handlebars helper repeat. with data slice

repeat.hbs.js

// var _ = require('underscore');
function repeat(n, options) {
      /* jshint validthis: true */
      var isNumber = function(n) {
        var type = typeof(num);
        if (type === 'string') {
          if (!num.trim()) return false;
        } else if (type !== 'number') {
          return false;
        }
        return (num - num + 1) >= 0;
      }

      var hasNumber = isNumber(n);
      var context = {};
      var self = this;

      if (!hasNumber) {
        options = n;
      }

      if (self && self.context) {
        _.extend(self, self.context);
      }

      if (options.hasOwnProperty('hash')) {
        _.extend(options, options.hash);
      }

      if (options.count) {
        n = options.count;
        hasNumber = true;
      }

      _.extend(options, self, context);

      if (hasNumber) {
        return block(options);
      } else {
        console.log('options: ', options);
        return options.inverse(options);
      }

      function block(opts) {
        opts = opts || {};
        var str = '';

        var hash = opts.hash || {};
        hash.start = hash.start || 0;

        for (var i = hash.start; i < n + hash.start; i++) {
          hash.index = i;
          hash.isFirst = i === 0;
          hash.isLast = i === (len - 1);
          str += opts.fn(opts, {data: hash});
        }
        return str;
      }
    }


function foreach(arr,options) {
  if(options.inverse && !arr.length)
    return options.inverse(this);

  return arr.map(function(item,index) {
    item.$index = index;
    item.$first = index === 0;
    item.$last  = index === arr.length-1;
    return options.fn(item);
  }).join('');
}