uglifier.rb in uglifier-3.2.0

- old
+ new

@@ -10,10 +10,12 @@
   # Error class for compilation errors.
   Error = ExecJS::Error
 
   # UglifyJS source path
   SourcePath = File.expand_path("../uglify.js", __FILE__)
+  # UglifyJS with Harmony source path
+  HarmonySourcePath = File.expand_path("../uglify-harmony.js", __FILE__)
   # Source Map path
   SourceMapPath = File.expand_path("../source-map.js", __FILE__)
   # ES5 shims source path
   ES5FallbackPath = File.expand_path("../es5.js", __FILE__)
   # String.split shim source path
@@ -84,11 +86,12 @@
     }, # Apply transformations to code, set to false to skip
     :define => {}, # Define values for symbol replacement
     :enclose => false, # Enclose in output function wrapper, define replacements as key-value pairs
     :keep_fnames => false, # Generate code safe for the poor souls relying on Function.prototype.name at run-time. Sets both compress and mangle keep_fanems to true.
     :screw_ie8 => false, # Don't bother to generate safe code for IE8
-    :source_map => false # Generate source map
+    :source_map => false, # Generate source map
+    :harmony => false # Enable ES6/Harmony mode (experimental). Disabling mangling and compressing is recommended with Harmony mode.
   }
 
   LEGACY_OPTIONS = [:comments, :squeeze, :copyright, :mangle]
 
   MANGLE_PROPERTIES_DEFAULTS = {
@@ -133,11 +136,13 @@
   def initialize(options = {})
     (options.keys - DEFAULTS.keys - LEGACY_OPTIONS)[0..1].each do |missing|
       raise ArgumentError, "Invalid option: #{missing}"
     end
     @options = options
-    @context = ExecJS.compile(uglifyjs_source)
+
+    source = @options[:harmony] ? source_with(HarmonySourcePath) : source_with(SourcePath)
+    @context = ExecJS.compile(source)
   end
 
   # Minifies JavaScript code
   #
   # @param source [IO, String] valid JS source code.
@@ -162,11 +167,11 @@
     run_uglifyjs(source, true)
   end
 
   private
 
-  def uglifyjs_source
-    [ES5FallbackPath, SplitFallbackPath, SourceMapPath, SourcePath,
+  def source_with(path)
+    [ES5FallbackPath, SplitFallbackPath, SourceMapPath, path,
      UglifyJSWrapperPath].map do |file|
       File.open(file, "r:UTF-8", &:read)
     end.join("\n")
   end
 