I can't load this transport in Vercel, neither through relative nor through absolute path

[nemanjam]

In the Readme.md you load transport file via relative path, with Next.js this breaks for me in both local dev environment and Vercel prod:

const logger = pino(
  pino.transport({
    targets: [
      { level: 'debug', target: '../lib/logger.mjs', options }
    ]
  })
)

Absolute path works for me locally but absolute paths are problematic in Vercel and I couldn't get to work there. Here is one such hack to force Vercel to include js file in bundle and reference it through absolute path, but this doesn't work for me:

vercel/next.js#32236 (reply in thread)

Here is my code:

import path from 'node';
import { LoggerOptions, TransportTargetOptions, pino } from 'pino';


const transportAbsolutePath = path.join(process.cwd(), '/lib/transport.mjs');


const targets: TransportTargetOptions[] = [
  { target: 'pino-pretty', level: 'info', options: { colorize: true } },
];

// breaks both locally and in Vercel
const transportRelativePath = '../transport.mjs';

// breaks in Vercel, can't find file on that path
targets.push({ target: transportAbsolutePath, level: 'info', options: {} });


const destination = pino.transport({ targets });

const pinoOptions: LoggerOptions = {
  enabled: true,
  timestamp: pino.stdTimeFunctions.isoTime,
};

export const logger = pino(pinoOptions, destination);

transport.mjs

import { createTransport } from 'pino-slack-transport';

export default createTransport;

I have tried to use CopyWebpackPlugin to include transport.js file in the bundle and reference it by absolute path but again it works locally and breaks in Vercel.

next.config.js

const CopyWebpackPlugin = require('copy-webpack-plugin');

const nextConfig = {
  reactStrictMode: true,
  webpack(config, options) {

    if (options.isServer) {

      config.plugins.push(
        new CopyWebpackPlugin({
          patterns: [
            {
              from: path.join(__dirname, 'lib/logger/transport.mjs'),
              to: path.join(__dirname, '.next/server'),
            },
          ],
        })
      );
    }

    return config;
  },
};

I have also tried to load transport through PinoWebpackPlugin and not through code but it doesn't even compile in dev as soon as I import it.

next.config.js

// it breaks build on this import
const { PinoWebpackPlugin } = require('pino-webpack-plugin');

const nextConfig = {
  reactStrictMode: true,
  webpack(config, options) {

    config.plugins.push(
      new PinoWebpackPlugin({
        transports: [
          'pino-pretty',
          path.join(__dirname, 'lib/logger/transport.mjs'),
        ],
      })
    );

    return config;
  },
};

Do you know some way I can load this transport in Vercel in Next.js app?