nestjs对接微信支付退款

nestjs可以通过官方提供的npm包`@nestjs/common`和第三方npm包`wechat-pay-sdk`来对接微信支付退款。

1. 安装`wechat-pay-sdk`和`@nestjs/common`。

npm install wechat-pay-sdk @nestjs/common

2. 创建微信支付退款的服务类。

import { Injectable } from '@nestjs/common';
import { WechatPay } from 'wechat-pay-sdk';

@Injectable()
export class WechatRefundService {
  private wechatPay: WechatPay;

  constructor() {
    this.wechatPay = new WechatPay({
      appid: 'your_appid',
      mchid: 'your_mchid',
      partnerKey: 'your_partnerKey',
      notifyUrl: 'your_notifyUrl',
      pfx: fs.readFileSync('your_pfx_path'),
    });
  }

  async refund(outTradeNo: string, outRefundNo: string, totalFee: number, refundFee: number): Promise<any> {
    const result = await this.wechatPay.refund({
      out_trade_no: outTradeNo,
      out_refund_no: outRefundNo,
      total_fee: totalFee,
      refund_fee: refundFee,
    });
    return result;
  }
}

3. 在需要使用退款服务的地方引入服务类并调用`refund`方法。

import { Controller, Post, Body } from '@nestjs/common';
import { WechatRefundService } from './wechat-refund.service';

@Controller()
export class AppController {
  constructor(private readonly wechatRefundService: WechatRefundService) {}

  @Post('/refund')
  async refund(@Body() body: any): Promise<any> {
    const { outTradeNo, outRefundNo, totalFee, refundFee } = body;
    const result = await this.wechatRefundService.refund(outTradeNo, outRefundNo, totalFee, refundFee);
    return result;
  }
}

以上就是nestjs对接微信支付退款的基本流程，可以根据具体的业务需求进行调整。