uglifier: Uglifier::Error: Unexpected token: punc ((). To use ES6 syntax, harmony mode must be enabled with Uglifier.new(:harmony => true)

Hi, When I run “rake assets:precompile RAILS_ENV=production” command, I have issue. rake assets:precompile RAILS_ENV=production rake aborted! Uglifier::Error: Unexpected token: punc ((). To use ES6 syntax, harmony mode must be enabled with Uglifier.new(:harmony => true). /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/uglifier-4.0.2/lib/uglifier.rb:237:in parse_result' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/uglifier-4.0.2/lib/uglifier.rb:219:in run_uglifyjs’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/uglifier-4.0.2/lib/uglifier.rb:169:in compile' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/uglifier_compressor.rb:53:in call’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/uglifier_compressor.rb:28:in call' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:75:in call_processor’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:57:in block in call_processors' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:56:in reverse_each’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:56:in call_processors' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/loader.rb:134:in load_from_unloaded’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/loader.rb:60:in block in load' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/loader.rb:317:in fetch_asset_from_dependency_cache’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/loader.rb:44:in load' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/cached_environment.rb:20:in block in initialize’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/cached_environment.rb:47:in load' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/base.rb:66:in find_asset’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/base.rb:73:in find_all_linked_assets' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/manifest.rb:142:in block in find’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:114:in block (2 levels) in logical_paths' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:228:in block in stat_tree’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:212:in block in stat_directory' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:209:in each’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:209:in stat_directory' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:227:in stat_tree’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:105:in each' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:105:in block in logical_paths’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:104:in each' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:104:in logical_paths’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/manifest.rb:140:in find' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/sprockets/manifest.rb:185:in compile’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-rails-3.2.1/lib/sprockets/rails/task.rb:68:in block (3 levels) in define' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-3.7.1/lib/rake/sprocketstask.rb:147:in with_logger’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/sprockets-rails-3.2.1/lib/sprockets/rails/task.rb:67:in block (2 levels) in define' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/gems/rake-12.2.1/exe/rake:27:in <top (required)>’ /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/bin/ruby_executable_hooks:15:in eval' /Users/leonverspeek/.rvm/gems/ruby-2.3.1@zombie/bin/ruby_executable_hooks:15:in <main>’ Tasks: TOP => assets:precompile (See full trace by running task with --trace)

How to fix this issue?

About this issue

Original URL
State: closed
Created 7 years ago
Reactions: 42
Comments: 31 (1 by maintainers)

Commits related to this issue

Fix precompile bug https://github.com/lautis/uglifier/issues/127#issuecomment-352224986 — committed to Sinetheta/payment_request_api by Sinetheta 6 years ago
Update config.assets.js_compressor per https://github.com/lautis/uglifier/issues/127. — committed to SplitTime/OpenSplitTime by moveson 6 years ago
Modify config/environments/production.rb uglifier line due to errors (https://github.com/lautis/uglifier/issues/127) — committed to msarit/flixster by deleted user 6 years ago
bugfix https://github.com/lautis/uglifier/issues/127#issuecomment-352224986 — committed to sizer/locateit by sizer 6 years ago
update uglifier per https://github.com/lautis/uglifier/issues/127 — committed to mccollek/data-dictionary by mccollek 6 years ago
uglifier stuff Uglifier.new(harmony: true) https://github.com/lautis/uglifier/issues/127#issuecomment-352224986 — committed to lucfranken/diy10 by lucfranken 6 years ago
Uglifier with harmony (https://github.com/lautis/uglifier/issues/127) — committed to mirelon/prosody_analysis by deleted user 6 years ago
config.assets.js_compressor = Uglifier.new(harmony: true) https://github.com/lautis/uglifier/issues/127 — committed to Koh0214/narou-susume by Koh0214 6 years ago
fix: uglifier: https://github.com/lautis/uglifier/issues/127#issuecomment-352224986 — committed to cihad/teklifal by cihad 6 years ago
jquery test 2 test 2 success. added "Uglifier.new(harmony: true)" to config/environment/production.rb See https://github.com/lautis/uglifier/issues/127 — committed to notoriousgorilla/HydroApp by notoriousgorilla 6 years ago
changing uglifier settings to fix a build issue https://github.com/lautis/uglifier/issues/127 — committed to worknenjoy/truppie by alexanmtz 6 years ago
changing uglifier settings to fix a build issue https://github.com/lautis/uglifier/issues/127 — committed to worknenjoy/truppie by alexanmtz 6 years ago
fix: uglifier: https://github.com/lautis/uglifier/issues/127#issuecomment-352224986 — committed to cihad/teklifal by cihad 6 years ago
Building off last commit, in production.rb, new change... ...to try to cure heroku deployment error. See here: https://github.com/lautis/uglifier/issues/127 — committed to breadoliveoilsalt/garden-tracker by breadoliveoilsalt 6 years ago
Fix Uglifier issue See: https://github.com/lautis/uglifier/issues/127 — committed to picandocodigo/interstate_club by picandocodigo 6 years ago
Update uglifier https://github.com/lautis/uglifier/issues/127 — committed to ChangJoo-Park/rails-stimulus-example by ChangJoo-Park 5 years ago
Call Uglifier.new in production https://github.com/lautis/uglifier/issues/127#issuecomment-352224986 — committed to sharkipedia/sharkipedia by coffeejunk 5 years ago
Fix(prod env): Enable ES6 syntax for asset precompilation Should solve the "Uglifier::Error: Unexpected token: name (input)" error https://github.com/lautis/uglifier/issues/127#issuecomment-352224986... — committed to hpi-swt2/vm-portal by chrisma 5 years ago
cf issue https://github.com/lautis/uglifier/issues/127 to change assets js compressor — committed to CharlesDiGI/plus_de_chatounes by CharlesDiGI 5 years ago
Merge pull request #72 from CharlesDiGI/delivery cf issue https://github.com/lautis/uglifier/issues/127 to change asse… — committed to CharlesDiGI/plus_de_chatounes by CharlesDiGI 5 years ago

