TS - unknown vs any

개념
unknown, any 타입을 지정하기 애매할 때 사용

unknown
타입이 뭔지 모르겠으니 개발자가 타입을 정확히 지정주어야 한다.
typeof, instanceof 등 타입을 확인하여 적절한 타입 주입시켜 사용한다.

Example
code reference: https://docs.nestjs.com/exception-filters#catch-everything

@Catch()
export class AllExceptionsFilter implements ExceptionFilter {
  constructor(private readonly httpAdapterHost: HttpAdapterHost) {}

  catch(exception: unknown, host: ArgumentsHost): void {
    const { httpAdapter } = this.httpAdapterHost;
    const ctx = host.switchToHttp();

    const httpStatus =
      exception instanceof HttpException
        ? exception.getStatus()
        : HttpStatus.INTERNAL_SERVER_ERROR;

    const responseBody = {
      statusCode: httpStatus,
      timestamp: new Date().toISOString(),
      path: httpAdapter.getRequestUrl(ctx.getRequest()),
    };

    httpAdapter.reply(ctx.getResponse(), responseBody, httpStatus);
  }
}

 

any
어떠한 타입이 될 수 있으니 자유롭게 사용 가능

참고
https://docs.nestjs.com/exception-filters#catch-everything
https://simsimjae.tistory.com/464

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