it always good to have some standardized coding rules

use jshint, JSHint and .etc to create auto checker based on these rules

indentation 2 spaces indentation type tab

• refer to usejsdoc
• put 'use strict'; on top.
• use single qoute for string.
• function brackets put as the sample below.
• no restrict on having space after =
• use flow to check javascript input type, (more details).

/**
 * @flow
 * @param {Object} arg1 - user credentials.
 * @param {boolean} arg2 - login for 1 month.
 * @return boolean
 */
function test(arg1, arg2) {
  var string = 'test string'; // sample of string defination
  var username = arg1.username,
      password = arg1.password;
  var login=
    that.login(username, password, function(data){
      return data.result;
    });
  return login;
}

• no "..." + "..." allowed in code when writing sql statement