Nest.JS使用拦截器处理response数据格式

统一请求成功的返回数据

1、创建拦截器

npx nest g in interceptor/transform

2、拦截器代码

import {
  Injectable,
  NestInterceptor,
  CallHandler,
  ExecutionContext,
} from '@nestjs/common';
import { map } from 'rxjs/operators';
import { Observable } from 'rxjs';
interface Response<T> {
  data: T;
}
@Injectable()
export class TransformInterceptor<T> implements NestInterceptor<T, Response<T>> {
  intercept(context: ExecutionContext,next: CallHandler<T>,): Observable<Response<T>> {
    return next.handle().pipe(map(data => {
        return {
          data,
          code: 0,
          message: '请求成功',
        };
      }),
    );
  }
}

3、在main.ts中全局注册

import { Logger, ValidationPipe } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import {TransformInterceptor} from './transform.interceptor'

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useGlobalPipes(new ValidationPipe())
  app.useGlobalInterceptors(new TransformInterceptor())
  await app.listen(3000,() => {
    Logger.log('服务已经启动，请访问localhost:3000')
  });
}
bootstrap();