ExecJS::ProgramError: Unexpected token punc «(», expected punc «:» when running rake assets:precompile on production

Question

When deploying my Rails app I get the following error:

rake aborted!
   ExecJS::ProgramError: Unexpected token punc «(», expected punc «:» (line: 15, col: 14         


        

Answer 1

If Radovan's answer isn't working for you due to a problem in a library instead of your code, you can try upgrading Uglifier and enabling ES6 compilation.

Gemfile.lock

gem 'uglifier', '~> 4.1'

config/environments/production.rb

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