ForceEditorWriteToDisk.cs

using UnityEditor;
using System;
using UnityEditor.SceneManagement;
using UnityEngine;

[InitializeOnLoad]
public class ForceEditorWriteToDisk {
    private static bool _flushAssets = true;
    private static bool _flushScenes = false;

	static ForceEditorWriteToDisk() {
        Undo.willFlushUndoRecord += FlushToDisk;
        Undo.undoRedoPerformed += FlushToDisk;
        //Undo.postprocessModifications += blah;
    }

    //private static UndoPropertyModification[] blah(UndoPropertyModification[] mods) {
    //    Debug.Log("UndoPropertyModification");
    //    return mods;
    //}

    private static void FlushToDisk() {
        if (_flushAssets) FlushAssetsToDisk();
        if (_flushScenes) FlushScenesToDisk();
    }

    private static void FlushAssetsToDisk() {
        EditorApplication.SaveAssets();
    }

    private static void FlushScenesToDisk() {
        EditorSceneManager.SaveOpenScenes();
    }
}