ExecJS::ProgramError: Unexpected character '#' when trying to precompile assets for production

Question

I'm trying to compile assets for a Rails 4.1.1 app, using the following command RAILS_ENV=production bundle exec rake assets:precompile but when rails trys to compile the assets it gives me an error.

The error looks like the following,

$ RAILS_ENV=production bundle exec rake assets:precompile
rake aborted!
ExecJS::ProgramError: Unexpected character '#' (line: 13079, col: 0, pos: 361024)

Error
    at new JS_Parse_Error (<eval>:2357:10623)
    at js_error (<eval>:2357:10842)
    at parse_error (<eval>:2357:12560)
    at Object.next_token [as input] (<eval>:2357:17582)
    at next (<eval>:2357:18881)
    at semicolon (<eval>:2357:19726)
    at simple_statement (<eval>:2357:22538)
    at <eval>:2357:20689
    at <eval>:2357:19938
    at <eval>:2357:31926
    at Object.parse (<eval>:2358:98)
  (in /opt/rails/crj.com/app/assets/javascripts/application.js)/home/capin/.gem/ruby/2.1.0/gems/tilt-1.4.1/lib/tilt/template.rb:103:in `render'
/home/capin/.gem/ruby/2.1.0/gems/sprockets-rails-2.1.3/lib/sprockets/rails/task.rb:61:in `block (3 levels) in define'
/home/capin/.gem/ruby/2.1.0/gems/sprockets-rails-2.1.3/lib/sprockets/rails/task.rb:60:in `block (2 levels) in define'
V8::Error: Unexpected character '#'
at js_error (<eval>:2357:10842)
at parse_error (<eval>:2357:12560)
at next_token (<eval>:2357:17582)
at next (<eval>:2357:18881)
at semicolon (<eval>:2357:19726)
at simple_statement (<eval>:2357:22538)
at <eval>:2357:20689
at <eval>:2357:19938
at <eval>:2357:31926
at parse (<eval>:2358:98)
at <eval>:19:24
at <eval>:53:3
/home/capin/.gem/ruby/2.1.0/gems/tilt-1.4.1/lib/tilt/template.rb:103:in `render'
/home/capin/.gem/ruby/2.1.0/gems/sprockets-rails-2.1.3/lib/sprockets/rails/task.rb:61:in `block (3 levels) in define'
/home/capin/.gem/ruby/2.1.0/gems/sprockets-rails-2.1.3/lib/sprockets/rails/task.rb:60:in `block (2 levels) in define'
Tasks: TOP => assets:precompile
(See full trace by running task with --trace)

I tried running the above metioned command with the --trace switch / option, but am a little clueless as to what is causing this error. The project can be viewed in it's entirity here => https://github.com/ipatch/crj.com

Answer 1

demo.js is a JavaScript file, but is using CoffeeScript comments (#) rather than JavaScript comments (//).

Answer 2

It is most probably because rails auto-generated an empty coffescript file for you as part of you generating a controller in you project. You also probably renamed the coffescript to a .js

In the empty js file you'll find auto-generated comments for coffescript which starts with # instead of // used by javascript. Just remove all comments and you're good to go.

EDIT

Since the unexpected '#' character was found on line 13079 of your example then you'll find your comments on that same line.