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

app/Tests/Models/Plugins/DeclaredModelsTests.cs

@@ -0,0 +1,180 @@
+using AIStudio.Models;
+using AIStudio.Models.Matching;
+using AIStudio.Models.Plugins;
+using AIStudio.Models.Registry;
+using AIStudio.Provider;
+
+namespace AIStudio.Tests.Models.Plugins;
+
+/// <summary>
+/// Checks where what an organization declares stands against what AI Studio works out itself.
+/// </summary>
+/// <remarks>
+/// Each test builds a registry of its own rather than asking the one the app uses. What is being
+/// checked is the order of the chain, and a test which had to name a real model to check it would
+/// start failing the day somebody corrects that model's rule.
+///
+/// The one exception borrows the registry the app uses, because only that one knows the hosts. It
+/// hands it back empty, and the fixture is kept out of any parallel run so that the borrowing
+/// cannot reach a test asking the same registry about a real model.
+/// </remarks>
+[TestFixture]
+[NonParallelizable]
+public sealed class DeclaredModelsTests
+{
+    private static readonly Guid PLUGIN_ID = new("11111111-1111-1111-1111-111111111111");
+
+    [Test]
+    public void WhatAnOrganizationDeclaresComesBeforeWhatTheRulesWorkOut()
+    {
+        var registry = ModelRegistry.Build([new AcmeFamily()], []);
+        registry.Declare([Declaring("acme-assistant", MatchKind.PREFIX, Capability.TEXT_INPUT | Capability.TEXT_OUTPUT | Capability.MULTIPLE_IMAGE_INPUT)]);
+
+        var profile = registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-7b");
+
+        Assert.That(profile.Has(Capability.MULTIPLE_IMAGE_INPUT), Is.True, "Only the organization says this model reads images, and they are the ones running it.");
+    }
+
+    [Test]
+    public void ADeclarationIsTheWholeStatementAndNotAnAdditionToOne()
+    {
+        //
+        // The part an administrator has to be able to rely on. Their entry says what the model can
+        // do, so what AI Studio would have said instead is gone -- including the capabilities their
+        // entry does not mention. Adding to the built-in answer would make it impossible to take
+        // anything away, which is exactly what somebody correcting us is trying to do.
+        //
+        var registry = ModelRegistry.Build([new AcmeFamily()], []);
+        registry.Declare([Declaring("acme-assistant", MatchKind.PREFIX, Capability.TEXT_INPUT | Capability.TEXT_OUTPUT)]);
+
+        var profile = registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-7b");
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(profile.Has(Capability.FUNCTION_CALLING), Is.False, "The built-in rule grants this one, and the declaration does not.");
+            Assert.That(profile.Reasoning, Is.EqualTo(ReasoningSupport.NONE), "Nor does it reason, whatever the built-in rule says.");
+        });
+    }
+
+    [Test]
+    public void AModelNoDeclarationMentionsIsAnsweredByTheRulesAsBefore()
+    {
+        var registry = ModelRegistry.Build([new AcmeFamily()], []);
+        registry.Declare([Declaring("something-else", MatchKind.SEGMENT, Capability.TEXT_INPUT)]);
+
+        var profile = registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-7b");
+
+        Assert.That(profile.Has(Capability.FUNCTION_CALLING), Is.True);
+    }
+
+    [Test]
+    public void TakingADeclarationAwayBringsTheBuiltInAnswerBack()
+    {
+        //
+        // This is what happens when an organization withdraws a configuration, or when somebody
+        // corrects their plugin and the plugins are reloaded. It is also the test that the kept
+        // answers are dropped along with the declarations they were worked out under: a cache which
+        // outlived them would go on answering with what a plugin said which is no longer there.
