feat(scoreboard): unit 5 — tile selection and the cached strip presenter

ScoreboardTiles decides which of the eight facts appear and shapes their text (money uses the session's dominant currency and flags a second one rather than converting; watch hours carry 'as of {date}' because Analytics is a daily aggregate). Tiles are OPT-IN, so 'None' really means the layer draws nothing, and 'Default' is the six session facts. ScoreboardPresenter owns the raster cache: ScoreboardRecorder.Changed fires only on a visible change, so the strip rebuilds only then — a per-tick raster would be the compositor's most expensive layer for identical pixels. Guard: ScoreboardPresenterTests asserts the cache identity (same instance when nothing moved, a new frame when a value moved, reuse when a recipient-side gift event arrives) and that an empty selection returns no frame at all.
2026-10-30 14:38:59 -07:00
parent fbcccea0f7
commit 41b0cd6e98
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+using System.Threading;
+using Xunit;
+using ytLive.Models;
+using ytLive.Services.Compositor;
+
+namespace ytLive.Tests;
+
+/// <summary>The strip's cache is a performance rule with teeth: it must rebuild when a displayed
+/// value moves and must NOT rebuild otherwise, or the compositor pays for a raster per tick into
+/// pixels that did not change.</summary>
+public class ScoreboardPresenterTests
+{
+    private static ChatMessage Member(string name) => new() { Kind = ChatEventKind.NewMember, AuthorName = name };
+
+    [Fact]
+    public void The_strip_rebuilds_only_when_a_displayed_value_moves()
+    {
+        System.Exception? failure = null;
+        var thread = new Thread(() =>
+        {
+            try
+            {
+                var recorder = new ScoreboardRecorder();
+                var tiles = new ScoreboardTiles
+                {
+                    SuperChats = false, WatchHours = false, Subscribers = false,
+                    NewMembers = true, Milestones = false, LastMember = true,
+                    LastSuperChat = false, LastGift = false,
+                };
+                var presenter = new ScoreboardPresenter(recorder, new ScoreboardStyle());
+                presenter.SetTiles(tiles);
+
+                // Before a session: nothing counted, nothing to draw.
+                Assert.Null(presenter.Frame);
+
+                recorder.StartSession();
+                recorder.Record(Member("First"));
+                var first = presenter.Frame;
+                Assert.NotNull(first);
+
+                // No change: the SAME frame instance comes back (cache hit).
+                Assert.Same(first, presenter.Frame);
+
+                // A visible change: a new frame.
+                recorder.Record(Member("Second"));
+                var second = presenter.Frame;
+                Assert.NotNull(second);
+                Assert.NotSame(first, second);
+
+                // A gift-recipient event changes nothing displayed, so the raster is reused.
+                recorder.Record(new ChatMessage { Kind = ChatEventKind.GiftReceived, AuthorName = "Recipient" });
+                Assert.Same(second, presenter.Frame);
+
+                // Disabling every tile returns no frame, and the layer draws nothing.
+                presenter.SetTiles(ScoreboardTiles.None);
+                Assert.Null(presenter.Frame);
+            }
+            catch (System.Exception ex) { failure = ex; }
+        });
+        thread.SetApartmentState(ApartmentState.STA);
+        thread.Start();
+        thread.Join();
+        Assert.Null(failure);
+    }
+}