add globalThis.ContextType

src/background.js

@@ -16,6 +16,8 @@ import { sendTabMsg } from "./libs/msg";
 import { trySyncAllSubRules } from "./libs/subRules";
 import { tryClearCaches } from "./libs";
 
+globalThis.ContextType = "BACKGROUND";
+
 /**
  * 插件安装
  */

src/libs/browser.js

@@ -13,3 +13,5 @@ function _browser() {
 }
 
 export const browser = _browser();
+
+export const isBg = () => globalThis?.ContextType === "BACKGROUND";