Media Query Matcher. Match a specific breakpoint using Modernizr.mq() (example breakpoints are Bootstrap defaults) – Requires Modernizr, obviously.

Media-Query-Matcher.coffee

class MediaQueries
    breakpoints =
        screenXS:    '(min-width: 480px)'
        screenXSmax: '(max-width: 767px)'
        screenSM:    '(min-width: 768px)'
        screenMD:    '(min-width: 992px)'
        screenLG:    '(min-width: 1200px)'

    errorMsg = 'Invalid or no breakpoint specified.'
    if Object.keys? then errorMsg += " Valid arguments: #{Object.keys(breakpoints)}"

    ###*
     * Match a specific breakpoint using Modernizr.mq()
     * @param  {string} breakpoint Any key from {Object} breakpoints
     * @return {boolean}           true if query matches against the current state of the window
    ###
    match: (breakpoint) =>
        if not breakpoint? or not breakpoints.hasOwnProperty(breakpoint) then throw new Error errorMsg
        Modernizr.mq breakpoints[breakpoint]

    constructor: ->
        if not Modernizr?.mq? then @match = -> throw new Error 'Modernizr is not initialized.'

# Usage:
mq = new MediaQueries()
mq.match 'screenLG' # `true` or `false`

Media-Query-Matcher.js

var MediaQueries, mq,
  __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };

MediaQueries = (function() {
  var breakpoints, errorMsg;

  breakpoints = {
    screenXS:    '(min-width: 480px)',
    screenXSmax: '(max-width: 767px)',
    screenSM:    '(min-width: 768px)',
    screenMD:    '(min-width: 992px)',
    screenLG:    '(min-width: 1200px)'
  };

  errorMsg = 'Invalid or no breakpoint specified.';

  if (Object.keys != null) {
    errorMsg += " Valid arguments: " + (Object.keys(breakpoints));
  }

  /**
   * Match a specific breakpoint using Modernizr.mq()
   * @param  {string} breakpoint Any key from {Object} breakpoints
   * @return {boolean}           true if query matches against the current state of the window
   */
  MediaQueries.prototype.match = function(breakpoint) {
    if ((breakpoint == null) || !breakpoints.hasOwnProperty(breakpoint)) {
      throw new Error(errorMsg);
    }
    return Modernizr.mq(breakpoints[breakpoint]);
  };

  function MediaQueries() {
    this.match = __bind(this.match, this);
    if ((typeof Modernizr !== "undefined" && Modernizr !== null ? Modernizr.mq : void 0) == null) {
      this.match = function() {
        throw new Error('Modernizr is not initialized.');
      };
    }
  }

  return MediaQueries;

})();

// Usage:
mq = new MediaQueries();
mq.match('screenLG'); // `true` or `false`