index.js

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global.ifEmoji = factory());
}(this, function () { 'use strict';

  var _ArrayLikeToString = function _ArrayLikeToString(arg) {
    return Array.prototype.toString.call(arg);
  };

  var getTextFeature = function getTextFeature(text, color) {
    try {
      var canvas = document.createElement('canvas');
      canvas.width = 1;
      canvas.height = 1;

      var ctx = canvas.getContext('2d');
      ctx.textBaseline = 'top';
      ctx.font = '100px -no-font-family-here-';
      ctx.fillStyle = color;
      ctx.scale(0.01, 0.01);
      ctx.fillText(text, 0, 0);

      return ctx.getImageData(0, 0, 1, 1).data;
    } catch (e) {
      return false;
    }
  };

  var compareFeatures = function compareFeatures(feature1, feature2) {
    var feature1Str = _ArrayLikeToString(feature1);
    var feature2Str = _ArrayLikeToString(feature2);
    return feature1Str === feature2Str && feature1Str !== '0,0,0,0';
  };

  function index (text) {
    var feature1 = getTextFeature(text, '#000');
    var feature2 = getTextFeature(text, '#fff');
    return feature1 && feature2 && compareFeatures(feature1, feature2);
  }

  return index;

}));