AGE-334 : export errorHandler for NestJs and fastify

[mw-advait]

• added support for errorHandler function.
• covers express, nestjs and fastify web frameworks.
• will be able to set errorHandler as a wrapper inside global errorHandler

Fastify:

const middleware = require('@middleware.io/node-apm');
const fastify = require('fastify')({ logger: true });

// Register Middleware.io error handler for Fastify
fastify.setErrorHandler((error, request, reply) => {
    middleware.errorHandler(error, request, reply);
    // Optionally, send a response
    reply.status(500).send({ error: error.message });
});

const start = async () => {
    try {
        await fastify.listen({ port: 8080, host: '0.0.0.0' });
        fastify.log.info(`E-commerce app listening at http://0.0.0.0:8080`);
    } catch (err) {
        fastify.log.error(err);
        process.exit(1);
    }
};
start();

Nest.Js

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { errorHandler } from '@middleware.io/node-apm';
import { Catch, ArgumentsHost, ExceptionFilter } from '@nestjs/common';

@Catch()
export class ExpressErrorAdapterFilter implements ExceptionFilter {
  catch(exception: any, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const req = ctx.getRequest();
    const res = ctx.getResponse();
    const next = ctx.getNext();
    // Call your existing Express-style error handler
    errorHandler(exception, req, res, next);
  }
}

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useGlobalFilters(new ExpressErrorAdapterFilter());
  await app.listen(3000);
}
bootstrap();