Adding src/third_party/chaijs (Javascript assertion library).

third_party/chaijs/chai.js

+(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.chai = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+module.exports = require('./lib/chai');
+
+},{"./lib/chai":2}],2:[function(require,module,exports){
+/*!
+ * chai
+ * Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+var used = []
+  , exports = module.exports = {};
+
+/*!
+ * Chai version
+ */
+
+exports.version = '3.4.1';
+
+/*!
+ * Assertion Error
+ */
+
+exports.AssertionError = require('assertion-error');
+
+/*!
+ * Utils for plugins (not exported)
+ */
+
+var util = require('./chai/utils');
+
+/**
+ * # .use(function)
+ *
+ * Provides a way to extend the internals of Chai
+ *
+ * @param {Function}
+ * @returns {this} for chaining
+ * @api public
+ */
+
+exports.use = function (fn) {
+  if (!~used.indexOf(fn)) {
+    fn(this, util);
+    used.push(fn);
+  }
+
+  return this;
+};
+
+/*!
+ * Utility Functions
+ */
+
+exports.util = util;
+
+/*!
+ * Configuration
+ */
+
+var config = require('./chai/config');
+exports.config = config;
+
+/*!
+ * Primary `Assertion` prototype
+ */
+
+var assertion = require('./chai/assertion');
+exports.use(assertion);
+
+/*!
+ * Core Assertions
+ */
+
+var core = require('./chai/core/assertions');
+exports.use(core);
+
+/*!
+ * Expect interface
+ */
+
+var expect = require('./chai/interface/expect');
+exports.use(expect);
+
+/*!
+ * Should interface
+ */
+
+var should = require('./chai/interface/should');
+exports.use(should);
+
+/*!
+ * Assert interface
+ */
+
+var assert = require('./chai/interface/assert');
+exports.use(assert);
+
+},{"./chai/assertion":3,"./chai/config":4,"./chai/core/assertions":5,"./chai/interface/assert":6,"./chai/interface/expect":7,"./chai/interface/should":8,"./chai/utils":22,"assertion-error":30}],3:[function(require,module,exports){
+/*!
+ * chai
+ * http://chaijs.com
+ * Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+var config = require('./config');
+
+module.exports = function (_chai, util) {
+  /*!
+   * Module dependencies.
+   */
+
+  var AssertionError = _chai.AssertionError
+    , flag = util.flag;
+
+  /*!
+   * Module export.
+   */
+
+  _chai.Assertion = Assertion;
+
+  /*!
+   * Assertion Constructor
+   *
+   * Creates object for chaining.
+   *
+   * @api private
+   */
+
+  function Assertion (obj, msg, stack) {
+    flag(this, 'ssfi', stack || arguments.callee);
+    flag(this, 'object', obj);
+    flag(this, 'message', msg);
+  }
+
+  Object.defineProperty(Assertion, 'includeStack', {
+    get: function() {
+      console.warn('Assertion.includeStack is deprecated, use chai.config.includeStack instead.');
+      return config.includeStack;
+    },
+    set: function(value) {
+      console.warn('Assertion.includeStack is deprecated, use chai.config.includeStack instead.');
+      config.includeStack = value;
+    }
+  });
+
+  Object.defineProperty(Assertion, 'showDiff', {
+    get: function() {
+      console.warn('Assertion.showDiff is deprecated, use chai.config.showDiff instead.');
+      return config.showDiff;
+    },
+    set: function(value) {
+      console.warn('Assertion.showDiff is deprecated, use chai.config.showDiff instead.');
+      config.showDiff = value;
+    }
+  });
+
+  Assertion.addProperty = function (name, fn) {
+    util.addProperty(this.prototype, name, fn);
+  };
+
+  Assertion.addMethod = function (name, fn) {
+    util.addMethod(this.prototype, name, fn);
+  };
+
+  Assertion.addChainableMethod = function (name, fn, chainingBehavior) {
+    util.addChainableMethod(this.prototype, name, fn, chainingBehavior);
+  };
+
+  Assertion.overwriteProperty = function (name, fn) {
+    util.overwriteProperty(this.prototype, name, fn);
+  };
+
+  Assertion.overwriteMethod = function (name, fn) {
+    util.overwriteMethod(this.prototype, name, fn);
+  };
+
+  Assertion.overwriteChainableMethod = function (name, fn, chainingBehavior) {
+    util.overwriteChainableMethod(this.prototype, name, fn, chainingBehavior);
+  };
+
+  /**
+   * ### .assert(expression, message, negateMessage, expected, actual, showDiff)
+   *
+   * Executes an expression and check expectations. Throws AssertionError for reporting if test doesn't pass.
+   *
+   * @name assert
+   * @param {Philosophical} expression to be tested
+   * @param {String|Function} message or function that returns message to display if expression fails
+   * @param {String|Function} negatedMessage or function that returns negatedMessage to display if negated expression fails
+   * @param {Mixed} expected value (remember to check for negation)
+   * @param {Mixed} actual (optional) will default to `this.obj`
+   * @param {Boolean} showDiff (optional) when set to `true`, assert will display a diff in addition to the message if expression fails
+   * @api private
+   */
+
+  Assertion.prototype.assert = function (expr, msg, negateMsg, expected, _actual, showDiff) {
+    var ok = util.test(this, arguments);
+    if (true !== showDiff) showDiff = false;
+    if (true !== config.showDiff) showDiff = false;
+
+    if (!ok) {
+      var msg = util.getMessage(this, arguments)
+        , actual = util.getActual(this, arguments);
+      throw new AssertionError(msg, {
+          actual: actual
+        , expected: expected
+        , showDiff: showDiff
+      }, (config.includeStack) ? this.assert : flag(this, 'ssfi'));
+    }
+  };
+
+  /*!
