How to fix @Body() is undefined in NestJS

Issue

My @Body() in my NestJS App seems always to be undefined. I dont use any middleware right now, so I am quite confused how this can happen. Here is my setup:

Controller:

import { Body, Controller, HttpCode, HttpStatus, Post, Req } from "@nestjs/common";
import { AuthService } from './auth.service';

@Controller('api/auth')
export class AuthController {
  constructor(private authService: AuthService) {}

  @HttpCode(HttpStatus.OK)
  @Post('login')
  signIn(@Body() signInDto: Record<string, any>) {
    return this.authService.signIn(signInDto.username, signInDto.password);
  }
}

Here the signInDto is always undefined. Also if I pass the @Req() to the function, it is also undefined..

main.ts:

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { ConfigService } from '@nestjs/config';
import { tenancyMiddleware } from './modules/tenancy/tenancy.middleware';
import { DataSource, getConnection, getManager } from 'typeorm';
import { getTenantConnection } from './modules/tenancy/tenancy.utils';
import { SnakeNamingStrategy } from './snake-naming.strategy';
import { join } from 'path';
import { appDataSource } from './datasource.app';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  // config
  const configService = app.get(ConfigService);
  const port = configService.get<number>('port');
  app.enableCors();

  // Multitenancy
  //app.use(tenancyMiddleware);
  await appDataSource.initialize();
  await appDataSource.runMigrations();
  const schemas = await appDataSource.query(
    'select schema_name as name from information_schema.schemata;',
  );

  for (let i = 0; i < schemas.length; i += 1) {
    const { name: schema } = schemas[i];

    if (schema.startsWith('tenant_')) {
      const tenantId = schema.replace('tenant_', '');
      const connection = await getTenantConnection(tenantId);
      await connection.runMigrations();
      await connection.close();
    }
  }

  await app.listen(port);
}
bootstrap();

Postman Headers:

{
  "accept": "application/json",
  "content-type": "application/json",
  "user-agent": "PostmanRuntime/7.36.1",
  "cache-control": "no-cache",

  "host": "localhost:3000",
  "accept-encoding": "gzip, deflate, br",
  "connection": "keep-alive",
  "content-length": "28"
}

All I found from other questions was to add the content-type header, but it did not fix it. Any hints why my body is always undefined?

Solution

This is a recent "bug" on using multiple versions of reflect-metadata in the project, as discussed here: https://github.com/nestjs/nest/issues/13107

Downgrading typeorm package to 0.3.19 instead of using 0.3.20, should fix that for now.

Answered By - Micael Levi