Why can't I get chapter 7 code to run?

srexi

I'm trying to follow along in Chapter 7 "Converting a CJS Package to an ESM Package (1)". I'm running the commands along the tutorial to let stuff sink in, but I can't get 'npm start' to run with the source code I have.

I attached the source and the debug log.

guillermotti

It happened to me also.

I changed the code and it worked. Here is the code:

import * as format from './format.js'
 
const isMain = process.argv[1]
 
if (isMain) {
    const {
        default: pino
    } = await import('pino')
    const logger = pino()
    logger.info(format.upper('my-package started'))
    process.stdin.resume()
}
 
export default (str) => {
    return format.upper(str).split('').reverse().join('')
}

guillermotti

I found the error without removing those lines (url. preceding to fileURLToPath):

import { realpath } from 'fs/promises'
import url from 'url'
import * as format from './format.js'
 
const isMain = process.argv[1] &&
 await realpath(url.fileURLToPath(import.meta.url)) ===
 await realpath(process.argv[1])
 
if (isMain) {
  const { default: pino } = await import('pino')
  const logger = pino()
  logger.info(format.upper('my-package started'))
  process.stdin.resume()
}
 
export default (str) => {
  return format.upper(str).split('').reverse().join('')
}

srexi

That did it. Good eye. Thank you guillermotti

d.m.c

thanks @guillermotti - good catch, material is being updated (just going to do import { fileURLToPath } from 'url' since url is only imported for that function)

fcioanca

This has been corrected. Thank you!