index.js
function messageFormat (type, inspect) {
  var msg = this.detailed
    ? 'expect %s `%s`, but %s `%s` given'
    : 'expect `%s`, but `%s` given'
  return this.detailed
    ? util.format(msg, type.expected, inspect.expected, type.actual, inspect.actual)
    : util.format(msg, type.expected, type.actual)
}
function messageFormat (type, inspect) {
  var msg = this.detailed
    ? 'expect %s `%s`, but %s `%s` given'
    : 'expect `%s`, but `%s` given'
  return this.detailed
    ? util.format(msg, type.expected, inspect.expected, type.actual, inspect.actual)
    : util.format(msg, type.expected, type.actual)
}
function messageFormat ( type , inspect ) { var msg = this . detailed ? 'expect %s `%s`, but %s `%s` given' : 'expect `%s`, but `%s` given' return this . detailed ? util . format ( msg , type . expected , inspect . expected , type . actual , inspect . actual ) : util . format ( msg , type . expected , type . actual ) }
> Default message formatting function.

@param  {Object} `type`
@param  {Object} `inspect`
@return {String}
> Default message formatting function .