code: function toJSON (str) {
    str = str.toString();
    try {
      return JSON.parse(str);
    } catch (e) {
      throw new Error(
        'The "toJSON" helper must be passed a valid JSON string.'
      );
    }
  }
docs: Converts a string to JSON; useful when used in helper sub-expressions.
  
  @since v0.0.1
  @param {String} str
  @return {Array|Object}
  @example
  {{#each (toJSON '[1,2,3]')}}{{this}}{{/each}} //=> '123'