Read the context window from a provider's model list

app/Tests/Settings/ModelProfileChainTests.cs

@@ -1,4 +1,5 @@
 using AIStudio.Models;
+using AIStudio.Models.Live;
 using AIStudio.Provider;
 using AIStudio.Settings;
 using AIStudio.Tests.Models.Corpus;
@@ -10,14 +11,31 @@ namespace AIStudio.Tests.Settings;
 /// </summary>
 /// <remarks>
 /// Behind it stand the links of the chain in the order they win: what a person said about their own
-/// installation, then what the rules worked out, then what the app assumes. The rules themselves are
-/// measured elsewhere, against the whole corpus. What is measured here is the last link -- the one
-/// nothing held to account until now, because a model falling through looked exactly like a model
-/// nobody had asked about.
+/// installation, then what that installation reported about itself, then what the rules worked out,
+/// then what the app assumes. The rules themselves are measured elsewhere, against the whole corpus.
+/// What is measured here is everything around them -- the last link, which nothing held to account
+/// until now because a model falling through looked exactly like a model nobody had asked about,
+/// and the order of the three links above it, each of which can speak about the same number.
+///
+/// What a provider reported lands in the store the app shares, so these tests must not run next to
+/// anything else touching it.
 /// </remarks>
 [TestFixture]
+[NonParallelizable]
 public sealed class ModelProfileChainTests
 {
+    private const string MACHINE = "33333333-3333-3333-3333-333333333333";
+
+    /// <summary>
+    /// A window no rule would ever state, so that finding it proves where the answer came from.
+    /// </summary>
+    private const int WHAT_THE_MACHINE_REPORTS = 33_333;
+
+    private static readonly Model MODEL = new("qwen3-32b", null);
+
+    [SetUp]
+    public void ForgetWhatTheMachineSaidBefore() => ListedModels.Shared.Report(MACHINE, []);
+
     [Test]
     public void EveryModelLeftToTheDefaultIsAnsweredByTheAssumption()
     {
@@ -100,4 +118,71 @@ public sealed class ModelProfileChainTests
             Assert.That(profile.Has(Capability.TEXT_INPUT), Is.True, "Everything nobody said anything about stays as the rules had it.");
         });
     }
+
+    [Test]
+    public void WhatThePersonTypedBeatsWhatTheMachineReported()
+    {
+        //
+        // Somebody who types a window has a reason for it, and the app is not in a position to know
+        // it better -- they may be working around an engine reporting nonsense.
+        //
+        ListedModels.Shared.Report(MACHINE, [new(MODEL.Id, ContextWindow.Of(WHAT_THE_MACHINE_REPORTS))]);
+        var configured = ProviderWith(new() { ContextWindowTokens = 8_192 });
+
+        Assert.That(configured.GetModelProfile().Context.DefaultTokens, Is.EqualTo(8_192));
+    }
+
+    [Test]
+    public void WhatTheMachineReportedBeatsWhatTheRulesWorkedOut()
+    {
+        ListedModels.Shared.Report(MACHINE, [new(MODEL.Id, ContextWindow.Of(WHAT_THE_MACHINE_REPORTS))]);
+        var configured = ProviderWith(null);
+
+        Assert.That(configured.GetModelProfile().Context.DefaultTokens, Is.EqualTo(WHAT_THE_MACHINE_REPORTS));
+    }
+
+    [Test]
+    public void ASilentMachineLeavesTheRulesStanding()
+    {
+        var configured = ProviderWith(null);
+
+        Assert.That(configured.GetModelProfile().Context, Is.EqualTo(LLMProviders.SELF_HOSTED.GetModelProfile(MODEL).Context));
+    }
+
+    [Test]
+    public void TheAutomaticAnswerIsWhatHappensWithoutTheSwitches()
+    {
+        //
+        // This is the number the expert dialog offers as its placeholder. Showing the rules there
+        // while the chat goes by the reported window would tell a person that emptying the field
+        // gets them something it does not.
+        //
+        ListedModels.Shared.Report(MACHINE, [new(MODEL.Id, ContextWindow.Of(WHAT_THE_MACHINE_REPORTS))]);
+        var configured = ProviderWith(new() { ContextWindowTokens = 8_192 });
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(configured.GetAutomaticModelProfile().Context.DefaultTokens, Is.EqualTo(WHAT_THE_MACHINE_REPORTS));
+            Assert.That(configured.GetModelProfile().Context.DefaultTokens, Is.EqualTo(8_192), "What the person typed is still what counts everywhere else.");
+        });
+    }
+
+    [Test]
+    public void WhatOneMachineReportsIsNoAnswerForAnother()
+    {
+        ListedModels.Shared.Report(MACHINE, [new(MODEL.Id, ContextWindow.Of(WHAT_THE_MACHINE_REPORTS))]);
+        var somebodyElse = ProviderWith(null) with { Id = "44444444-4444-4444-4444-444444444444" };
+
+        Assert.That(somebodyElse.GetModelProfile().Context, Is.EqualTo(LLMProviders.SELF_HOSTED.GetModelProfile(MODEL).Context));
+    }
+
+    /// <summary>
+    /// A configured self-hosted provider, the way the settings hold one.
+    /// </summary>
+    /// <param name="overrides">What the person switched, or nothing when they switched nothing.</param>
+    /// <returns>The configured provider.</returns>
+    private static AIStudio.Settings.Provider ProviderWith(ProviderCapabilityOverrides? overrides) => new(1, MACHINE, "A machine of my own", LLMProviders.SELF_HOSTED, MODEL, IsSelfHosted: true)
+    {
+        CapabilityOverrides = overrides,
+    };
 }