request = new ModelComparisonRequest("The document.", "Summarize it.");
+
+        Assert.That(request.ToPrompt(), Is.EqualTo("# Material\nThe document.\n\n# Question or task\nSummarize it."));
+    }
+
+    /// <summary>
+    /// Checks that the request can stand below a heading of another prompt as one part of it.
+    /// </summary>
+    [Test]
+    public void TheHeadingsCanStandOneLevelDeeper()
+    {
+        var request = new ModelComparisonRequest("The document.", "Summarize it.");
+
+        Assert.That(request.ToPrompt(headingLevel: 2), Is.EqualTo("## Material\nThe document.\n\n## Question or task\nSummarize it."));
+    }
+
+    [Test]
+    public void AHeadingLevelBelowOneIsRefused()
+    {
+        var request = new ModelComparisonRequest("The document.", "Summarize it.");
+
+        Assert.Throws<ArgumentOutOfRangeException>(() => request.ToPrompt(headingLevel: 0));
+    }
+
+    [TestCase("")]
+    [TestCase("   ")]
+    [TestCase("\r\n\t\n")]
+    public void AContextOfWhiteSpaceCountsAsNone(string context)
+    {
+        var request = new ModelComparisonRequest(context, "Summarize it.");
+
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(request.Context, Is.Empty);
+            Assert.That(request.ToPrompt(), Is.EqualTo("Summarize it."));
+        }
+    }
+
+    [Test]
+    public void WhiteSpaceAroundTheTextsIsDropped()
+    {
+        var request = new ModelComparisonRequest("\n\nThe document.\n", "  Summarize it.  ");
+
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(request.Context, Is.EqualTo("The document."));
+            Assert.That(request.Question, Is.EqualTo("Summarize it."));
+        }
+    }
+
+    [Test]
+    public void AShortQuestionIsItsOwnPreview()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.");
+
+        Assert.That(request.GetQuestionPreview(), Is.EqualTo("Summarize it."));
+    }
+
+    [Test]
+    public void ALongQuestionIsCutAndMarked()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize this document in a few short sentences.");
+
+        Assert.That(request.GetQuestionPreview(18), Is.EqualTo("Summarize this doc…"));
+    }
+
+    [Test]
+    public void ACutDoesNotLeaveHalfOfACharacter()
+    {
+        // The emoji is two chars long. A cut after the first of them would leave a lone surrogate:
+        var request = new ModelComparisonRequest(string.Empty, "aaaa😀bbb");
+
+        Assert.That(request.GetQuestionPreview(5), Is.EqualTo("aaaa…"));
+    }
+
+    [Test]
+    public void ThePreviewOfAnEmptyLengthIsRefused()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.");
+
+        Assert.Throws<ArgumentOutOfRangeException>(() => request.GetQuestionPreview(0));
+    }
+
+    [Test]
+    public void TheSameInputAlwaysBuildsTheSamePrompt()
+    {
+        var first = new ModelComparisonRequest("The document.", "Summarize it.");
+        var second = new ModelComparisonRequest("The document.", "Summarize it.");
+
+        Assert.That(first.ToPrompt(), Is.EqualTo(second.ToPrompt()));
+    }
+
+    [Test]
+    public void WithoutALanguageNameThePromptNamesNone()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.");
+
+        Assert.That(request.ToPrompt(), Does.Not.Contain("Answer in"));
+    }
+
+    [Test]
+    public void ALanguageNameIsAppendedAsAnInstruction()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.", "German");
+
+        Assert.That(request.ToPrompt(), Is.EqualTo("Summarize it.\n\nAnswer in German."));
+    }
+
+    [Test]
+    public void WithoutACacheBusterThePromptIsUnchanged()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.");
+
+        Assert.That(request.ToPrompt(), Is.EqualTo(request.ToPrompt(string.Empty)));
+    }
+
+    [Test]
+    public void ACacheBusterIsAppendedAsAPlainlyLabeledLine()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.");
+
+        var prompt = request.ToPrompt("a1b2c3");
+
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(prompt, Does.StartWith("Summarize it."));
+            Assert.That(prompt, Does.Contain("a1b2c3"));
+        }
+    }
+
+    [Test]
+    public void TwoDifferentCacheBustersBuildDifferentPrompts()
+    {
+        var request = new ModelComparisonRequest(string.Empty, "Summarize it.");
+
+        Assert.That(request.ToPrompt("one"), Is.Not.EqualTo(request.ToPrompt("two")));
+    }
+}