Most upvoted comments

Try replacing

config.assets.js_compressor = :uglifier

with

config.assets.js_compressor = Uglifier.new(harmony: true)

in config/environments/production.rb

+1282

abraham on Dec 17, 2017

abraham, you save my day

+77

chengs2416me on Jan 4, 2018

Thank you, that worked! - Is there any reason why I wouldn’t want to enable ES6 syntax or why this feature isn’t on by default?

rgaufman on Jan 19, 2018

@fwolfst Just use a rake task. This only checks the asset pipeline files. You may also want to check your vendor file. I had this issue and found out that eslint was converting a vendor file into es6 syntax.

namespace :javascript do
  desc "Compiles each js file"
  task validate: :environment do
    JS_PATH = "app/assets/javascripts/**/*.js"
    Dir[JS_PATH].each do |file_name|
      puts "\n#{file_name}"
      puts Uglifier.compile(File.read(file_name))
    end
  end
end

humphreyja on Apr 15, 2019

thanks! was using duck duck go to search and couldnt find anything. switched to google and it was on the first page…

AdnanTheExcellent on Jul 10, 2018

Try replacing
config.assets.js_compressor = :uglifier
with
config.assets.js_compressor = Uglifier.new(harmony: true)
in config/environments/production.rb

@abraham You are a superhero.

arefin-zeno on Dec 28, 2018

Try replacing
config.assets.js_compressor = :uglifier
with
config.assets.js_compressor = Uglifier.new(harmony: true)
in config/environments/production.rb
For some reason, this leads to:
rake aborted!
NameError: uninitialized constant Uglifier

Nevermind, this was just a case of missing something as simple as

require 'uglifier' in production.rb

Silly me.

dsignr on Jan 9, 2019

Thanks abraham !

Peskoo on Jan 5, 2018

In case anyone comes here looking for a solution to a similar error:

Uglifier::Error: Unexpected token: keyword (extends)        
--        
  1 import { Controller } from "stimulus"        
  2        
  => export default class extends Controller {

I recommend following this solution and switch to terser-ruby

AxelTheGerman on Feb 15, 2021

Repalced config.assets.js_compressor = :uglifier with

config.assets.js_compressor = Uglifier.new(harmony: true) in config/environments/production.rb

as suggested by @abraham abraham but i am encountering new error after this

Uglifier::Error: Unexpected token punc «;», expected punc «,»

Could you please suggest howto fix.

deepkum on Oct 9, 2018

config.assets.js_compressor = Uglifier.new(harmony: true) didn’t work for me, but I going up 3 release levels from 1.X something it got a lot better. Try going to ‘4.0.2’.

jwmount on Jun 23, 2019

Is there any way to figure out which source JS-file is the culprit? iiuc, the error happens while compressing javascript code, so in theory there should be a solution by cleaning up the code before compression, isnt it?

fwolfst on Mar 28, 2019

I ran into this issue because Prettier was formatting an old jQuery file and adding ES6 syntax. Just throwing this solution in there in case someone gets stuck. Just save the file without Prettier.

gsauzande on May 14, 2019

Repalced config.assets.js_compressor = :uglifier with

config.assets.js_compressor = Uglifier.new(harmony: true) in config/environments/production.rb

as suggested by @abraham abraham but i am encountering new error after this

Uglifier::Error: Unexpected token punc «;», expected punc «,»

I’v got the same issus : Uglifier::Error: Unexpected token: punc (😃 Do you fixed it finally ? Thank you 😃

tommulliez on Dec 11, 2018