Add test of disposal unit throw-insert behavior (#39479)

* Add test of disposal unit throw-insert behavior

* Remove initially-empty check

Content.IntegrationTests/Tests/Disposal/DisposalUnitInteractionTest.cs

@@ -0,0 +1,54 @@
+using Content.IntegrationTests.Tests.Interaction;
+using Content.Server.Containers;
+using Robust.Shared.Containers;
+using Robust.Shared.Prototypes;
+
+namespace Content.IntegrationTests.Tests.Disposal;
+
+public sealed class DisposalUnitInteractionTest : InteractionTest
+{
+    private static readonly EntProtoId DisposalUnit = "DisposalUnit";
+    private static readonly EntProtoId TrashItem = "BrokenBottle";
+
+    private const string TestDisposalUnitId = "TestDisposalUnit";
+
+    [TestPrototypes]
+    private static readonly string TestPrototypes = $@"
+# A modified disposal unit with a 100% chance of a thrown item being inserted
+- type: entity
+  parent: {DisposalUnit.Id}
+  id: {TestDisposalUnitId}
+  components:
+  - type: ThrowInsertContainer
+    probability: 1
+";
+
+    /// <summary>
+    /// Spawns a disposal unit, gives the player a trash item, and makes the
+    /// player throw the item at the disposal unit.
+    /// After a short delay, verifies that the thrown item is contained inside
+    /// the disposal unit.
+    /// </summary>
+    [Test]
+    public async Task ThrowItemIntoDisposalUnitTest()
+    {
+        var containerSys = Server.System<SharedContainerSystem>();
+
+        // Spawn the target disposal unit
+        var disposalUnit = await SpawnTarget(TestDisposalUnitId);
+
+        // Give the player some trash to throw
+        var trash = await PlaceInHands(TrashItem);
+
+        // Throw the item at the disposal unit
+        await ThrowItem();
+
+        // Wait a moment
+        await RunTicks(10);
+
+        // Make sure the trash is in the disposal unit
+        var throwInsertComp = Comp<ThrowInsertContainerComponent>();
+        var container = containerSys.GetContainer(ToServer(disposalUnit), throwInsertComp.ContainerId);
+        Assert.That(container.ContainedEntities, Contains.Item(ToServer(trash)));
+    }
+}