使用数据转换拦截器，这个感觉可以用来统一数据字段啥的，毕竟仅靠人为控制，不够绝对可控

src/core/interceptors/transform.interceptor.ts

@@ -1,9 +1,18 @@
 import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '@nestjs/common';
 import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+
+export interface Response<T>{
+  data: T;
+}
 
 @Injectable()
-export class TransformInterceptor implements NestInterceptor {
-  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
-    return next.handle();
+export class TransformInterceptor<T> implements NestInterceptor<T, Response<T>> {
+  intercept(context: ExecutionContext, next: CallHandler): Observable<Response<T>> {
+    return next
+    .handle()
+    .pipe(
+      map(item => ({data: item}))  // 这个map和js那个map貌似还是有点不一样，那边返回的是一个数组呀？
+    );
   }
 }

src/modules/posts/posts.controller.ts

@@ -5,6 +5,7 @@ import { DemoFilter } from '../../core/filters/demo.filter'
 import { DemoAuthGuard } from '../../core/guards/demo-auth.guard'
 import { Roles } from '../../core/decorators/roles.decorator'
 import { LoggingInterceptor } from '../../core/interceptors/logging.interceptor'
+import { TransformInterceptor } from '../../core/interceptors/transform.interceptor'
 
 @Controller('posts')
 // @UseGuards(DemoAuthGuard)
@@ -15,6 +16,7 @@ export class PostsController {
     constructor(private readonly demoService: DemoService) {}
 
     @Get()
+    @UseInterceptors(TransformInterceptor)
     index() {
         return this.demoService.findAll();
     }