+   * ### ._obj
+   *
+   * Quick reference to stored `actual` value for plugin developers.
+   *
+   * @api private
+   */
+
+  Object.defineProperty(Assertion.prototype, '_obj',
+    { get: function () {
+        return flag(this, 'object');
+      }
+    , set: function (val) {
+        flag(this, 'object', val);
+      }
+  });
+};
+
+},{"./config":4}],4:[function(require,module,exports){
+module.exports = {
+
+  /**
+   * ### config.includeStack
+   *
+   * User configurable property, influences whether stack trace
+   * is included in Assertion error message. Default of false
+   * suppresses stack trace in the error message.
+   *
+   *     chai.config.includeStack = true;  // enable stack on error
+   *
+   * @param {Boolean}
+   * @api public
+   */
+
+   includeStack: false,
+
+  /**
+   * ### config.showDiff
+   *
+   * User configurable property, influences whether or not
+   * the `showDiff` flag should be included in the thrown
+   * AssertionErrors. `false` will always be `false`; `true`
+   * will be true when the assertion has requested a diff
+   * be shown.
+   *
+   * @param {Boolean}
+   * @api public
+   */
+
+  showDiff: true,
+
+  /**
+   * ### config.truncateThreshold
+   *
+   * User configurable property, sets length threshold for actual and
+   * expected values in assertion errors. If this threshold is exceeded, for
+   * example for large data structures, the value is replaced with something
+   * like `[ Array(3) ]` or `{ Object (prop1, prop2) }`.
+   *
+   * Set it to zero if you want to disable truncating altogether.
+   *
+   * This is especially userful when doing assertions on arrays: having this
+   * set to a reasonable large value makes the failure messages readily
+   * inspectable.
+   *
+   *     chai.config.truncateThreshold = 0;  // disable truncating
+   *
+   * @param {Number}
+   * @api public
+   */
+
+  truncateThreshold: 40
+
+};
+
+},{}],5:[function(require,module,exports){
+/*!
+ * chai
+ * http://chaijs.com
+ * Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+module.exports = function (chai, _) {
+  var Assertion = chai.Assertion
+    , toString = Object.prototype.toString
+    , flag = _.flag;
+
+  /**
+   * ### Language Chains
+   *
+   * The following are provided as chainable getters to
+   * improve the readability of your assertions. They
+   * do not provide testing capabilities unless they
+   * have been overwritten by a plugin.
+   *
+   * **Chains**
+   *
+   * - to
+   * - be
+   * - been
+   * - is
+   * - that
+   * - which
+   * - and
+   * - has
+   * - have
+   * - with
+   * - at
+   * - of
+   * - same
+   *
+   * @name language chains
+   * @api public
+   */
+
+  [ 'to', 'be', 'been'
+  , 'is', 'and', 'has', 'have'
+  , 'with', 'that', 'which', 'at'
+  , 'of', 'same' ].forEach(function (chain) {
+    Assertion.addProperty(chain, function () {
+      return this;
+    });
+  });
+
+  /**
+   * ### .not
+   *
+   * Negates any of assertions following in the chain.
+   *
+   *     expect(foo).to.not.equal('bar');
+   *     expect(goodFn).to.not.throw(Error);
+   *     expect({ foo: 'baz' }).to.have.property('foo')
+   *       .and.not.equal('bar');
+   *
+   * @name not
+   * @api public
+   */
+
+  Assertion.addProperty('not', function () {
+    flag(this, 'negate', true);
+  });
+
+  /**
+   * ### .deep
+   *
+   * Sets the `deep` flag, later used by the `equal` and
+   * `property` assertions.
+   *
+   *     expect(foo).to.deep.equal({ bar: 'baz' });
+   *     expect({ foo: { bar: { baz: 'quux' } } })
+   *       .to.have.deep.property('foo.bar.baz', 'quux');
+   *
+   * `.deep.property` special characters can be escaped
+   * by adding two slashes before the `.` or `[]`.
+   *
+   *     var deepCss = { '.link': { '[target]': 42 }};
+   *     expect(deepCss).to.have.deep.property('\\.link.\\[target\\]', 42);
+   *
+   * @name deep
+   * @api public
+   */
+
+  Assertion.addProperty('deep', function () {
+    flag(this, 'deep', true);
+  });
+
+  /**
+   * ### .any
+   *
+   * Sets the `any` flag, (opposite of the `all` flag)
+   * later used in the `keys` assertion.
+   *
+   *     expect(foo).to.have.any.keys('bar', 'baz');
+   *
+   * @name any
+   * @api public
+   */
+
+  Assertion.addProperty('any', function () {
+    flag(this, 'any', true);
+    flag(this, 'all', false)
+  });
+
+
+  /**
+   * ### .all
+   *
+   * Sets the `all` flag (opposite of the `any` flag)
+   * later used by the `keys` assertion.
