fix(world): remove non-retail portal exit fade

tests/AcDream.App.Tests/Streaming/TeleportTransitCoordinatorTests.cs

@@ -0,0 +1,133 @@
+using AcDream.App.Streaming;
+
+namespace AcDream.App.Tests.Streaming;
+
+public sealed class TeleportTransitCoordinatorTests
+{
+    [Fact]
+    public void ReplacementRejectsDelayedPriorDestinationAndAcceptsCurrentAdvance()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+        Assert.True(transit.QueueStart(10));
+        Assert.False(transit.Activate(out _));
+        transit.EndActive();
+        Assert.True(transit.QueueStart(11));
+        Assert.False(transit.Activate(out _));
+
+        Assert.False(transit.OfferDestination(10, true, 100, out _));
+        Assert.True(transit.OfferDestination(11, true, 110, out int accepted));
+        Assert.Equal(110, accepted);
+    }
+
+    [Fact]
+    public void PositionBeforeF751IsBufferedAndEqualFollowupCannotReplaceIt()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+
+        Assert.False(transit.OfferDestination(11, true, 110, out _));
+        Assert.True(transit.QueueStart(11));
+        Assert.True(transit.Activate(out int buffered));
+        Assert.Equal(110, buffered);
+        Assert.False(transit.OfferDestination(11, false, 111, out _));
+    }
+
+    [Fact]
+    public void InactiveOrdinaryPositionIsNeverBuffered()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+
+        Assert.False(transit.OfferDestination(11, false, 110, out _));
+        Assert.True(transit.QueueStart(11));
+        Assert.False(transit.Activate(out _));
+    }
+
+    [Fact]
+    public void DuplicateStartIsRejectedButSequenceWrapIsFresh()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+        Assert.True(transit.QueueStart(ushort.MaxValue));
+        Assert.False(transit.Activate(out _));
+        transit.EndActive();
+
+        Assert.False(transit.CanBegin(ushort.MaxValue));
+        Assert.False(transit.QueueStart(ushort.MaxValue));
+        Assert.True(transit.CanBegin(0));
+        Assert.True(transit.QueueStart(0));
+        Assert.True(transit.HasPendingStart);
+    }
+
+    [Fact]
+    public void ExactHalfRangeUsesRetailLowerStampTieBreak()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+        Assert.True(transit.QueueStart(0x8000));
+        Assert.False(transit.Activate(out _));
+        transit.EndActive();
+
+        Assert.True(transit.CanBegin(0x0000));
+        Assert.True(transit.QueueStart(0x0000));
+    }
+
+    [Fact]
+    public void ClearSessionAllowsSameSequenceInNewSession()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+        Assert.True(transit.QueueStart(7));
+        Assert.False(transit.Activate(out _));
+
+        transit.ClearSession();
+
+        Assert.False(transit.IsActive);
+        Assert.True(transit.CanBegin(7));
+    }
+
+    [Fact]
+    public void PendingStartAcceptsEqualPositionUntilPresentationCanActivate()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+        Assert.True(transit.QueueStart(11));
+
+        Assert.False(transit.OfferDestination(11, false, 110, out _));
+        Assert.True(transit.Activate(out int buffered));
+
+        Assert.Equal(110, buffered);
+        Assert.True(transit.IsActive);
+    }
+
+    [Fact]
+    public void AdvancingPositionPrunesSkippedDestination()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+
+        Assert.False(transit.OfferDestination(11, true, 110, out _));
+        Assert.False(transit.OfferDestination(12, true, 120, out _));
+        Assert.True(transit.QueueStart(12));
+        Assert.True(transit.Activate(out int buffered));
+
+        Assert.Equal(120, buffered);
+    }
+
+    [Fact]
+    public void ObsoleteDestinationCannotSurviveSequenceWrap()
+    {
+        var transit = new TeleportTransitCoordinator<int>();
+
+        Assert.False(transit.OfferDestination(ushort.MaxValue, true, 999, out _));
+        Assert.False(transit.OfferDestination(0, true, 0, out _));
+        Assert.True(transit.QueueStart(0));
+        Assert.True(transit.Activate(out int wrapped));
+        Assert.Equal(0, wrapped);
+        transit.EndActive();
+
+        // Advance in legal retail-newer hops until 0xFFFF is current again.
+        Assert.True(transit.QueueStart(0x7FFF));
+        Assert.False(transit.Activate(out _));
+        transit.EndActive();
+        Assert.True(transit.QueueStart(0xFFFE));
+        Assert.False(transit.Activate(out _));
+        transit.EndActive();
+        Assert.True(transit.QueueStart(ushort.MaxValue));
+
+        Assert.False(transit.Activate(out _));
+    }
+}