Abstract class for making reload-proof singletons out of Uniy3D ScriptableObjects

SingletonScriptableObject.cs

using System.Linq;

using UnityEngine;

/// <summary>
/// Abstract class for making reload-proof singletons out of ScriptableObjects
/// Returns the asset created on editor, null if there is none
/// Based on https://www.youtube.com/watch?v=VBA1QCoEAX4
/// </summary>
/// <typeparam name="T">Type of the singleton</typeparam>

public abstract class SingletonScriptableObject<T> : ScriptableObject where T : ScriptableObject
{
	static T _instance = null;
	public static T Instance
	{
		get
		{
			if (!_instance)
				_instance = FindAsset(_instance);
			return _instance;
		}
	}
	/// <summary>
	/// We have to find the asset through AssetDatabase in case the asset is not loaded.
	/// </summary>
	/// <typeparam name="TO"></typeparam>
	/// <param name="typeObject"></param>
	/// <returns></returns>
	public static TO FindAsset<TO>(TO typeObject) where TO : Object
	{

#if UNITY_EDITOR
		if (UnityEditor.EditorPrefs.HasKey(typeof(TO).ToString()))
#else
				if (false)
#endif
		{
#if UNITY_EDITOR
			string objectPath = UnityEditor.EditorPrefs.GetString(typeof(TO).ToString());
			var asset = UnityEditor.AssetDatabase.LoadAssetAtPath(objectPath, typeof(TO)) as TO;

			if (asset == null)
			{
				var assets = UnityEditor.AssetDatabase.FindAssets("t:" + typeof(TO));

				if (assets.Length > 0)
				{
					var assetPath = UnityEditor.AssetDatabase.GUIDToAssetPath(assets[0]);
					var foundAsset = (TO)UnityEditor.AssetDatabase.LoadAssetAtPath(assetPath, typeof(TO));
					UnityEditor.EditorPrefs.SetString(typeof(TO).ToString(), assetPath);

					return foundAsset;

				}


			}
			else
			{
				return asset;
			}
#endif

		}
		else
		{
#if UNITY_EDITOR
			var assets = UnityEditor.AssetDatabase.FindAssets("t:" + typeof(TO));

			if (assets.Length > 0)
			{
				var assetPath = UnityEditor.AssetDatabase.GUIDToAssetPath(assets[0]);
				var foundAsset = (TO)UnityEditor.AssetDatabase.LoadAssetAtPath(assetPath, typeof(TO));
				UnityEditor.EditorPrefs.SetString(typeof(TO).ToString(), assetPath);

				return foundAsset;

			}
#endif
			var asset = Resources.FindObjectsOfTypeAll<TO>().FirstOrDefault();

			if (asset != null)
			{
#if UNITY_EDITOR
				string relPath = UnityEditor.AssetDatabase.GetAssetPath(asset);
				UnityEditor.EditorPrefs.SetString(typeof(TO).ToString(), relPath);
#endif
				return asset;
			}





		}

		return default;
	}
}

Abstract class for making reload-proof singletons out of ScriptableObjects

Returns the asset created on editor, null if there is none
Based on Unite 2017 Video

UPDATE

updated the way the asset is found. I had issues with the asset not loading in the editor and having to select the asset in order for the return value not to be null