+   *
+   *     expect(foo).to.have.all.keys('bar', 'baz');
+   *
+   * @name all
+   * @api public
+   */
+
+  Assertion.addProperty('all', function () {
+    flag(this, 'all', true);
+    flag(this, 'any', false);
+  });
+
+  /**
+   * ### .a(type)
+   *
+   * The `a` and `an` assertions are aliases that can be
+   * used either as language chains or to assert a value's
+   * type.
+   *
+   *     // typeof
+   *     expect('test').to.be.a('string');
+   *     expect({ foo: 'bar' }).to.be.an('object');
+   *     expect(null).to.be.a('null');
+   *     expect(undefined).to.be.an('undefined');
+   *     expect(new Error).to.be.an('error');
+   *     expect(new Promise).to.be.a('promise');
+   *     expect(new Float32Array()).to.be.a('float32array');
+   *     expect(Symbol()).to.be.a('symbol');
+   *
+   *     // es6 overrides
+   *     expect({[Symbol.toStringTag]:()=>'foo'}).to.be.a('foo');
+   *
+   *     // language chain
+   *     expect(foo).to.be.an.instanceof(Foo);
+   *
+   * @name a
+   * @alias an
+   * @param {String} type
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function an (type, msg) {
+    if (msg) flag(this, 'message', msg);
+    type = type.toLowerCase();
+    var obj = flag(this, 'object')
+      , article = ~[ 'a', 'e', 'i', 'o', 'u' ].indexOf(type.charAt(0)) ? 'an ' : 'a ';
+
+    this.assert(
+        type === _.type(obj)
+      , 'expected #{this} to be ' + article + type
+      , 'expected #{this} not to be ' + article + type
+    );
+  }
+
+  Assertion.addChainableMethod('an', an);
+  Assertion.addChainableMethod('a', an);
+
+  /**
+   * ### .include(value)
+   *
+   * The `include` and `contain` assertions can be used as either property
+   * based language chains or as methods to assert the inclusion of an object
+   * in an array or a substring in a string. When used as language chains,
+   * they toggle the `contains` flag for the `keys` assertion.
+   *
+   *     expect([1,2,3]).to.include(2);
+   *     expect('foobar').to.contain('foo');
+   *     expect({ foo: 'bar', hello: 'universe' }).to.include.keys('foo');
+   *
+   * @name include
+   * @alias contain
+   * @alias includes
+   * @alias contains
+   * @param {Object|String|Number} obj
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function includeChainingBehavior () {
+    flag(this, 'contains', true);
+  }
+
+  function include (val, msg) {
+    _.expectTypes(this, ['array', 'object', 'string']);
+
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    var expected = false;
+
+    if (_.type(obj) === 'array' && _.type(val) === 'object') {
+      for (var i in obj) {
+        if (_.eql(obj[i], val)) {
+          expected = true;
+          break;
+        }
+      }
+    } else if (_.type(val) === 'object') {
+      if (!flag(this, 'negate')) {
+        for (var k in val) new Assertion(obj).property(k, val[k]);
+        return;
+      }
+      var subset = {};
+      for (var k in val) subset[k] = obj[k];
+      expected = _.eql(subset, val);
+    } else {
+      expected = (obj != undefined) && ~obj.indexOf(val);
+    }
+    this.assert(
+        expected
+      , 'expected #{this} to include ' + _.inspect(val)
+      , 'expected #{this} to not include ' + _.inspect(val));
+  }
+
+  Assertion.addChainableMethod('include', include, includeChainingBehavior);
+  Assertion.addChainableMethod('contain', include, includeChainingBehavior);
+  Assertion.addChainableMethod('contains', include, includeChainingBehavior);
+  Assertion.addChainableMethod('includes', include, includeChainingBehavior);
+
+  /**
+   * ### .ok
+   *
+   * Asserts that the target is truthy.
+   *
+   *     expect('everything').to.be.ok;
+   *     expect(1).to.be.ok;
+   *     expect(false).to.not.be.ok;
+   *     expect(undefined).to.not.be.ok;
+   *     expect(null).to.not.be.ok;
+   *
+   * @name ok
+   * @api public
+   */
+
+  Assertion.addProperty('ok', function () {
+    this.assert(
+        flag(this, 'object')
+      , 'expected #{this} to be truthy'
+      , 'expected #{this} to be falsy');
+  });
+
+  /**
+   * ### .true
+   *
+   * Asserts that the target is `true`.
+   *
+   *     expect(true).to.be.true;
+   *     expect(1).to.not.be.true;
+   *
+   * @name true
+   * @api public
+   */
+
+  Assertion.addProperty('true', function () {
+    this.assert(
+        true === flag(this, 'object')
+      , 'expected #{this} to be true'
+      , 'expected #{this} to be false'
+      , this.negate ? false : true
+    );
+  });
+
+  /**
+   * ### .false
+   *
+   * Asserts that the target is `false`.
