Added CreateInstanceOnStart attribute

Assets/Pacore/Runtime/ClassAttributeCache.cs

@@ -13,8 +13,8 @@ namespace PashaBibko.Pacore.Runtime
 
         public static ReadOnlyCollection<Type> GetAttributesOf<T>()
         {
-            return AttributeCache.TryGetValue(typeof(T), out List<Type> attributes) ?
-                attributes.AsReadOnly() :
+            return AttributeCache.TryGetValue(typeof(T), out List<Type> classes) ?
+                classes.AsReadOnly() :
                 throw new ArgumentException($"Attribute [{nameof(T)}] is not used by any classes");
         }
 

Assets/Pacore/Runtime/CreateInstanceOnStartLoader.cs

@@ -0,0 +1,33 @@
+using PashaBibko.Pacore.Shared.Attributes;
+using System.Collections.ObjectModel;
+using UnityEngine;
+using System;
+
+using Object = UnityEngine.Object;
+
+namespace PashaBibko.Pacore.Runtime
+{
+    public static class CreateInstanceOnStartLoader
+    {
+        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
+        private static void CreateAllInstances()
+        {
+            /* Fetches all the types with the CreateInstanceOnStart attribute */
+            ReadOnlyCollection<Type> types =
+                ClassAttributeCache.GetAttributesOf<CreateInstanceOnStartAttribute>();
+
+            /* Creates a holder for all the other game objects to not clutter inspector */
+            GameObject holder = new("ScriptSpawnedInstances");
+            Object.DontDestroyOnLoad(holder); // Stops all the game objects from being destroyed
+            
+            Transform parent = holder.transform;
+            
+            /* Creates all the game objects for the selected types */ 
+            foreach (Type type in types)
+            {
+                GameObject go = new(type.Name, type);
+                go.transform.SetParent(parent);
+            }
+        }
+    }
+}

Assets/Pacore/Runtime/CreateInstanceOnStartLoader.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: cc80f2f5d2d545e2a5776a2c7d86a813
+timeCreated: 1769274499

Assets/Pacore/Shared/Attributes/CreateInstanceOnStart.cs

@@ -0,0 +1,8 @@
+using UnityEngine.Scripting;
+using System;
+
+namespace PashaBibko.Pacore.Shared.Attributes
+{
+    [Preserve, AttributeUsage(AttributeTargets.Class)]
+    public class CreateInstanceOnStartAttribute : Attribute { }
+}

Assets/Pacore/Shared/Attributes/CreateInstanceOnStart.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 76e2a7cd34f24a17be15685d89706cd3
+timeCreated: 1769274185

Assets/TestMonoBehaviour.cs

@@ -1,7 +1,7 @@
 using PashaBibko.Pacore.Shared.Attributes;
 using UnityEngine;
 
-public class TestMonoBehaviour : MonoBehaviour
+[CreateInstanceOnStart] public class TestMonoBehaviour : MonoBehaviour
 {
     [InspectorReadOnly, SerializeField] private GameObject go;