fix(search: true interleaving

allstarr.Tests/JellyfinSearchInterleaveTests.cs

@@ -0,0 +1,94 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using allstarr.Controllers;
+
+namespace allstarr.Tests;
+
+public class JellyfinSearchInterleaveTests
+{
+    [Fact]
+    public void InterleaveByScore_PrimaryOnly_PreservesOriginalOrder()
+    {
+        var controller = CreateController();
+        var primary = new List<Dictionary<string, object?>>
+        {
+            CreateItem("zzz filler"),
+            CreateItem("BTS Anthem")
+        };
+
+        var result = InvokeInterleaveByScore(controller, primary, [], "bts", 5.0);
+
+        Assert.Equal(["zzz filler", "BTS Anthem"], result.Select(GetName));
+    }
+
+    [Fact]
+    public void InterleaveByScore_SecondaryOnly_PreservesOriginalOrder()
+    {
+        var controller = CreateController();
+        var secondary = new List<Dictionary<string, object?>>
+        {
+            CreateItem("zzz filler"),
+            CreateItem("BTS Anthem")
+        };
+
+        var result = InvokeInterleaveByScore(controller, [], secondary, "bts", 5.0);
+
+        Assert.Equal(["zzz filler", "BTS Anthem"], result.Select(GetName));
+    }
+
+    [Fact]
+    public void InterleaveByScore_LocalBoost_CanWinCloseHeadToHeadWithoutReorderingSource()
+    {
+        var controller = CreateController();
+        var primary = new List<Dictionary<string, object?>>
+        {
+            CreateItem("luther remastered"),
+            CreateItem("zzz filler")
+        };
+        var secondary = new List<Dictionary<string, object?>>
+        {
+            CreateItem("luther"),
+            CreateItem("yyy filler")
+        };
+
+        var result = InvokeInterleaveByScore(controller, primary, secondary, "luther", 5.0);
+
+        Assert.Equal(["luther remastered", "luther", "zzz filler", "yyy filler"], result.Select(GetName));
+    }
+
+    private static JellyfinController CreateController()
+    {
+        return (JellyfinController)RuntimeHelpers.GetUninitializedObject(typeof(JellyfinController));
+    }
+
+    private static List<Dictionary<string, object?>> InvokeInterleaveByScore(
+        JellyfinController controller,
+        List<Dictionary<string, object?>> primary,
+        List<Dictionary<string, object?>> secondary,
+        string query,
+        double primaryBoost)
+    {
+        var method = typeof(JellyfinController).GetMethod(
+            "InterleaveByScore",
+            BindingFlags.Instance | BindingFlags.NonPublic);
+
+        Assert.NotNull(method);
+
+        return (List<Dictionary<string, object?>>)method!.Invoke(
+            controller,
+            [primary, secondary, query, primaryBoost])!;
+    }
+
+    private static Dictionary<string, object?> CreateItem(string name)
+    {
+        return new Dictionary<string, object?>
+        {
+            ["Name"] = name
+        };
+    }
+
+    private static string GetName(Dictionary<string, object?> item)
+    {
+        return item["Name"]?.ToString() ?? string.Empty;
+    }
+}