+   *
+   *     expect(false).to.be.false;
+   *     expect(0).to.not.be.false;
+   *
+   * @name false
+   * @api public
+   */
+
+  Assertion.addProperty('false', function () {
+    this.assert(
+        false === flag(this, 'object')
+      , 'expected #{this} to be false'
+      , 'expected #{this} to be true'
+      , this.negate ? true : false
+    );
+  });
+
+  /**
+   * ### .null
+   *
+   * Asserts that the target is `null`.
+   *
+   *     expect(null).to.be.null;
+   *     expect(undefined).to.not.be.null;
+   *
+   * @name null
+   * @api public
+   */
+
+  Assertion.addProperty('null', function () {
+    this.assert(
+        null === flag(this, 'object')
+      , 'expected #{this} to be null'
+      , 'expected #{this} not to be null'
+    );
+  });
+
+  /**
+   * ### .undefined
+   *
+   * Asserts that the target is `undefined`.
+   *
+   *     expect(undefined).to.be.undefined;
+   *     expect(null).to.not.be.undefined;
+   *
+   * @name undefined
+   * @api public
+   */
+
+  Assertion.addProperty('undefined', function () {
+    this.assert(
+        undefined === flag(this, 'object')
+      , 'expected #{this} to be undefined'
+      , 'expected #{this} not to be undefined'
+    );
+  });
+
+  /**
+   * ### .NaN
+   * Asserts that the target is `NaN`.
+   *
+   *     expect('foo').to.be.NaN;
+   *     expect(4).not.to.be.NaN;
+   *
+   * @name NaN
+   * @api public
+   */
+
+  Assertion.addProperty('NaN', function () {
+    this.assert(
+        isNaN(flag(this, 'object'))
+        , 'expected #{this} to be NaN'
+        , 'expected #{this} not to be NaN'
+    );
+  });
+
+  /**
+   * ### .exist
+   *
+   * Asserts that the target is neither `null` nor `undefined`.
+   *
+   *     var foo = 'hi'
+   *       , bar = null
+   *       , baz;
+   *
+   *     expect(foo).to.exist;
+   *     expect(bar).to.not.exist;
+   *     expect(baz).to.not.exist;
+   *
+   * @name exist
+   * @api public
+   */
+
+  Assertion.addProperty('exist', function () {
+    this.assert(
+        null != flag(this, 'object')
+      , 'expected #{this} to exist'
+      , 'expected #{this} to not exist'
+    );
+  });
+
+
+  /**
+   * ### .empty
+   *
+   * Asserts that the target's length is `0`. For arrays and strings, it checks
+   * the `length` property. For objects, it gets the count of
+   * enumerable keys.
+   *
+   *     expect([]).to.be.empty;
+   *     expect('').to.be.empty;
+   *     expect({}).to.be.empty;
+   *
+   * @name empty
+   * @api public
+   */
+
+  Assertion.addProperty('empty', function () {
+    var obj = flag(this, 'object')
+      , expected = obj;
+
+    if (Array.isArray(obj) || 'string' === typeof object) {
+      expected = obj.length;
+    } else if (typeof obj === 'object') {
+      expected = Object.keys(obj).length;
+    }
+
+    this.assert(
+        !expected
+      , 'expected #{this} to be empty'
+      , 'expected #{this} not to be empty'
+    );
+  });
+
+  /**
+   * ### .arguments
+   *
+   * Asserts that the target is an arguments object.
+   *
+   *     function test () {
+   *       expect(arguments).to.be.arguments;
+   *     }
+   *
+   * @name arguments
+   * @alias Arguments
+   * @api public
+   */
+
+  function checkArguments () {
+    var obj = flag(this, 'object')
+      , type = Object.prototype.toString.call(obj);
+    this.assert(
+        '[object Arguments]' === type
+      , 'expected #{this} to be arguments but got ' + type
+      , 'expected #{this} to not be arguments'
+    );
+  }
+
+  Assertion.addProperty('arguments', checkArguments);
+  Assertion.addProperty('Arguments', checkArguments);
+
+  /**
+   * ### .equal(value)
+   *
+   * Asserts that the target is strictly equal (`===`) to `value`.
+   * Alternately, if the `deep` flag is set, asserts that
+   * the target is deeply equal to `value`.
+   *
+   *     expect('hello').to.equal('hello');
+   *     expect(42).to.equal(42);
+   *     expect(1).to.not.equal(true);
+   *     expect({ foo: 'bar' }).to.not.equal({ foo: 'bar' });
+   *     expect({ foo: 'bar' }).to.deep.equal({ foo: 'bar' });
+   *
+   * @name equal
+   * @alias equals
+   * @alias eq
+   * @alias deep.equal
+   * @param {Mixed} value
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertEqual (val, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    if (flag(this, 'deep')) {
+      return this.eql(val);
+    } else {
+      this.assert(
+          val === obj
+        , 'expected #{this} to equal #{exp}'
+        , 'expected #{this} to not equal #{exp}'
+        , val
+        , this._obj
+        , true
+      );
+    }
+  }
+
+  Assertion.addMethod('equal', assertEqual);
+  Assertion.addMethod('equals', assertEqual);
+  Assertion.addMethod('eq', assertEqual);
+
+  /**
+   * ### .eql(value)
+   *
+   * Asserts that the target is deeply equal to `value`.
