fix: Fix UsedItem not being called when you switch items quickly

EXILED/Exiled.Events/EventArgs/Player/UsedItemEventArgs.cs

@@ -28,10 +28,14 @@ public class UsedItemEventArgs : IPlayerEvent, IUsableEvent
         /// <param name="item">
         /// <inheritdoc cref="Item" />
         /// </param>
-        public UsedItemEventArgs(ReferenceHub player, UsableItem item)
+        /// <param name="causedByHolstering">
+        /// <inheritdoc cref="CausedByHolstering"/>
+        /// </param>
+        public UsedItemEventArgs(ReferenceHub player, UsableItem item, bool causedByHolstering)
         {
             Player = Player.Get(player);
-            Usable = Item.Get(item) is Usable usable ? usable : null;
+            Usable = Item.Get(item) as Usable;
+            CausedByHolstering = causedByHolstering;
         }
 
         /// <summary>
@@ -46,5 +50,11 @@ public UsedItemEventArgs(ReferenceHub player, UsableItem item)
         /// Gets the player who used the item.
         /// </summary>
         public Player Player { get; }
+
+        /// <summary>
+        /// Gets a value indicating whether this event was triggered by a player switching items (true) or by waiting after using the item (false).
+        /// </summary>
+        /// <remarks>Use this value if you wish to keep the bug where you could switch items quickly to skip this event.</remarks>
+        public bool CausedByHolstering { get; }
     }
 }

EXILED/Exiled.Events/Handlers/Internal/Round.cs

@@ -42,7 +42,7 @@ namespace Exiled.Events.Handlers.Internal
     internal static class Round
     {
         /// <inheritdoc cref="Handlers.Player.OnUsedItem" />
-        public static void OnServerOnUsingCompleted(ReferenceHub hub, UsableItem usable) => Handlers.Player.OnUsedItem(new (hub, usable));
+        public static void OnServerOnUsingCompleted(ReferenceHub hub, UsableItem usable) => Handlers.Player.OnUsedItem(new (hub, usable, false));
 
         /// <inheritdoc cref="Handlers.Server.OnWaitingForPlayers" />
         public static void OnWaitingForPlayers()

EXILED/Exiled.Events/Patches/Events/Player/UsedItemByHolstering.cs

@@ -0,0 +1,58 @@
+// -----------------------------------------------------------------------
+// <copyright file="UsedItemByHolstering.cs" company="ExMod Team">
+// Copyright (c) ExMod Team. All rights reserved.
+// Licensed under the CC BY-SA 3.0 license.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Exiled.Events.Patches.Events.Player
+{
+    using System.Collections.Generic;
+    using System.Reflection.Emit;
+
+    using Exiled.API.Features;
+    using Exiled.API.Features.Pools;
+    using Exiled.Events.Attributes;
+    using Exiled.Events.EventArgs.Player;
+    using HarmonyLib;
+    using InventorySystem.Items.Usables;
+
+    using static HarmonyLib.AccessTools;
+
+    /// <summary>
+    /// Patches <see cref="Consumable.OnHolstered" />.
+    /// Adds an alternative trigger of the <see cref="Handlers.Player.UsedItem" /> event.
+    /// </summary>
+    [EventPatch(typeof(Handlers.Player), nameof(Handlers.Player.UsedItem))]
+    [HarmonyPatch(typeof(Consumable), nameof(Consumable.OnHolstered))]
+    public class UsedItemByHolstering
+    {
+        private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
+        {
+            List<CodeInstruction> newInstructions = ListPool<CodeInstruction>.Pool.Get(instructions);
+
+            // after ServerRemoveSelf, which lines up with before the ret
+            newInstructions.InsertRange(newInstructions.Count - 2, new CodeInstruction[]
+            {
+                // this.Owner
+                new(OpCodes.Ldarg_0),
+                new(OpCodes.Callvirt, PropertyGetter(typeof(Consumable), nameof(Consumable.Owner))),
+
+                // this (Consumable inherits UsableItem)
+                new(OpCodes.Ldarg_0),
+
+                // true
+                new(OpCodes.Ldc_I4_1),
+
+                // OnUsedItem(new UsedItemEventArgs(ReferenceHub, UsableItem, bool));
+                new(OpCodes.Newobj, Constructor(typeof(UsedItemEventArgs), new[] { typeof(ReferenceHub), typeof(UsableItem), typeof(bool) })),
+                new(OpCodes.Call, Method(typeof(Handlers.Player), nameof(Handlers.Player.OnUsedItem))),
+            });
+
+            for (int z = 0; z < newInstructions.Count; z++)
+                yield return newInstructions[z];
+
+            ListPool<CodeInstruction>.Pool.Return(newInstructions);
+        }
+    }
+}