Read the context window from a provider's model list

app/Tests/Models/Live/ListedModelsTests.cs

@@ -0,0 +1,154 @@
+using AIStudio.Models;
+using AIStudio.Models.Live;
+using AIStudio.Provider;
+
+namespace AIStudio.Tests.Models.Live;
+
+/// <summary>
+/// Checks what a running installation is allowed to say about the models it serves.
+/// </summary>
+/// <remarks>
+/// Every test here builds its own store rather than using the shared one. What a provider reported
+/// is state which outlives a single question, and a test leaving some of it behind would decide
+/// what the next test sees.
+/// </remarks>
+[TestFixture]
+public sealed class ListedModelsTests
+{
+    private const string ONE_MACHINE = "11111111-1111-1111-1111-111111111111";
+    private const string ANOTHER_MACHINE = "22222222-2222-2222-2222-222222222222";
+    private const string MODEL = "qwen3-32b";
+
+    /// <summary>
+    /// A model the rules have something to say about, so that a report has something to contradict.
+    /// </summary>
+    private static readonly ModelProfile WHAT_THE_RULES_SAY = new()
+    {
+        Capabilities = Capability.TEXT_INPUT | Capability.TEXT_OUTPUT | Capability.MULTIPLE_IMAGE_INPUT,
+        Kind = ModelKind.CHAT,
+        Context = ContextWindow.Of(131_072, 262_144),
+        Images = new(null, 20),
+    };
+
+    [Test]
+    public void AMachineWhichWasNeverAskedSaysNothing()
+    {
+        var listed = new ListedModels();
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(listed.Of(ONE_MACHINE, MODEL), Is.EqualTo(ModelListing.NOTHING));
+            Assert.That(listed.Of(ONE_MACHINE, MODEL).IsKnown, Is.False);
+        });
+    }
+
+    [Test]
+    public void WhatOneMachineSaysIsNotWhatAnotherSays()
+    {
+        //
+        // The same weights behind two engines, each started by somebody who decided for themselves.
+        // This is the whole reason these numbers are kept per configured instance.
+        //
+        var listed = new ListedModels();
+        listed.Report(ONE_MACHINE, [new(MODEL, ContextWindow.Of(32_768))]);
+        listed.Report(ANOTHER_MACHINE, [new(MODEL, ContextWindow.Of(8_192))]);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(listed.Of(ONE_MACHINE, MODEL).Context.DefaultTokens, Is.EqualTo(32_768));
+            Assert.That(listed.Of(ANOTHER_MACHINE, MODEL).Context.DefaultTokens, Is.EqualTo(8_192));
+        });
+    }
+
+    [Test]
+    public void WhatAMachineNoLongerServesStopsAnswering()
+    {
+        var listed = new ListedModels();
+        listed.Report(ONE_MACHINE, [new(MODEL, ContextWindow.Of(32_768)), new("gemma3-27b", ContextWindow.Of(16_384))]);
+        listed.Report(ONE_MACHINE, [new("gemma3-27b", ContextWindow.Of(16_384))]);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(listed.Of(ONE_MACHINE, MODEL), Is.EqualTo(ModelListing.NOTHING), "The engine was restarted without it, so nothing is known about it any more.");
+            Assert.That(listed.Of(ONE_MACHINE, "gemma3-27b").Context.DefaultTokens, Is.EqualTo(16_384));
+        });
+    }
+
+    [Test]
+    public void AMachineWhichHalvedItsWindowIsBelievedTheSecondTimeToo()
+    {
+        var listed = new ListedModels();
+        listed.Report(ONE_MACHINE, [new(MODEL, ContextWindow.Of(32_768))]);
+        listed.Report(ONE_MACHINE, [new(MODEL, ContextWindow.Of(16_384))]);
+
+        Assert.That(listed.Of(ONE_MACHINE, MODEL).Context.DefaultTokens, Is.EqualTo(16_384));
+    }
+
+    [TestCase("Qwen3-32B")]
+    [TestCase("qwen3-32b")]
+    public void AModelSomebodyTypedIsStillTheSameModel(string asConfigured)
+    {
+        //
+        // An organization writes the model of a provider into its configuration plugin by hand,
+        // and the availability check already treats such a name as the same model whatever case it
+        // was typed in. Being stricter here would leave exactly those people without the numbers.
+        //
+        var listed = new ListedModels();
+        listed.Report(ONE_MACHINE, [new("qwen3-32b", ContextWindow.Of(32_768))]);
+
+        Assert.That(listed.Of(ONE_MACHINE, asConfigured).Context.DefaultTokens, Is.EqualTo(32_768));
+    }
+
+    [Test]
+    public void AnInstanceWithoutAnIdIsNothingToRemember()
+    {
+        var listed = new ListedModels();
+        listed.Report(string.Empty, [new(MODEL, ContextWindow.Of(32_768))]);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(listed.Of(string.Empty, MODEL), Is.EqualTo(ModelListing.NOTHING));
+            Assert.That(listed.Of(ONE_MACHINE, MODEL), Is.EqualTo(ModelListing.NOTHING), "One nameless report does not become every machine's answer.");
+        });
+    }
+
+    [Test]
+    public void AModelTheMachineSaidNothingAboutIsNotStored()
+    {
+        var listed = new ListedModels();
+        listed.Report(ONE_MACHINE, [new(MODEL, ContextWindow.UNKNOWN), new(string.Empty, ContextWindow.Of(32_768))]);
+
+        Assert.That(listed.Of(ONE_MACHINE, MODEL), Is.EqualTo(ModelListing.NOTHING));
+    }
+
+    [Test]
+    public void AReportedWindowReplacesTheWholeWindow()
+    {
+        var after = new ModelListing(MODEL, ContextWindow.Of(32_768)).ApplyTo(WHAT_THE_RULES_SAY);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(after.Context.DefaultTokens, Is.EqualTo(32_768));
+            Assert.That(after.Context.RaisableToTokens, Is.Null, "What the weights could be raised to is not a number anybody reaches without restarting this engine.");
+        });
+    }
+
+    [Test]
+    public void AWindowSaysNothingAboutAnythingElse()
+    {
+        var after = new ModelListing(MODEL, ContextWindow.Of(32_768)).ApplyTo(WHAT_THE_RULES_SAY);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(after.Capabilities, Is.EqualTo(WHAT_THE_RULES_SAY.Capabilities));
+            Assert.That(after.Images, Is.EqualTo(WHAT_THE_RULES_SAY.Images));
+            Assert.That(after.Kind, Is.EqualTo(WHAT_THE_RULES_SAY.Kind));
+        });
+    }
+
+    [Test]
+    public void SayingNothingKeepsEverythingTheRulesWorkedOut()
+    {
+        Assert.That(ModelListing.NOTHING.ApplyTo(WHAT_THE_RULES_SAY), Is.EqualTo(WHAT_THE_RULES_SAY));
+    }
+}