+   *
+   *     expect({ foo: 'bar' }).to.eql({ foo: 'bar' });
+   *     expect([ 1, 2, 3 ]).to.eql([ 1, 2, 3 ]);
+   *
+   * @name eql
+   * @alias eqls
+   * @param {Mixed} value
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertEql(obj, msg) {
+    if (msg) flag(this, 'message', msg);
+    this.assert(
+        _.eql(obj, flag(this, 'object'))
+      , 'expected #{this} to deeply equal #{exp}'
+      , 'expected #{this} to not deeply equal #{exp}'
+      , obj
+      , this._obj
+      , true
+    );
+  }
+
+  Assertion.addMethod('eql', assertEql);
+  Assertion.addMethod('eqls', assertEql);
+
+  /**
+   * ### .above(value)
+   *
+   * Asserts that the target is greater than `value`.
+   *
+   *     expect(10).to.be.above(5);
+   *
+   * Can also be used in conjunction with `length` to
+   * assert a minimum length. The benefit being a
+   * more informative error message than if the length
+   * was supplied directly.
+   *
+   *     expect('foo').to.have.length.above(2);
+   *     expect([ 1, 2, 3 ]).to.have.length.above(2);
+   *
+   * @name above
+   * @alias gt
+   * @alias greaterThan
+   * @param {Number} value
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertAbove (n, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    if (flag(this, 'doLength')) {
+      new Assertion(obj, msg).to.have.property('length');
+      var len = obj.length;
+      this.assert(
+          len > n
+        , 'expected #{this} to have a length above #{exp} but got #{act}'
+        , 'expected #{this} to not have a length above #{exp}'
+        , n
+        , len
+      );
+    } else {
+      this.assert(
+          obj > n
+        , 'expected #{this} to be above ' + n
+        , 'expected #{this} to be at most ' + n
+      );
+    }
+  }
+
+  Assertion.addMethod('above', assertAbove);
+  Assertion.addMethod('gt', assertAbove);
+  Assertion.addMethod('greaterThan', assertAbove);
+
+  /**
+   * ### .least(value)
+   *
+   * Asserts that the target is greater than or equal to `value`.
+   *
+   *     expect(10).to.be.at.least(10);
+   *
+   * Can also be used in conjunction with `length` to
+   * assert a minimum length. The benefit being a
+   * more informative error message than if the length
+   * was supplied directly.
+   *
+   *     expect('foo').to.have.length.of.at.least(2);
+   *     expect([ 1, 2, 3 ]).to.have.length.of.at.least(3);
+   *
+   * @name least
+   * @alias gte
+   * @param {Number} value
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertLeast (n, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    if (flag(this, 'doLength')) {
+      new Assertion(obj, msg).to.have.property('length');
+      var len = obj.length;
+      this.assert(
+          len >= n
+        , 'expected #{this} to have a length at least #{exp} but got #{act}'
+        , 'expected #{this} to have a length below #{exp}'
+        , n
+        , len
+      );
+    } else {
+      this.assert(
+          obj >= n
+        , 'expected #{this} to be at least ' + n
+        , 'expected #{this} to be below ' + n
+      );
+    }
+  }
+
+  Assertion.addMethod('least', assertLeast);
+  Assertion.addMethod('gte', assertLeast);
+
+  /**
+   * ### .below(value)
+   *
+   * Asserts that the target is less than `value`.
+   *
+   *     expect(5).to.be.below(10);
+   *
+   * Can also be used in conjunction with `length` to
+   * assert a maximum length. The benefit being a
+   * more informative error message than if the length
+   * was supplied directly.
+   *
+   *     expect('foo').to.have.length.below(4);
+   *     expect([ 1, 2, 3 ]).to.have.length.below(4);
+   *
+   * @name below
+   * @alias lt
+   * @alias lessThan
+   * @param {Number} value
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertBelow (n, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    if (flag(this, 'doLength')) {
+      new Assertion(obj, msg).to.have.property('length');
+      var len = obj.length;
+      this.assert(
+          len < n
+        , 'expected #{this} to have a length below #{exp} but got #{act}'
+        , 'expected #{this} to not have a length below #{exp}'
+        , n
+        , len
+      );
+    } else {
+      this.assert(
+          obj < n
+        , 'expected #{this} to be below ' + n
+        , 'expected #{this} to be at least ' + n
+      );
+    }
+  }
+
+  Assertion.addMethod('below', assertBelow);
+  Assertion.addMethod('lt', assertBelow);
+  Assertion.addMethod('lessThan', assertBelow);
+
+  /**
+   * ### .most(value)
+   *
+   * Asserts that the target is less than or equal to `value`.
+   *
+   *     expect(5).to.be.at.most(5);
+   *
+   * Can also be used in conjunction with `length` to
+   * assert a maximum length. The benefit being a
+   * more informative error message than if the length
+   * was supplied directly.
