Strip drag drop test (#30754)

* Add test for drag drop to open strip menu

* Make screencoords change based on deadzone

Content.IntegrationTests/Tests/Strip/StrippableTest.cs

@@ -0,0 +1,46 @@
+using Content.Client.Interaction;
+using Content.IntegrationTests.Tests.Interaction;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Input;
+using Robust.Shared.Map;
+
+namespace Content.IntegrationTests.Tests.Strip;
+
+public sealed class StrippableTest : InteractionTest
+{
+    protected override string PlayerPrototype => "MobHuman";
+
+    [Test]
+    public async Task DragDropOpensStrip()
+    {
+        // Spawn one tile away
+        TargetCoords = SEntMan.GetNetCoordinates(new EntityCoordinates(MapData.MapUid, 1, 0));
+        await SpawnTarget("MobHuman");
+
+        var userInterface = Comp<UserInterfaceComponent>(Target);
+        Assert.That(userInterface.Actors.Count == 0);
+
+        // screenCoordinates diff needs to be larger than DragDropSystem._deadzone
+        var screenX = CEntMan.System<DragDropSystem>().Deadzone + 1f;
+
+        // Start drag
+        await SetKey(EngineKeyFunctions.Use,
+            BoundKeyState.Down,
+            TargetCoords,
+            Target,
+            screenCoordinates: new ScreenCoordinates(screenX, 0f, WindowId.Main));
+
+        await RunTicks(5);
+
+        // End drag
+        await SetKey(EngineKeyFunctions.Use,
+            BoundKeyState.Up,
+            PlayerCoords,
+            Player,
+            screenCoordinates: new ScreenCoordinates(0f, 0f, WindowId.Main));
+
+        await RunTicks(5);
+
+        Assert.That(userInterface.Actors.Count > 0);
+    }
+}