Jekyll configuration to use ES6

[vict0rsch]

I currently have this error because I use ES6:

Configuration file: ./_config.yml
                    Asset caching is disabled by configuration. However, if you're using proxies, a cache might still be created.
                    SyntaxError: Unexpected token: keyword (const)
  Liquid Exception: SyntaxError: Unexpected token: keyword (const) in /_layouts/base.html
rake aborted!
ExecJS::RuntimeError: SyntaxError: Unexpected token: keyword (const)
JS_Parse_Error.get ((execjs):3538:621)
(execjs):4060:48
(execjs):1:40
Object.<anonymous> ((execjs):1:58)
Module._compile (internal/modules/cjs/loader.js:799:30)
Object.Module._extensions..js (internal/modules/cjs/loader.js:810:10)
Module.load (internal/modules/cjs/loader.js:666:32)
tryModuleLoad (internal/modules/cjs/loader.js:606:12)
Function.Module._load (internal/modules/cjs/loader.js:598:3)
Function.Module.runMain (internal/modules/cjs/loader.js:862:12)
/usr/local/lib/ruby/gems/2.5.0/gems/execjs-2.7.0/lib/execjs/external_runtime.rb:39:in `exec'
/usr/local/lib/ruby/gems/2.5.0/gems/execjs-2.7.0/lib/execjs/external_runtime.rb:21:in `eval'
/usr/local/lib/ruby/gems/2.5.0/gems/execjs-2.7.0/lib/execjs/external_runtime.rb:46:in `call'
/usr/local/lib/ruby/gems/2.5.0/gems/uglifier-3.2.0/lib/uglifier.rb:195:in `run_uglifyjs'
/usr/local/lib/ruby/gems/2.5.0/gems/uglifier-3.2.0/lib/uglifier.rb:157:in `compile'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/uglifier_compressor.rb:53:in `call'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/uglifier_compressor.rb:28:in `call'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/processor_utils.rb:75:in `call_processor'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/processor_utils.rb:57:in `block in call_processors'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/processor_utils.rb:56:in `reverse_each'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/processor_utils.rb:56:in `call_processors'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/loader.rb:134:in `load_from_unloaded'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/loader.rb:60:in `block in load'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/loader.rb:317:in `fetch_asset_from_dependency_cache'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/loader.rb:44:in `load'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/cached_environment.rb:20:in `block in initialize'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/cached_environment.rb:47:in `load'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/base.rb:66:in `find_asset'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/base.rb:73:in `find_all_linked_assets'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/manifest.rb:134:in `block in find'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/manifest.rb:133:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/sprockets-3.7.2/lib/sprockets/manifest.rb:133:in `find'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-assets-2.4.0/lib/jekyll/assets/liquid/tag.rb:188:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-assets-2.4.0/lib/jekyll/assets/liquid/tag.rb:188:in `find'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-assets-2.4.0/lib/jekyll/assets/liquid/tag.rb:188:in `_find_asset'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-assets-2.4.0/lib/jekyll/assets/liquid/tag.rb:157:in `find_asset'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-assets-2.4.0/lib/jekyll/assets/liquid/tag.rb:97:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:109:in `render_node'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:88:in `block in render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:75:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:75:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:208:in `block in render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:242:in `with_profiling'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:207:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:220:in `render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:30:in `block (2 levels) in render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:42:in `measure_bytes'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:29:in `block in render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:49:in `measure_time'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:28:in `render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/tags/include.rb:137:in `block in render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/context.rb:123:in `stack'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/tags/include.rb:134:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:109:in `render_node'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:88:in `block in render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:75:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/block_body.rb:75:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:208:in `block in render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:242:in `with_profiling'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:207:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/liquid-4.0.0/lib/liquid/template.rb:220:in `render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:30:in `block (2 levels) in render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:42:in `measure_bytes'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:29:in `block in render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:49:in `measure_time'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/liquid_renderer/file.rb:28:in `render!'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/renderer.rb:123:in `render_liquid'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/renderer.rb:188:in `render_layout'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/renderer.rb:155:in `place_in_layouts'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/renderer.rb:85:in `render_document'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/renderer.rb:62:in `run'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:462:in `block (2 levels) in render_docs'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:460:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:460:in `block in render_docs'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:459:in `each_value'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:459:in `render_docs'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:190:in `render'
/usr/local/lib/ruby/gems/2.5.0/gems/jekyll-3.7.4/lib/jekyll/site.rb:73:in `process'
/Users/victor/Documents/Github/vict0rsch/vict0rsch.github.io/Rakefile:33:in `block in <top (required)>'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `block in execute'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `execute'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:214:in `block in invoke_with_call_chain'
/usr/local/Cellar/ruby/2.5.3_1/lib/ruby/2.5.0/monitor.rb:226:in `mon_synchronize'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:194:in `invoke_with_call_chain'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:238:in `block in invoke_prerequisites'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:236:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:236:in `invoke_prerequisites'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:213:in `block in invoke_with_call_chain'
/usr/local/Cellar/ruby/2.5.3_1/lib/ruby/2.5.0/monitor.rb:226:in `mon_synchronize'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:194:in `invoke_with_call_chain'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/task.rb:183:in `invoke'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:160:in `invoke_task'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:116:in `block (2 levels) in top_level'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:116:in `each'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:116:in `block in top_level'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:125:in `run_with_threads'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:110:in `top_level'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:83:in `block in run'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:186:in `standard_exception_handling'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/lib/rake/application.rb:80:in `run'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.3/exe/rake:27:in `<top (required)>'
/usr/local/lib/ruby/gems/2.5.0/bin/rake:23:in `load'
/usr/local/lib/ruby/gems/2.5.0/bin/rake:23:in `<top (required)>'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli/exec.rb:74:in `load'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli/exec.rb:74:in `kernel_load'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli/exec.rb:28:in `run'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli.rb:424:in `exec'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli.rb:27:in `dispatch'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli.rb:18:in `start'
/usr/local/opt/ruby/bin/bundle:30:in `block in <main>'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/friendly_errors.rb:124:in `with_friendly_errors'
/usr/local/opt/ruby/bin/bundle:22:in `<main>'
Tasks: TOP => publish => generate

I have investigated and found in #137 (comment) a sample config.

This however does not solve my issue.

Here is a sample of my config:

assets:
  dirname: assets
  baseurl: /assets/
  sources:
    - _assets/javascripts
    - _assets/stylesheets
    - _assets/images
    - _assets/fonts
  js_compressor: uglifier
  css_compressor: sass
  cachebust: none
  cache: false
  gzip: [ text/css, application/javascript ]
  debug: false
  compressors:
    uglifier:
      harmony: true
      compress:
        unused: false

with Uglifier 3.2