+   *
+   *     expect('foo').to.have.length.of.at.most(4);
+   *     expect([ 1, 2, 3 ]).to.have.length.of.at.most(3);
+   *
+   * @name most
+   * @alias lte
+   * @param {Number} value
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertMost (n, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    if (flag(this, 'doLength')) {
+      new Assertion(obj, msg).to.have.property('length');
+      var len = obj.length;
+      this.assert(
+          len <= n
+        , 'expected #{this} to have a length at most #{exp} but got #{act}'
+        , 'expected #{this} to have a length above #{exp}'
+        , n
+        , len
+      );
+    } else {
+      this.assert(
+          obj <= n
+        , 'expected #{this} to be at most ' + n
+        , 'expected #{this} to be above ' + n
+      );
+    }
+  }
+
+  Assertion.addMethod('most', assertMost);
+  Assertion.addMethod('lte', assertMost);
+
+  /**
+   * ### .within(start, finish)
+   *
+   * Asserts that the target is within a range.
+   *
+   *     expect(7).to.be.within(5,10);
+   *
+   * Can also be used in conjunction with `length` to
+   * assert a length range. The benefit being a
+   * more informative error message than if the length
+   * was supplied directly.
+   *
+   *     expect('foo').to.have.length.within(2,4);
+   *     expect([ 1, 2, 3 ]).to.have.length.within(2,4);
+   *
+   * @name within
+   * @param {Number} start lowerbound inclusive
+   * @param {Number} finish upperbound inclusive
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  Assertion.addMethod('within', function (start, finish, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object')
+      , range = start + '..' + finish;
+    if (flag(this, 'doLength')) {
+      new Assertion(obj, msg).to.have.property('length');
+      var len = obj.length;
+      this.assert(
+          len >= start && len <= finish
+        , 'expected #{this} to have a length within ' + range
+        , 'expected #{this} to not have a length within ' + range
+      );
+    } else {
+      this.assert(
+          obj >= start && obj <= finish
+        , 'expected #{this} to be within ' + range
+        , 'expected #{this} to not be within ' + range
+      );
+    }
+  });
+
+  /**
+   * ### .instanceof(constructor)
+   *
+   * Asserts that the target is an instance of `constructor`.
+   *
+   *     var Tea = function (name) { this.name = name; }
+   *       , Chai = new Tea('chai');
+   *
+   *     expect(Chai).to.be.an.instanceof(Tea);
+   *     expect([ 1, 2, 3 ]).to.be.instanceof(Array);
+   *
+   * @name instanceof
+   * @param {Constructor} constructor
+   * @param {String} message _optional_
+   * @alias instanceOf
+   * @api public
+   */
+
+  function assertInstanceOf (constructor, msg) {
+    if (msg) flag(this, 'message', msg);
+    var name = _.getName(constructor);
+    this.assert(
+        flag(this, 'object') instanceof constructor
+      , 'expected #{this} to be an instance of ' + name
+      , 'expected #{this} to not be an instance of ' + name
+    );
+  };
+
+  Assertion.addMethod('instanceof', assertInstanceOf);
+  Assertion.addMethod('instanceOf', assertInstanceOf);
+
+  /**
+   * ### .property(name, [value])
+   *
+   * Asserts that the target has a property `name`, optionally asserting that
+   * the value of that property is strictly equal to  `value`.
+   * If the `deep` flag is set, you can use dot- and bracket-notation for deep
+   * references into objects and arrays.
+   *
+   *     // simple referencing
+   *     var obj = { foo: 'bar' };
+   *     expect(obj).to.have.property('foo');
+   *     expect(obj).to.have.property('foo', 'bar');
+   *
+   *     // deep referencing
+   *     var deepObj = {
+   *         green: { tea: 'matcha' }
+   *       , teas: [ 'chai', 'matcha', { tea: 'konacha' } ]
+   *     };
+   *
+   *     expect(deepObj).to.have.deep.property('green.tea', 'matcha');
+   *     expect(deepObj).to.have.deep.property('teas[1]', 'matcha');
+   *     expect(deepObj).to.have.deep.property('teas[2].tea', 'konacha');
+   *
+   * You can also use an array as the starting point of a `deep.property`
+   * assertion, or traverse nested arrays.
+   *
+   *     var arr = [
+   *         [ 'chai', 'matcha', 'konacha' ]
+   *       , [ { tea: 'chai' }
+   *         , { tea: 'matcha' }
+   *         , { tea: 'konacha' } ]
+   *     ];
+   *
+   *     expect(arr).to.have.deep.property('[0][1]', 'matcha');
+   *     expect(arr).to.have.deep.property('[1][2].tea', 'konacha');
+   *
+   * Furthermore, `property` changes the subject of the assertion
+   * to be the value of that property from the original object. This
+   * permits for further chainable assertions on that property.
+   *
+   *     expect(obj).to.have.property('foo')
+   *       .that.is.a('string');
+   *     expect(deepObj).to.have.property('green')
+   *       .that.is.an('object')
+   *       .that.deep.equals({ tea: 'matcha' });
+   *     expect(deepObj).to.have.property('teas')
+   *       .that.is.an('array')
+   *       .with.deep.property('[2]')
+   *         .that.deep.equals({ tea: 'konacha' });
+   *
+   * Note that dots and bracket in `name` must be backslash-escaped when
+   * the `deep` flag is set, while they must NOT be escaped when the `deep`
+   * flag is not set.
