nestelia 提供内置异常类，自动生成结构化的错误响应。

内置异常

import {
  HttpException,
  BadRequestException,
  NotFoundException,
  UnauthorizedException,
  ForbiddenException,
} from "nestelia";

用法

从控制器方法或服务中抛出异常：

@Get("/:id")
async findOne(@Ctx() ctx: any) {
  const user = await this.userService.findById(ctx.params.id);
  if (!user) {
    throw new NotFoundException(`User ${ctx.params.id} not found`);
  }
  return user;
}

框架捕获异常并返回：

{
  "statusCode": 404,
  "message": "User 123 not found"
}

HttpException

所有 HTTP 异常的基类：

throw new HttpException("Something went wrong", 500);

// 或使用响应对象
throw new HttpException({ message: "Validation failed", errors: [] }, 422);

便捷异常类

异常	状态码
BadRequestException	400
UnauthorizedException	401
ForbiddenException	403
NotFoundException	404

自定义异常

继承 HttpException 创建自己的异常：

class ValidationException extends HttpException {
  constructor(errors: string[]) {
    super({ message: "Validation failed", errors }, 422);
  }
}

class PaymentRequiredException extends HttpException {
  constructor() {
    super("Payment required", 402);
  }
}

异常过滤器

异常过滤器让你能够拦截并转换全局抛出的异常。

定义过滤器

实现 ExceptionFilter 接口，并使用 @Catch() 指定要处理的异常类型：

import { Catch, ExceptionFilter, ExceptionContext, HttpException } from "nestelia";

@Catch(HttpException)
class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException, context: ExceptionContext) {
    return {
      statusCode: exception.getStatus(),
      message: exception.message,
      timestamp: new Date().toISOString(),
      path: context.path,
    };
  }
}

使用不带参数的 @Catch() 捕获所有错误：

@Catch()
class GlobalExceptionFilter implements ExceptionFilter {
  catch(exception: Error, context: ExceptionContext) {
    const status = exception instanceof HttpException
      ? exception.getStatus()
      : 500;

    return {
      statusCode: status,
      message: exception.message,
      timestamp: new Date().toISOString(),
    };
  }
}

注册过滤器

在根模块的 providers 中使用 APP_FILTER 令牌注册全局异常过滤器：

import { Module, APP_FILTER } from "nestelia";

@Module({
  providers: [
    {
      provide: APP_FILTER,
      useClass: HttpExceptionFilter,
    },
  ],
})
class AppModule {}

ExceptionContext

传递给 catch() 的上下文对象包含：

interface ExceptionContext {
  request: Request;
  response: any;
  set: { status: number; headers: Record<string, string> };
  path: string;
  method: string;
}