post processing css with ember-cli to work around libsass blocker

index.js

/* eslint-env node */
'use strict';

const path = require('path');
const replace = require('broccoli-replace');
const Merge = require('broccoli-merge-trees');

module.exports = {
  name: 'replacc',

  included: function (app) {
    this._super.included.apply(this, arguments);
  },

  postprocessTree: function (type, tree) {
    if (type !== 'css') { return tree; }

    return replace(tree, {
      files: ['assets/*.css'],
      patterns: [
        {
          match: /rgbx/g,
          replacement: "rgba"
        }
      ]
    });
  }
};