Refactor AddContainerToSelectedContainer

src/Components/App/App.tsx

@@ -1,5 +1,5 @@
 import React, { Dispatch, SetStateAction, useCallback, useEffect, useRef, useState } from 'react';
-import { events as EVENTS, UseCustomEvents } from '../../Events/AppEvents';
+import { UseCustomEvents } from '../../Events/AppEvents';
 import { MainMenu } from '../MainMenu/MainMenu';
 import { ContainerModel, IContainerModel } from '../../Interfaces/IContainerModel';
 import { Editor } from '../Editor/Editor';

src/Components/Editor/Actions/AddContainer.ts

@@ -27,21 +27,15 @@ import { SortChildren } from './ContainerOperations';
  */
 export function AddContainerToSelectedContainer(
   type: string,
-  selected: IContainerModel | undefined,
+  selected: IContainerModel,
   configuration: IConfiguration,
   fullHistory: IHistoryState[],
   historyCurrentStep: number
-): IHistoryState[] | null {
-  if (selected === null ||
-    selected === undefined) {
-    return null;
-  }
-
-  const parent = selected;
+): IHistoryState[] {
   return AddContainer(
-    parent.children.length,
+    selected.children.length,
     type,
-    parent.properties.id,
+    selected.properties.id,
     configuration,
     fullHistory,
     historyCurrentStep

src/Components/Editor/Editor.tsx

@@ -140,16 +140,17 @@ export function Editor(props: IEditorProps): JSX.Element {
             historyCurrentStep
           ))}
         addContainer={(type) => {
-          const newHistory = AddContainerToSelectedContainer(
+          if (selected === null || selected === undefined) {
+            return;
+          }
+
+          setNewHistory(AddContainerToSelectedContainer(
             type,
             selected,
             configuration,
             history,
             historyCurrentStep
-          );
-          if (newHistory !== null) {
-            setNewHistory(newHistory);
-          }
+          ));
         }}
         addContainerAt={(index, type, parent) => setNewHistory(
           AddContainer(

src/Events/EditorEvents.ts

@@ -240,20 +240,16 @@ function AppendContainerToSelectedContainer(root: Element | Document,
 
   const selected = FindContainerById(currentState.containers, currentState.selectedContainerId);
 
-  const newHistory = AddContainerToSelectedContainerAction(
+  if (selected !== null && selected !== undefined) {
+    setNewHistory(AddContainerToSelectedContainerAction(
       type,
       selected,
       editorState.configuration,
       history,
       editorState.historyCurrentStep
-  );
-
-  if (newHistory === null) {
-    return;
+    ));
   }
 
-  setNewHistory(newHistory);
-
   const customEvent = new CustomEvent<IHistoryState>(
     'appendContainerToSelectedContainer',
     { detail: structuredClone(editorState.history[editorState.historyCurrentStep]) });