// http://wiki.commonjs.org/wiki/Unit_Testing/1.0
//
// THIS IS NOT TESTED NOR LIKELY TO WORK OUTSIDE V8!
//
// Copyright (c) 2011 Jxck
//
// Originally from node.js (http://nodejs.org)
// Copyright Joyent, Inc.
//
// 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 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.

(function(root, factory) {
  if (typeof define === 'function' && define.amd) {
    define([], factory); // AMD
  } else if (typeof exports === 'object') {
    module.exports = factory(); // CommonJS
  } else {
    root.assert = factory(); // Global
  }
})(this, function() {

// UTILITY

// Object.create compatible in IE
var create = Object.create || function(p) {
  if (!p) throw Error('no type');
  function f() {};
  f.prototype = p;
  return new f();
};

// UTILITY
var util = {
  inherits: function(ctor, superCtor) {
    ctor.super_ = superCtor;
    ctor.prototype = create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  },
  isArray: function(ar) {
    return Array.isArray(ar);
  },
  isBoolean: function(arg) {
    return typeof arg === 'boolean';
  },
  isNull: function(arg) {
    return arg === null;
  },
  isNullOrUndefined: function(arg) {
    return arg == null;
  },
  isNumber: function(arg) {
    return typeof arg === 'number';
  },
  isString: function(arg) {
    return typeof arg === 'string';
  },
  isSymbol: function(arg) {
    return typeof arg === 'symbol';
  },
  isUndefined: function(arg) {
    return arg === undefined;
  },
  isRegExp: function(re) {
    return util.isObject(re) && util.objectToString(re) === '[object RegExp]';
  },
  isObject: function(arg) {
    return typeof arg === 'object' && arg !== null;
  },
  isDate: function(d) {
    return util.isObject(d) && util.objectToString(d) === '[object Date]';
  },
  isError: function(e) {
    return isObject(e) &&
      (objectToString(e) === '[object Error]' || e instanceof Error);
  },
  isFunction: function(arg) {
    return typeof arg === 'function';
  },
  isPrimitive: function(arg) {
    return arg === null ||
      typeof arg === 'boolean' ||
      typeof arg === 'number' ||
      typeof arg === 'string' ||
      typeof arg === 'symbol' ||  // ES6 symbol
      typeof arg === 'undefined';
  },
  objectToString: function(o) {
    return Object.prototype.toString.call(o);
  }
};

var pSlice = Array.prototype.slice;

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
var Object_keys = typeof Object.keys === 'function' ? Object.keys : (function() {
  var hasOwnProperty = Object.prototype.hasOwnProperty,
      hasDontEnumBug = !({ toString: null }).propertyIsEnumerable('toString'),
      dontEnums = [
        'toString',
        'toLocaleString',
        'valueOf',
        'hasOwnProperty',
        'isPrototypeOf',
        'propertyIsEnumerable',
        'constructor'
      ],
      dontEnumsLength = dontEnums.length;

  return function(obj) {
    if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) {
      throw new TypeError('Object.keys called on non-object');
    }

    var result = [], prop, i;

    for (prop in obj) {
      if (hasOwnProperty.call(obj, prop)) {
        result.push(prop);
      }
    }

    if (hasDontEnumBug) {
      for (i = 0; i < dontEnumsLength; i++) {
        if (hasOwnProperty.call(obj, dontEnums[i])) {
          result.push(dontEnums[i]);
        }
      }
    }
    return result;
  };
})();

// 1. The assert module provides functions that throw
// AssertionError's when particular conditions are not met. The
// assert module must conform to the following interface.

var assert = ok;

// 2. The AssertionError is defined in assert.
// new assert.AssertionError({ message: message,
//                             actual: actual,
//                             expected: expected })

assert.AssertionError = function AssertionError(options) {
  this.name = 'AssertionError';
  this.actual = options.actual;
  this.expected = options.expected;
  this.operator = options.operator;
  if (options.message) {
    this.message = options.message;
    this.generatedMessage = false;
  } else {
    this.message = getMessage(this);
    this.generatedMessage = true;
  }
  var stackStartFunction = options.stackStartFunction || fail;
  if (Error.captureStackTrace) {
    Error.captureStackTrace(this, stackStartFunction);
  } else {
    // try to throw an error now, and from the stack property
    // work out the line that called in to assert.js.
    try {
      this.stack = (new Error).stack.toString();
    } catch (e) {}
  }
};

