code: function isTypoTypeof(left, right) {
      if (state.option.notypeof)
        return false;
  
      if (!left || !right)
        return false;
  
      var values = [
        "undefined", "object", "boolean", "number",
        "string", "function", "xml", "object", "unknown"
      ];
  
      if (right.type === "(identifier)" && right.value === "typeof" && left.type === "(string)")
        return !_.contains(values, left.value);
  
      return false;
    }
docs: Checks whether the 'typeof' operator is used with the correct value. For docs on 'typeof' see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof