Added opt-in sharing of feature usage with self-hosted servers (#1020)

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

app/Tests/Tools/AppUserAgentTests.cs

@@ -0,0 +1,105 @@
+using System.Net.Http.Headers;
+
+using AIStudio.Chat;
+using AIStudio.Provider;
+using AIStudio.Settings;
+using AIStudio.Tools;
+
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace AIStudio.Tests.Tools;
+
+/// <summary>
+/// Checks the User-Agent which AI Studio sends to self-hosted servers.
+/// </summary>
+/// <remarks>
+/// Operators of a gateway such as LiteLLM read it in their logs to see which assistant or agent sent a
+/// request. It has to stay a valid header value whatever a plugin calls its assistant, because an
+/// invalid one would either break the request or silently vanish from the logs. Who receives it at all
+/// is a privacy question: nobody without the consent of the user, and a cloud provider never.
+/// </remarks>
+[TestFixture]
+public sealed class AppUserAgentTests
+{
+    [TestCase(LLMProviders.SELF_HOSTED)]
+    [TestCase(LLMProviders.LITE_LLM)]
+    public void ASelfHostedServerReceivesItOnlyWhenSharingIsOn(LLMProviders provider)
+    {
+        var settingsManager = CreateSettingsManager();
+        Assert.That(AppUserAgent.IsAllowedFor(provider, settingsManager), Is.False, "Sharing is off by default, so not even a self-hosted server may learn anything.");
+
+        settingsManager.ConfigurationData.App.ShareFeatureUsageWithSelfHostedServerOperators = true;
+        Assert.That(AppUserAgent.IsAllowedFor(provider, settingsManager), Is.True);
+    }
+
+    [Test]
+    public void NoOtherProviderEverReceivesIt()
+    {
+        var settingsManager = CreateSettingsManager();
+        settingsManager.ConfigurationData.App.ShareFeatureUsageWithSelfHostedServerOperators = true;
+
+        //
+        // Listed by exclusion on purpose: a provider added later falls on the safe side, and whoever
+        // wants it to receive the User-Agent has to change this test and say why.
+        //
+        foreach (var provider in Enum.GetValues<LLMProviders>().Except([LLMProviders.SELF_HOSTED, LLMProviders.LITE_LLM]))
+            Assert.That(AppUserAgent.IsAllowedFor(provider, settingsManager), Is.False, $"The provider {provider} must never learn which feature sent a request.");
+    }
+
+    [Test]
+    public void TheBaseNamesTheApp()
+    {
+        Assert.That(AppUserAgent.BASE, Does.StartWith("MindWorkAIStudio/"));
+        Assert.That(ProductInfoHeaderValue.TryParse(AppUserAgent.BASE.Split(' ')[0], out _), Is.True);
+    }
+
+    [Test]
+    public void ABuiltInComponentIsNamedByItsEnumValue()
+    {
+        var userAgent = AppUserAgent.ForComponent(AIStudio.Tools.Components.TRANSLATION_ASSISTANT);
+        Assert.That(userAgent, Is.EqualTo($"{AppUserAgent.BASE} Component/TRANSLATION_ASSISTANT"));
+    }
+
+    [Test]
+    public void NoComponentKeepsTheBase()
+    {
+        Assert.That(AppUserAgent.ForComponent(AIStudio.Tools.Components.NONE), Is.EqualTo(AppUserAgent.BASE));
+    }
+
+    [TestCase("Übersetzung für Straßen", "Ubersetzung-fur-Strassen")]
+    [TestCase("  My (cool) Assistant/v2  ", "My-cool-Assistant-v2")]
+    [TestCase("already_valid-name.1", "already_valid-name.1")]
+    [TestCase("日本語", "")]
+    public void APluginNameBecomesAValidProductToken(string pluginName, string expectedToken)
+    {
+        var userAgent = AppUserAgent.ForComponent(AIStudio.Tools.Components.DYNAMIC_ASSISTANT, pluginName);
+        var expected = string.IsNullOrEmpty(expectedToken)
+            ? $"{AppUserAgent.BASE} Component/DYNAMIC_ASSISTANT"
+            : $"{AppUserAgent.BASE} Component/DYNAMIC_ASSISTANT Assistant/{expectedToken}";
+
+        Assert.That(userAgent, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void ARequestHeaderReplacesTheDefault()
+    {
+        using var request = new HttpRequestMessage();
+        request.Headers.UserAgent.ParseAdd(AppUserAgent.BASE);
+
+        AppUserAgent.ApplyComponent(request.Headers, new ChatThread { RuntimeComponent = AIStudio.Tools.Components.EMAIL_ASSISTANT });
+
+        Assert.That(request.Headers.UserAgent.ToString(), Is.EqualTo($"{AppUserAgent.BASE} Component/EMAIL_ASSISTANT"));
+        Assert.That(request.Headers.UserAgent.Count, Is.EqualTo(3), "The header must still parse as product, platform comment, and component.");
+    }
+
+    [Test]
+    public void AThreadWithoutAComponentDoesNotCountAsChat()
+    {
+        using var request = new HttpRequestMessage();
+        AppUserAgent.ApplyComponent(request.Headers, new ChatThread());
+
+        Assert.That(request.Headers.UserAgent.ToString(), Is.EqualTo(AppUserAgent.BASE), "A thread whose sender forgot to name its component must not be counted as chat, nor as anything else.");
+    }
+
+    private static SettingsManager CreateSettingsManager() => new(NullLogger<SettingsManager>.Instance, null!);
+}

app/Tests/Tools/ToolCalling/ClassicRagStandsBackTests.cs

@@ -69,5 +69,8 @@ public sealed class ClassicRagStandsBackTests : ToolRegistryTestBase
     private static ChatThread ThreadSearching(DataSourceRetrievalMode preference) => new()
     {
         DataSourceOptions = new() { DisableDataSources = false, AutomaticDataSourceSelection = true, RetrievalMode = preference },
+
+        // A thread names no component until its sender does, and the chat does so before every message:
+        RuntimeComponent = AIStudio.Tools.Components.CHAT,
     };
 }