// assert.AssertionError instanceof Error
util.inherits(assert.AssertionError, Error);

function replacer(key, value) {
  if (util.isUndefined(value)) {
    return '' + value;
  }
  if (util.isNumber(value) && (isNaN(value) || !isFinite(value))) {
    return value.toString();
  }
  if (util.isFunction(value) || util.isRegExp(value)) {
    return value.toString();
  }
  return value;
}

function truncate(s, n) {
  if (util.isString(s)) {
    return s.length < n ? s : s.slice(0, n);
  } else {
    return s;
  }
}

function getMessage(self) {
  return truncate(JSON.stringify(self.actual, replacer), 128) + ' ' +
         self.operator + ' ' +
         truncate(JSON.stringify(self.expected, replacer), 128);
}

// At present only the three keys mentioned above are used and
// understood by the spec. Implementations or sub modules can pass
// other keys to the AssertionError's constructor - they will be
// ignored.

// 3. All of the following functions must throw an AssertionError
// when a corresponding condition is not met, with a message that
// may be undefined if not provided.  All assertion methods provide
// both the actual and expected values to the assertion error for
// display purposes.

function fail(actual, expected, message, operator, stackStartFunction) {
  throw new assert.AssertionError({
    message: message,
    actual: actual,
    expected: expected,
    operator: operator,
    stackStartFunction: stackStartFunction
  });
}

// EXTENSION! allows for well behaved errors defined elsewhere.
assert.fail = fail;

// 4. Pure assertion tests whether a value is truthy, as determined
// by !!guard.
// assert.ok(guard, message_opt);
// This statement is equivalent to assert.equal(true, !!guard,
// message_opt);. To test strictly for the value true, use
// assert.strictEqual(true, guard, message_opt);.

function ok(value, message) {
  if (!value) fail(value, true, message, '==', assert.ok);
}
assert.ok = ok;

// 5. The equality assertion tests shallow, coercive equality with
// ==.
// assert.equal(actual, expected, message_opt);

assert.equal = function equal(actual, expected, message) {
  if (actual != expected) fail(actual, expected, message, '==', assert.equal);
};

// 6. The non-equality assertion tests for whether two objects are not equal
// with != assert.notEqual(actual, expected, message_opt);

assert.notEqual = function notEqual(actual, expected, message) {
  if (actual == expected) {
    fail(actual, expected, message, '!=', assert.notEqual);
  }
};

// 7. The equivalence assertion tests a deep equality relation.
// assert.deepEqual(actual, expected, message_opt);

assert.deepEqual = function deepEqual(actual, expected, message) {
  if (!_deepEqual(actual, expected)) {
    fail(actual, expected, message, 'deepEqual', assert.deepEqual);
  }
};

function _deepEqual(actual, expected) {
  // 7.1. All identical values are equivalent, as determined by ===.
  if (actual === expected) {
    return true;

  //  } else if (util.isBuffer(actual) && util.isBuffer(expected)) {
  //    if (actual.length != expected.length) return false;
  //
  //    for (var i = 0; i < actual.length; i++) {
  //      if (actual[i] !== expected[i]) return false;
  //    }
  //
  //    return true;
  //
  // 7.2. If the expected value is a Date object, the actual value is
  // equivalent if it is also a Date object that refers to the same time.
  } else if (util.isDate(actual) && util.isDate(expected)) {
    return actual.getTime() === expected.getTime();

  // 7.3 If the expected value is a RegExp object, the actual value is
  // equivalent if it is also a RegExp object with the same source and
  // properties (`global`, `multiline`, `lastIndex`, `ignoreCase`).
  } else if (util.isRegExp(actual) && util.isRegExp(expected)) {
    return actual.source === expected.source &&
           actual.global === expected.global &&
           actual.multiline === expected.multiline &&
           actual.lastIndex === expected.lastIndex &&
           actual.ignoreCase === expected.ignoreCase;

  // 7.4. Other pairs that do not both pass typeof value == 'object',
  // equivalence is determined by ==.
  } else if (!util.isObject(actual) && !util.isObject(expected)) {
    return actual == expected;

  // 7.5 For all other Object pairs, including Array objects, equivalence is
  // determined by having the same number of owned properties (as verified
  // with Object.prototype.hasOwnProperty.call), the same set of keys
  // (although not necessarily the same order), equivalent values for every
  // corresponding key, and an identical 'prototype' property. Note: this
  // accounts for both named and indexed properties on Arrays.
  } else {
    return objEquiv(actual, expected);
  }
}

var isArguments = function(object) {
  return Object.prototype.toString.call(object) == '[object Arguments]';
};