+   *
+   *     // simple referencing
+   *     var css = { '.link[target]': 42 };
+   *     expect(css).to.have.property('.link[target]', 42);
+   *
+   *     // deep referencing
+   *     var deepCss = { '.link': { '[target]': 42 }};
+   *     expect(deepCss).to.have.deep.property('\\.link.\\[target\\]', 42);
+   *
+   * @name property
+   * @alias deep.property
+   * @param {String} name
+   * @param {Mixed} value (optional)
+   * @param {String} message _optional_
+   * @returns value of property for chaining
+   * @api public
+   */
+
+  Assertion.addMethod('property', function (name, val, msg) {
+    if (msg) flag(this, 'message', msg);
+
+    var isDeep = !!flag(this, 'deep')
+      , descriptor = isDeep ? 'deep property ' : 'property '
+      , negate = flag(this, 'negate')
+      , obj = flag(this, 'object')
+      , pathInfo = isDeep ? _.getPathInfo(name, obj) : null
+      , hasProperty = isDeep
+        ? pathInfo.exists
+        : _.hasProperty(name, obj)
+      , value = isDeep
+        ? pathInfo.value
+        : obj[name];
+
+    if (negate && arguments.length > 1) {
+      if (undefined === value) {
+        msg = (msg != null) ? msg + ': ' : '';
+        throw new Error(msg + _.inspect(obj) + ' has no ' + descriptor + _.inspect(name));
+      }
+    } else {
+      this.assert(
+          hasProperty
+        , 'expected #{this} to have a ' + descriptor + _.inspect(name)
+        , 'expected #{this} to not have ' + descriptor + _.inspect(name));
+    }
+
+    if (arguments.length > 1) {
+      this.assert(
+          val === value
+        , 'expected #{this} to have a ' + descriptor + _.inspect(name) + ' of #{exp}, but got #{act}'
+        , 'expected #{this} to not have a ' + descriptor + _.inspect(name) + ' of #{act}'
+        , val
+        , value
+      );
+    }
+
+    flag(this, 'object', value);
+  });
+
+
+  /**
+   * ### .ownProperty(name)
+   *
+   * Asserts that the target has an own property `name`.
+   *
+   *     expect('test').to.have.ownProperty('length');
+   *
+   * @name ownProperty
+   * @alias haveOwnProperty
+   * @param {String} name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertOwnProperty (name, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    this.assert(
+        obj.hasOwnProperty(name)
+      , 'expected #{this} to have own property ' + _.inspect(name)
+      , 'expected #{this} to not have own property ' + _.inspect(name)
+    );
+  }
+
+  Assertion.addMethod('ownProperty', assertOwnProperty);
+  Assertion.addMethod('haveOwnProperty', assertOwnProperty);
+
+  /**
+   * ### .ownPropertyDescriptor(name[, descriptor[, message]])
+   *
+   * Asserts that the target has an own property descriptor `name`, that optionally matches `descriptor`.
+   *
+   *     expect('test').to.have.ownPropertyDescriptor('length');
+   *     expect('test').to.have.ownPropertyDescriptor('length', { enumerable: false, configurable: false, writable: false, value: 4 });
+   *     expect('test').not.to.have.ownPropertyDescriptor('length', { enumerable: false, configurable: false, writable: false, value: 3 });
+   *     expect('test').ownPropertyDescriptor('length').to.have.property('enumerable', false);
+   *     expect('test').ownPropertyDescriptor('length').to.have.keys('value');
+   *
+   * @name ownPropertyDescriptor
+   * @alias haveOwnPropertyDescriptor
+   * @param {String} name
+   * @param {Object} descriptor _optional_
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertOwnPropertyDescriptor (name, descriptor, msg) {
+    if (typeof descriptor === 'string') {
+      msg = descriptor;
+      descriptor = null;
+    }
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    var actualDescriptor = Object.getOwnPropertyDescriptor(Object(obj), name);
+    if (actualDescriptor && descriptor) {
+      this.assert(
+          _.eql(descriptor, actualDescriptor)
+        , 'expected the own property descriptor for ' + _.inspect(name) + ' on #{this} to match ' + _.inspect(descriptor) + ', got ' + _.inspect(actualDescriptor)
+        , 'expected the own property descriptor for ' + _.inspect(name) + ' on #{this} to not match ' + _.inspect(descriptor)
+        , descriptor
+        , actualDescriptor
+        , true
+      );
+    } else {
+      this.assert(
+          actualDescriptor
+        , 'expected #{this} to have an own property descriptor for ' + _.inspect(name)
+        , 'expected #{this} to not have an own property descriptor for ' + _.inspect(name)
+      );
+    }
+    flag(this, 'object', actualDescriptor);
+  }
+
+  Assertion.addMethod('ownPropertyDescriptor', assertOwnPropertyDescriptor);
+  Assertion.addMethod('haveOwnPropertyDescriptor', assertOwnPropertyDescriptor);
+
+  /**
+   * ### .length
+   *
+   * Sets the `doLength` flag later used as a chain precursor to a value
+   * comparison for the `length` property.
