LukasMeine / vigilance

//

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

//

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

// NOTE: These type checking functions intentionally don't use `instanceof`

// because it is fragile and can be easily faked with `Object.create()`.

    return Array.isArray(arg);

  }

  return objectToString(arg) === '[object Array]';

}

exports.isArray = isArray;

function isBoolean(arg) {

  return typeof arg === 'boolean';

}

exports.isBoolean = isBoolean;

function isNull(arg) {

  return arg === null;

}

exports.isNull = isNull;

function isNullOrUndefined(arg) {

}

exports.isNullOrUndefined = isNullOrUndefined;

function isNumber(arg) {

  return typeof arg === 'number';

}

exports.isNumber = isNumber;

function isString(arg) {

  return typeof arg === 'string';

}

exports.isString = isString;

function isSymbol(arg) {

  return typeof arg === 'symbol';

}

exports.isSymbol = isSymbol;

function isUndefined(arg) {

}

exports.isUndefined = isUndefined;

function isRegExp(re) {

  return objectToString(re) === '[object RegExp]';

}

exports.isRegExp = isRegExp;

function isObject(arg) {

  return typeof arg === 'object' && arg !== null;

}

exports.isObject = isObject;

function isDate(d) {

  return objectToString(d) === '[object Date]';

}

exports.isDate = isDate;

function isError(e) {

  return (objectToString(e) === '[object Error]' || e instanceof Error);

}

exports.isError = isError;

function isFunction(arg) {

  return typeof arg === 'function';

}

exports.isFunction = isFunction;

  return arg === null ||

         typeof arg === 'boolean' ||

         typeof arg === 'number' ||

         typeof arg === 'string' ||

         typeof arg === 'symbol' ||  // ES6 symbol

         typeof arg === 'undefined';

}

exports.isPrimitive = isPrimitive;

function objectToString(o) {

  return Object.prototype.toString.call(o);

}