优化监视器提示

src/utils/observer.ts

@@ -55,7 +55,7 @@ export class Observer {
   // 查询是否注册
   list(type = '') {
     if (!type) {
-      throw new Error(`${type} is not exist`);
+      throw new Error('type is not exist');
     };
     if (this.handle.has(type)) {
       return this.handle.get(type);