解决JSON.stringify 方法在序列化 BigInt 类型时的错误

今天学nest时，使用apifox发送请求获取数据，结果还一直报错，而且还是我从未见过的

Do not know how to serialize a BigInt at JSON.stringify (<anonymous>) at stringify，

我都是跟着人家敲的，我就纳闷了，就上网查资料，原来是我的PrismaClient 返回的对象中包含 BigInt 类型的字段，而 JSON.stringify 无法处理 BigInt 类型，从而导致这个错误。

以下是我的代码：

import { Controller, Get, Param } from '@nestjs/common';
import { AppService } from './app.service';
import { PrismaClient } from "@prisma/client"

@Controller()
export class AppController {
  prisma: PrismaClient;

  constructor(private readonly appService: AppService) {
    this.prisma = new PrismaClient()
  }

  @Get(':id')
  async getHello(@Param('id') id: string) {
    const article = await this.prisma.article.findUnique({
      where: {
        id: Number(id)
      }
    });

   
  }
}

这是从数据库的article表中查找id为 1 的数据，它里面有个content的属性，其值有百多来字

解决方法：

1.直接将BigInt 转为string

import { Controller, Get, Param } from '@nestjs/common';
import { AppService } from './app.service';
import { PrismaClient } from "@prisma/client"

@Controller()
export class AppController {
  prisma: PrismaClient;

  constructor(private readonly appService: AppService) {
    this.prisma = new PrismaClient()
  }

  @Get(':id')
  async getHello(@Param('id') id: string) {
    const article = await this.prisma.article.findUnique({
      where: {
        id: Number(id)
      }
    });

   
    if (article) {
      for (const key in article) {
        if (typeof article[key] === 'bigint') {
          article[key] = article[key].toString();
        }
      }
    }

    return article;
  }
}

2.自定义Json.stringify 方法

import { Controller, Get, Param } from '@nestjs/common';
import { AppService } from './app.service';
import { PrismaClient } from "@prisma/client"

@Controller()
export class AppController {
  prisma: PrismaClient;

  constructor(private readonly appService: AppService) {
    this.prisma = new PrismaClient()
  }

  @Get(':id')
  async getHello(@Param('id') id: string) {
    const article = await this.prisma.article.findUnique({
      where: {
        id: Number(id)
      }
    });

    
    const customJSONStringify = (obj: any) => {
      return JSON.stringify(obj, (key, value) =>
        typeof value === 'bigint' ? value.toString() : value
      );
    };

    return JSON.parse(customJSONStringify(article));
  }
}

解决后获取到的数据：