Error thrown is Function contains = in argument

[demonmind]

I have a function in javascript that contains = sign in arguments such as the one below

function(arg1=null, arg2=null){
....
}

I get this error

ExecJS::ProgramError: Unexpected token operator «=», expected punc «,»

Any help would be appriciated

[lautis]

UglifyJS currently has very limited support for ES6. mishoo/UglifyJS2#448 contains more information about the status.

It probably would make sense to clarify that Uglifier is due to the underlying library also a ES5 minifier.

[demonmind]

Fixed this by not using uglifyer and switching to Closure