Uncaught ReferenceError when trying to change js function into coffeescript

Question

This is the error:

Uncaught ReferenceError: er is not defined

This is the code ..

{CompositeDisposable} = require 'atom'
lib = require 'lib'

module.exports =
  subscriptions: null

  activate: ->
    @subscriptions = new CompositeDisposable
    @subscriptions.add atom.commands.add 'atom-workspace',
      'my-package:convert': => @convert()

  deactivate: ->
    @subscriptions.dispose()

  convert: ->
    console.log 'Convert text!'
    if editor = atom.workspace.getActiveTextEditor()
      console.log editor.getText()
      lib.process(editor.getText() (er files)) ->
        console.log 'All files ..'
        listFiles(files)

  listFiles: (files) ->
    for fileName in Object.keys(files)
      first = files[fileName].first
      second = files[fileName].second
      third = files[fileName].third
      console.log 'Done'

This is the javascript I'm trying to change to coffeescript inside convert() ..

lib.process(text, function (er, files) {
  console.log('All files ..');
  listFiles(files);
});

Answer 1

The line

lib.process(editor.getText() (er files)) ->

is not correct, since it's missing the commas needed to separate the parameters.

When trying to transpile the line you wrote to JS it would look like this:

lib.process(editor.getText()(er(files)))(function() {});

When trying to migrate JS to coffee, it's sometimes a good idea to start with http://js2.coffee/ and start from there. Always look at the transpiled JS result in order to check if everything will work as expected