Rebuilt how AI Studio knows what a model can do (#960)

app/Tests/Models/ModelProfileTests.cs

@@ -0,0 +1,113 @@
+using AIStudio.Models;
+using AIStudio.Provider;
+
+namespace AIStudio.Tests.Models;
+
+/// <summary>
+/// Checks the answer object itself: what it says, and what it refuses to say.
+/// </summary>
+[TestFixture]
+public sealed class ModelProfileTests
+{
+    [Test]
+    public void AProfileNobodyWroteAnythingIntoKnowsNothingAndStillCountsAsAChatModel()
+    {
+        var untouched = ModelProfile.UNKNOWN;
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(untouched.Capabilities, Is.EqualTo(Capability.NONE));
+            Assert.That(untouched.Reasoning, Is.EqualTo(ReasoningSupport.NONE));
+            Assert.That(untouched.Context.IsKnown, Is.False);
+
+            //
+            // A model we fail to recognize has to stay visible to the user rather than disappear
+            // from their list, which is why the unrecognized kind is chat rather than something
+            // meaning "no idea".
+            //
+            Assert.That(untouched.Kind, Is.EqualTo(ModelKind.CHAT));
+        });
+    }
+
+    [Test]
+    public void AskingWhetherAModelHasSeveralCapabilitiesAsksForAllOfThem()
+    {
+        var profile = new ModelProfile { Capabilities = Capability.TEXT_INPUT | Capability.TEXT_OUTPUT };
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(profile.Has(Capability.TEXT_INPUT | Capability.TEXT_OUTPUT), Is.True);
+            Assert.That(profile.Has(Capability.TEXT_INPUT | Capability.WEB_SEARCH), Is.False);
+            Assert.That(profile.HasAny(Capability.TEXT_INPUT | Capability.WEB_SEARCH), Is.True);
+            Assert.That(profile.HasAny(Capability.WEB_SEARCH | Capability.EMBEDDING), Is.False);
+        });
+    }
+
+    [Test]
+    public void AskingForNoCapabilityAtAllIsAnsweredWithNo()
+    {
+        //
+        // Without this, a variable which happens to hold NONE would report every model as able to
+        // do it, because every set contains the empty set.
+        //
+        var profile = new ModelProfile { Capabilities = Capability.TEXT_INPUT };
+
+        Assert.That(profile.Has(Capability.NONE), Is.False);
+    }
+
+    [Test]
+    public void AChangeOnlyTouchesWhatItStates()
+    {
+        var before = new ModelProfile
+        {
+            Capabilities = Capability.TEXT_INPUT | Capability.WEB_SEARCH,
+            Reasoning = ReasoningSupport.OPTIONAL,
+            Context = ContextWindow.Of(128_000),
+        };
+
+        var after = new ModelProfileChange { Removes = Capability.WEB_SEARCH }.ApplyTo(before);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(after.Capabilities, Is.EqualTo(Capability.TEXT_INPUT));
+            Assert.That(after.Reasoning, Is.EqualTo(ReasoningSupport.OPTIONAL), "A change saying nothing about reasoning must not reset it.");
+            Assert.That(after.Context, Is.EqualTo(before.Context), "A change saying nothing about the context window must not reset it.");
+        });
+    }
+
+    [Test]
+    public void WhatAChangeTakesAwayWinsOverWhatItAdds()
+    {
+        var change = new ModelProfileChange
+        {
+            Adds = Capability.TEXT_INPUT | Capability.WEB_SEARCH,
+            Removes = Capability.WEB_SEARCH,
+        };
+
+        Assert.That(change.ApplyTo(ModelProfile.UNKNOWN).Capabilities, Is.EqualTo(Capability.TEXT_INPUT));
+    }
+
+    [Test]
+    public void AProfileNeverCarriesTheReasoningVocabulary()
+    {
+        //
+        // The three reasoning members can be combined into answers no model can give, which is why
+        // a profile states reasoning in one field instead. A rule declaring one of them has made a
+        // mistake; that it cannot reach the answer is the second line of defence, not the first.
+        //
+        var change = new ModelProfileChange
+        {
+            Adds = Capability.TEXT_INPUT | Capability.ALWAYS_REASONING,
+            Reasoning = ReasoningSupport.ALWAYS,
+        };
+
+        var profile = change.ApplyTo(ModelProfile.UNKNOWN);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(profile.Capabilities, Is.EqualTo(Capability.TEXT_INPUT));
+            Assert.That(profile.Has(Capability.ALWAYS_REASONING), Is.False);
+            Assert.That(profile.Reasoning, Is.EqualTo(ReasoningSupport.ALWAYS));
+        });
+    }
+}