(function() {
  if (!isArguments(arguments)) {
    isArguments = function(object) {
      return object != null &&
        typeof object === 'object' &&
        typeof object.callee === 'function' &&
        typeof object.length === 'number' || false;
    };
  }
})();

function objEquiv(a, b) {
  if (util.isNullOrUndefined(a) || util.isNullOrUndefined(b))
    return false;
  // an identical 'prototype' property.
  if (a.prototype !== b.prototype) return false;
  //~~~I've managed to break Object.keys through screwy arguments passing.
  //   Converting to array solves the problem.
  var aIsArgs = isArguments(a),
      bIsArgs = isArguments(b);
  if ((aIsArgs && !bIsArgs) || (!aIsArgs && bIsArgs))
    return false;
  if (aIsArgs) {
    a = pSlice.call(a);
    b = pSlice.call(b);
    return _deepEqual(a, b);
  }
  try {
    var ka = Object_keys(a),
        kb = Object_keys(b),
        key, i;
  } catch (e) {//happens when one is a string literal and the other isn't
    return false;
  }
  // having the same number of owned properties (keys incorporates
  // hasOwnProperty)
  if (ka.length != kb.length)
    return false;
  //the same set of keys (although not necessarily the same order),
  ka.sort();
  kb.sort();
  //~~~cheap key test
  for (i = ka.length - 1; i >= 0; i--) {
    if (ka[i] != kb[i])
      return false;
  }
  //equivalent values for every corresponding key, and
  //~~~possibly expensive deep test
  for (i = ka.length - 1; i >= 0; i--) {
    key = ka[i];
    if (!_deepEqual(a[key], b[key])) return false;
  }
  return true;
}

// 8. The non-equivalence assertion tests for any deep inequality.
// assert.notDeepEqual(actual, expected, message_opt);

assert.notDeepEqual = function notDeepEqual(actual, expected, message) {
  if (_deepEqual(actual, expected)) {
    fail(actual, expected, message, 'notDeepEqual', assert.notDeepEqual);
  }
};

// 9. The strict equality assertion tests strict equality, as determined by ===.
// assert.strictEqual(actual, expected, message_opt);

assert.strictEqual = function strictEqual(actual, expected, message) {
  if (actual !== expected) {
    fail(actual, expected, message, '===', assert.strictEqual);
  }
};

// 10. The strict non-equality assertion tests for strict inequality, as
// determined by !==.  assert.notStrictEqual(actual, expected, message_opt);

assert.notStrictEqual = function notStrictEqual(actual, expected, message) {
  if (actual === expected) {
    fail(actual, expected, message, '!==', assert.notStrictEqual);
  }
};

function expectedException(actual, expected) {
  if (!actual || !expected) {
    return false;
  }

  if (Object.prototype.toString.call(expected) == '[object RegExp]') {
    return expected.test(actual);
  } else if (actual instanceof expected) {
    return true;
  } else if (expected.call({}, actual) === true) {
    return true;
  }

  return false;
}

function _throws(shouldThrow, block, expected, message) {
  var actual;

  if (util.isString(expected)) {
    message = expected;
    expected = null;
  }

  try {
    block();
  } catch (e) {
    actual = e;
  }

  message = (expected && expected.name ? ' (' + expected.name + ').' : '.') +
            (message ? ' ' + message : '.');

  if (shouldThrow && !actual) {
    fail(actual, expected, 'Missing expected exception' + message);
  }

  if (!shouldThrow && expectedException(actual, expected)) {
    fail(actual, expected, 'Got unwanted exception' + message);
  }

  if ((shouldThrow && actual && expected &&
      !expectedException(actual, expected)) || (!shouldThrow && actual)) {
    throw actual;
  }
}

// 11. Expected to throw an error:
// assert.throws(block, Error_opt, message_opt);

assert.throws = function(block, /*optional*/error, /*optional*/message) {
  _throws.apply(this, [true].concat(pSlice.call(arguments)));
};

// EXTENSION! This is annoying to write outside this module.
assert.doesNotThrow = function(block, /*optional*/message) {
  _throws.apply(this, [false].concat(pSlice.call(arguments)));
};

assert.ifError = function(err) { if (err) {throw err;}};

return assert;
});
