Use LiteralUnion in EditorEvent

src/common/index.ts

@@ -1,6 +1,8 @@
 import Backbone from 'backbone';
 export { default as $ } from '../utils/cash-dom';
 
+interface NOOP {}
+
 export type Debounced = Function & { cancel(): void };
 
 export type SetOptions = Backbone.ModelSetOptions & { avoidStore?: boolean };
@@ -17,6 +19,9 @@ export type ObjectAny = Record<string, any>;
 
 export type ObjectStrings = Record<string, string>;
 
+// https://github.com/microsoft/TypeScript/issues/29729#issuecomment-1483854699
+export type LiteralUnion<T, U> = T | (U & NOOP);
+
 export type Position = {
   x: number;
   y: number;

src/editor/index.ts

@@ -60,7 +60,7 @@ import BlockManager, { BlockEvent } from '../block_manager';
 import CanvasModule, { CanvasEvent } from '../canvas';
 import CodeManagerModule from '../code_manager';
 import CommandsModule, { CommandEvent } from '../commands';
-import { EventHandler } from '../common';
+import { EventHandler, LiteralUnion } from '../common';
 import CssComposer from '../css_composer';
 import CssRule from '../css_composer/model/CssRule';
 import CssRules from '../css_composer/model/CssRules';
@@ -98,7 +98,9 @@ export type ParsedRule = {
   params?: string;
 };
 
-type EditorEvent =
+type GeneralEvent = 'canvasScroll' | 'undo' | 'redo' | 'load' | 'update';
+
+type EditorBuiltInEvents =
   | ComponentEvent
   | BlockEvent
   | AssetEvent
@@ -110,10 +112,9 @@ type EditorEvent =
   | RichTextEditorEvent
   | ModalEvent
   | CommandEvent
-  | GeneralEvent
-  | string;
+  | GeneralEvent;
 
-type GeneralEvent = 'canvasScroll' | 'undo' | 'redo' | 'load' | 'update';
+type EditorEvent = LiteralUnion<EditorBuiltInEvents, string>;
 
 type EditorConfigType = EditorConfig & { pStylePrefix?: string };