NestJS GraphQL中RegisterDto参数为空问题求助

定义了RegisterDto和LoginDto两个DTO，LoginDto在登录Resolver中能正常接收参数，但RegisterDto在注册Mutation中无法正常通过验证，执行注册请求时抛出Bad Request错误。

相关代码如下：

DTO代码 #

export class RegisterDto {
  @Field()
  @IsNotEmpty({ message: 'Fullname is required' })
  @IsString({ message: 'Fullname must be a string' })
  fullname: string;

  @Field()
  @IsNotEmpty({ message: 'Password is required' })
  @MinLength(8, { message: 'Fullname must be a string' })
  password: string;

  // @Field()
  // @IsNotEmpty({ message: 'Confirm Password is required' })
  // confirmPassword: string;

  @Field()
  @IsNotEmpty({ message: 'Email is required' })
  @IsEmail({}, { message: 'Fullname must be a string' })
  email: string;
}

export class LoginDto {
  @Field()
  @IsNotEmpty({ message: 'Email is required' })
  @IsEmail({}, { message: 'Email must be valid' })
  email: string;

  @Field()
  @IsNotEmpty({ message: 'Email is required' })
  password: string;
}

登录Resolver代码 #

@Mutation(() => User)
async login(
  @Args('loginInput') loginDto: LoginDto,
  @Context() context: { req: Request; res: Response },
) {
  return this.authService.login(loginDto, context.res); 
}

注册Resolver代码 #

@Mutation(() => User)
async register(
  @Args('registerDto') registerDto: RegisterDto,
  @Context() context: { req: Request; res: Response },
) {
  const { user } = await this.authService.register(registerDto, context.res);
  return { user };
}

执行的注册Mutation #

mutation {
  register(registerDto:{email:"asd",fullname:"asd",password:"asd"}){
    fullname
  }
}

抛出的错误 #

"originalError": {
          "message": [
            "Fullname must be a string",
            "Fullname must be a string"
          ],
          "error": "Bad Request",
          "statusCode": 400
        }

1. 修正验证规则的错误提示信息 #

RegisterDto存在复制粘贴导致的提示信息混淆问题，这会干扰错误排查：

• password字段的@MinLength提示错误写成了Fullname must be a string，应改为Password must be at least 8 characters long
• email字段的@IsEmail提示错误也写成了Fullname must be a string，应改为Email must be a valid email address

修正后的RegisterDto：

export class RegisterDto {
  @Field()
  @IsNotEmpty({ message: 'Fullname is required' })
  @IsString({ message: 'Fullname must be a string' })
  fullname: string;

  @Field()
  @IsNotEmpty({ message: 'Password is required' })
  @MinLength(8, { message: 'Password must be at least 8 characters long' })
  password: string;

  @Field()
  @IsNotEmpty({ message: 'Email is required' })
  @IsEmail({}, { message: 'Email must be a valid email address' })
  email: string;
}

2. 修正请求参数的合法性 #

当前执行的Mutation参数不符合验证规则：

• email:"asd"不是有效邮箱格式，需改为规范格式（如asd@example.com）
• password:"asd"长度仅3位，不符合@MinLength(8)要求，需改为至少8位的密码

修正后的Mutation示例：

mutation {
  register(registerDto:{email:"asd@example.com",fullname:"asd",password:"asd12345"}){
    fullname
  }
}

3. 修正Resolver返回值类型不匹配问题 #

注册Resolver定义的返回类型是User，但代码返回的是{ user }（包含user属性的对象），会导致GraphQL类型校验失败，需直接返回user对象：

@Mutation(() => User)
async register(
  @Args('registerDto') registerDto: RegisterDto,
  @Context() context: { req: Request; res: Response },
) {
  const { user } = await this.authService.register(registerDto, context.res);
  return user;
}

4. 修正LoginDto的错误提示（可选） #

LoginDto中password字段的@IsNotEmpty提示写成了Email is required，建议一并修正：

export class LoginDto {
  @Field()
  @IsNotEmpty({ message: 'Email is required' })
  @IsEmail({}, { message: 'Email must be valid' })
  email: string;

  @Field()
  @IsNotEmpty({ message: 'Password is required' })
  password: string;
}

内容的提问来源于stack exchange，提问作者MiguelG