grunt-concat separator option?

Question

how to specify a separator in this scenario:
I'm concatenating my files with grunt-concat this way:

concat: {
  options: {
    banner: '<%= banner %>',
    separator: ""
  },
  dist: {
    files:{
      '<%= distdir %>/public/scripts/ieditor.js': [
        'public/scripts/ieditor/vars.js',
        'public/scripts/ieditor/controllers/*.js',
        'public/scripts/ieditor/directives/*.js',
        'public/scripts/ieditor/app.js',
        'public/scripts/ieditor/services/*.js',
        'public/scripts/ieditor/filters/*.js'
      ],
      '<%= distdir %>/public/scripts/dashboard.js': [
        'public/scripts/dashboard/vars.js',
        'public/scripts/dashboard/controllers/*.js',
        'public/scripts/dashboard/directives/*.js',
        'public/scripts/dashboard/app.js',
        'public/scripts/dashboard/services/*.js',
        'public/scripts/dashboard/filters/*.js'
      ]
    }
  }
}

what I want is to get a final result mapped to the original files like in compass when concatenating CSS files.
Example:

//####public/scripts/ieditor/vars.js###############
content of public/scripts/ieditor/vars.js
//####public/scripts/ieditor/controllers/a.js######
content of public/scripts/ieditor/controllers/a.js
//####public/scripts/ieditor/controllers/b.js######
content of public/scripts/ieditor/controllers/b.js
.....

So what's the name referring to the current file being concatenated so i can do something like this in the options area:

  options: {
    banner: '<%= banner %>',
    separator: "<%= current_file_name %>"
  },

Thanks in advance.

Answer 1

The process option, specified as a function, is your friend:

concat: {
  options: {
    process: function(src, filepath) {
      return '//####' + filepath + '\n' + src;
    }
  }
},
...