+        //
+        var registry = ModelRegistry.Build([new AcmeFamily()], []);
+        registry.Declare([Declaring("acme-assistant", MatchKind.PREFIX, Capability.TEXT_INPUT | Capability.TEXT_OUTPUT)]);
+
+        var whileDeclared = registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-7b");
+        registry.Declare([]);
+        var afterwards = registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-7b");
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(whileDeclared.Has(Capability.FUNCTION_CALLING), Is.False);
+            Assert.That(afterwards.Has(Capability.FUNCTION_CALLING), Is.True);
+        });
+    }
+
+    [Test]
+    public void AmongTheDeclarationsTheOneSayingMoreAboutTheNameWins()
+    {
+        //
+        // Two plugins, or one plugin describing a family and then one of its variants. Nothing new
+        // is needed for this: the declarations go through the same engine as the built-in rules, so
+        // the specificity is computed here too and nobody writes an order.
+        //
+        var registry = ModelRegistry.Build([new AcmeFamily()], []);
+        registry.Declare(
+        [
+            Declaring("acme-assistant", MatchKind.PREFIX, Capability.TEXT_INPUT | Capability.TEXT_OUTPUT),
+            Declaring("acme-assistant-7b", MatchKind.EXACT, Capability.TEXT_INPUT | Capability.TEXT_OUTPUT | Capability.MULTIPLE_IMAGE_INPUT),
+        ]);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-7b").Has(Capability.MULTIPLE_IMAGE_INPUT), Is.True);
+            Assert.That(registry.Profile(LLMProviders.SELF_HOSTED, "acme-assistant-3b").Has(Capability.MULTIPLE_IMAGE_INPUT), Is.False);
+        });
+    }
+
+    [Test]
+    public void ADeclarationIsMeasuredAgainstTheNameWithoutTheProvidersWrapping()
+    {
+        //
+        // An administrator writes the model's name, not the name plus whatever the gateway they
+        // reach it through puts in front of it. Unwrapping happens before anything is asked, so the
+        // same entry answers whichever way the model is reached.
+        //
+        var registry = ModelRegistry.Shared;
+        var declaration = Declaring("gpt-5.1", MatchKind.PREFIX, Capability.TEXT_INPUT | Capability.TEXT_OUTPUT | Capability.VIDEO_INPUT);
+
+        try
+        {
+            registry.Declare([declaration]);
+
+            Assert.Multiple(() =>
+            {
+                Assert.That(registry.Profile(LLMProviders.OPEN_AI, "gpt-5.1").Has(Capability.VIDEO_INPUT), Is.True);
+                Assert.That(registry.Profile(LLMProviders.OPEN_ROUTER, "openai/gpt-5.1").Has(Capability.VIDEO_INPUT), Is.True, "The same model, reached through a gateway which wraps the name.");
+            });
+        }
+        finally
+        {
+            //
+            // The registry the app uses is the only one which knows the hosts, so this test has to
+            // borrow it. Handing it back empty is what keeps the borrowing from reaching the tests
+            // which ask it about real models.
+            //
+            registry.Declare([]);
+        }
+    }
+
+    private static ModelDeclaration Declaring(string pattern, MatchKind matchKind, Capability capabilities) => new()
+    {
+        Pattern = new()
+        {
+            Kind = matchKind,
+            Text = pattern,
+        },
+
+        Change = new()
+        {
+            Adds = capabilities,
+        },
+
+        Source = new("https://intranet.invalid/ai", new DateOnly(2026, 9, 12), "What a company says about its own models."),
+        Origin = "Models of a company",
+        EnterpriseConfigurationPluginId = PLUGIN_ID,
+    };
+
+    /// <summary>
+    /// A family which says more about these models than the declarations of this test do.
+    /// </summary>
+    private sealed class AcmeFamily : ModelFamily
+    {
+        public override ModelVendor Vendor => ModelVendor.UNKNOWN;
+
+        public override ModelSource Source => new("https://example.invalid/acme", new DateOnly(2026, 9, 12), "A family standing in for whatever AI Studio knows by itself.");
+
+        protected override void Declare(ModelFamilyBuilder builder) =>
+            builder.Rule("acme-assistant").AsPrefix()
+                .Capabilities(Capability.TEXT_INPUT | Capability.TEXT_OUTPUT | Capability.FUNCTION_CALLING)
+                .Apis(Capability.CHAT_COMPLETION_API)
+                .Reasoning(ReasoningSupport.ALWAYS);
+    }
+}