NestJS实体类内获取Request对象遇阻，审计字段赋值求助

问题描述 #

开发NestJS小型项目时，需要为实体添加created_by、modified_by这类审计字段，已将用户信息存入Request对象，控制器中可正常获取，但在TypeORM实体的@BeforeInsert、@BeforeUpdate钩子中使用@Req注入Request对象时，得到的是undefined，无法完成用户ID赋值。

原尝试代码 #

import { Req } from "@nestjs/common";
import { Exclude } from "class-transformer";
import { BeforeInsert, BeforeUpdate, Column, CreateDateColumn, DeleteDateColumn, PrimaryGeneratedColumn, UpdateDateColumn } from "typeorm";

export class BaseModel{
    @PrimaryGeneratedColumn('uuid')
    id:string

    @CreateDateColumn()
    created_at:Date

    @Column({default:null})
    created_by:string

    @UpdateDateColumn()
    modified_at:Date

    @Column({default:null})
    modified_by:string

    @DeleteDateColumn({select:false})
    @Exclude()
    deleted_at:Date

    @BeforeInsert()
    setAuditsBeforeInsert(@Req() req:any){
        this.created_by=req.currentUser.id;
        this.modified_by=req.currentUser.id;
    }

    @BeforeUpdate()
    setAuditsBeforeUpdate(@Req() req:any){
        this.modified_by=req.currentUser.id;
    }
} 

问题原因 #

TypeORM的实体生命周期钩子（如@BeforeInsert、@BeforeUpdate）并不处于NestJS的依赖注入上下文范围内，因此无法直接通过@Req装饰器注入Request对象，这就是钩子中req为undefined的核心原因。

解决方案 #

方案一：使用AsyncLocalStorage传递请求上下文（推荐） #

这是NestJS官方推荐的跨层级传递请求上下文的方式，能在实体钩子中直接获取当前请求的用户信息。

1. 创建请求上下文存储
   创建src/common/context/request.context.ts，用于保存和获取当前请求的用户信息：

import { AsyncLocalStorage } from 'async_hooks';

export interface RequestContext {
  userId: string;
}

export const requestContextStorage = new AsyncLocalStorage<RequestContext>();

2. 实现请求上下文拦截器
   创建src/common/interceptors/request-context.interceptor.ts，在请求进入时将用户信息存入上下文存储：

import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '@nestjs/common';
import { Observable } from 'rxjs';
import { requestContextStorage } from '../context/request.context';

@Injectable()
export class RequestContextInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
    const request = context.switchToHttp().getRequest();
    const userId = request.currentUser?.id; // 对应你存入Request的用户ID字段

    return requestContextStorage.run({ userId }, () => next.handle());
  }
}

3. 全局注册拦截器
   在app.module.ts中注册拦截器，让所有请求都经过上下文处理：

import { Module } from '@nestjs/common';
import { APP_INTERCEPTOR } from '@nestjs/core';
import { RequestContextInterceptor } from './common/interceptors/request-context.interceptor';

@Module({
  providers: [
    {
      provide: APP_INTERCEPTOR,
      useClass: RequestContextInterceptor,
    },
  ],
})
export class AppModule {}

4. 修改实体钩子逻辑
   更新BaseModel中的钩子，从上下文存储中获取用户ID：

import { Exclude } from "class-transformer";
import { BeforeInsert, BeforeUpdate, Column, CreateDateColumn, DeleteDateColumn, PrimaryGeneratedColumn, UpdateDateColumn } from "typeorm";
import { requestContextStorage } from './common/context/request.context';

export class BaseModel{
    @PrimaryGeneratedColumn('uuid')
    id:string

    @CreateDateColumn()
    created_at:Date

    @Column({default:null})
    created_by:string

    @UpdateDateColumn()
    modified_at:Date

    @Column({default:null})
    modified_by:string

    @DeleteDateColumn({select:false})
    @Exclude()
    deleted_at:Date

    @BeforeInsert()
    setAuditsBeforeInsert(){
        const context = requestContextStorage.getStore();
        if (context) {
            this.created_by = context.userId;
            this.modified_by = context.userId;
        }
    }

    @BeforeUpdate()
    setAuditsBeforeUpdate(){
        const context = requestContextStorage.getStore();
        if (context) {
            this.modified_by = context.userId;
        }
    }
} 

方案二：使用自定义Repository（手动传递用户ID） #

如果不想用AsyncLocalStorage，也可以通过自定义Repository，在Service层调用时手动传入用户ID。

1. 创建基础Repository

import { Repository } from 'typeorm';

export class BaseRepository<T> extends Repository<T> {
  async createWithAudit(entity: Partial<T>, userId: string): Promise<T> {
    const newEntity = this.create({
      ...entity,
      created_by: userId,
      modified_by: userId,
    });
    return this.save(newEntity);
  }

  async updateWithAudit(id: string | number, entity: Partial<T>, userId: string): Promise<T> {
    await this.update(id, {
      ...entity,
      modified_by: userId,
    });
    return this.findOneBy({ id } as any);
  }
}

2. 实体绑定自定义Repository
   在你的业务实体上指定使用这个基础Repository：

import { Entity } from 'typeorm';
import { BaseModel } from './base.model';
import { BaseRepository } from './base.repository';

@Entity({ repository: () => BaseRepository })
export class User extends BaseModel {
  // 你的业务字段
  @Column()
  username: string;
}

3. Service层调用时传入用户ID
   在Service中从Request获取用户ID，调用自定义Repository的方法：

import { Injectable, Req } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { User } from './user.entity';
import { BaseRepository } from './base.repository';

@Injectable()
export class UserService {
  constructor(
    @InjectRepository(User)
    private readonly userRepository: BaseRepository<User>,
  ) {}

  async createUser(@Req() req, userData: Partial<User>) {
    return this.userRepository.createWithAudit(userData, req.currentUser.id);
  }
}

内容的提问来源于stack exchange，提问作者user20181423