+   *
+   *     expect('foo').to.have.length.above(2);
+   *     expect([ 1, 2, 3 ]).to.have.length.above(2);
+   *     expect('foo').to.have.length.below(4);
+   *     expect([ 1, 2, 3 ]).to.have.length.below(4);
+   *     expect('foo').to.have.length.within(2,4);
+   *     expect([ 1, 2, 3 ]).to.have.length.within(2,4);
+   *
+   * *Deprecation notice:* Using `length` as an assertion will be deprecated
+   * in version 2.4.0 and removed in 3.0.0. Code using the old style of
+   * asserting for `length` property value using `length(value)` should be
+   * switched to use `lengthOf(value)` instead.
+   *
+   * @name length
+   * @api public
+   */
+
+  /**
+   * ### .lengthOf(value[, message])
+   *
+   * Asserts that the target's `length` property has
+   * the expected value.
+   *
+   *     expect([ 1, 2, 3]).to.have.lengthOf(3);
+   *     expect('foobar').to.have.lengthOf(6);
+   *
+   * @name lengthOf
+   * @param {Number} length
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertLengthChain () {
+    flag(this, 'doLength', true);
+  }
+
+  function assertLength (n, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    new Assertion(obj, msg).to.have.property('length');
+    var len = obj.length;
+
+    this.assert(
+        len == n
+      , 'expected #{this} to have a length of #{exp} but got #{act}'
+      , 'expected #{this} to not have a length of #{act}'
+      , n
+      , len
+    );
+  }
+
+  Assertion.addChainableMethod('length', assertLength, assertLengthChain);
+  Assertion.addMethod('lengthOf', assertLength);
+
+  /**
+   * ### .match(regexp)
+   *
+   * Asserts that the target matches a regular expression.
+   *
+   *     expect('foobar').to.match(/^foo/);
+   *
+   * @name match
+   * @alias matches
+   * @param {RegExp} RegularExpression
+   * @param {String} message _optional_
+   * @api public
+   */
+  function assertMatch(re, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    this.assert(
+        re.exec(obj)
+      , 'expected #{this} to match ' + re
+      , 'expected #{this} not to match ' + re
+    );
+  }
+
+  Assertion.addMethod('match', assertMatch);
+  Assertion.addMethod('matches', assertMatch);
+
+  /**
+   * ### .string(string)
+   *
+   * Asserts that the string target contains another string.
+   *
+   *     expect('foobar').to.have.string('bar');
+   *
+   * @name string
+   * @param {String} string
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  Assertion.addMethod('string', function (str, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    new Assertion(obj, msg).is.a('string');
+
+    this.assert(
+        ~obj.indexOf(str)
+      , 'expected #{this} to contain ' + _.inspect(str)
+      , 'expected #{this} to not contain ' + _.inspect(str)
+    );
+  });
+
+
+  /**
+   * ### .keys(key1, [key2], [...])
+   *
+   * Asserts that the target contains any or all of the passed-in keys.
+   * Use in combination with `any`, `all`, `contains`, or `have` will affect
+   * what will pass.
+   *
+   * When used in conjunction with `any`, at least one key that is passed
+   * in must exist in the target object. This is regardless whether or not
+   * the `have` or `contain` qualifiers are used. Note, either `any` or `all`
+   * should be used in the assertion. If neither are used, the assertion is
+   * defaulted to `all`.
+   *
+   * When both `all` and `contain` are used, the target object must have at
+   * least all of the passed-in keys but may have more keys not listed.
+   *
+   * When both `all` and `have` are used, the target object must both contain
+   * all of the passed-in keys AND the number of keys in the target object must
+   * match the number of keys passed in (in other words, a target object must
+   * have all and only all of the passed-in keys).
+   *
+   *     expect({ foo: 1, bar: 2 }).to.have.any.keys('foo', 'baz');
+   *     expect({ foo: 1, bar: 2 }).to.have.any.keys('foo');
+   *     expect({ foo: 1, bar: 2 }).to.contain.any.keys('bar', 'baz');
+   *     expect({ foo: 1, bar: 2 }).to.contain.any.keys(['foo']);
+   *     expect({ foo: 1, bar: 2 }).to.contain.any.keys({'foo': 6});
+   *     expect({ foo: 1, bar: 2 }).to.have.all.keys(['bar', 'foo']);
+   *     expect({ foo: 1, bar: 2 }).to.have.all.keys({'bar': 6, 'foo': 7});
+   *     expect({ foo: 1, bar: 2, baz: 3 }).to.contain.all.keys(['bar', 'foo']);
+   *     expect({ foo: 1, bar: 2, baz: 3 }).to.contain.all.keys({'bar': 6});
+   *
+   *
+   * @name keys
+   * @alias key
+   * @param {...String|Array|Object} keys
+   * @api public
+   */
+
+  function assertKeys (keys) {
+    var obj = flag(this, 'object')
+      , str
+      , ok = true
+      , mixedArgsMsg = 'keys must be given single argument of Array|Object|String, or multiple String arguments';
+
+    switch (_.type(keys)) {
+      case "array":
+        if (arguments.length > 1) throw (new Error(mixedArgsMsg));
+        break;
+      case "object":
+        if (arguments.length > 1) throw (new Error(mixedArgsMsg));
+        keys = Object.keys(keys);
+        break;
+      default:
+        keys = Array.prototype.slice.call(arguments);
+    }
+
+    if (!keys.length) throw new Error('keys required');
+
+    var actual = Object.keys(obj)
+      , expected = keys
+      , len = keys.length
+      , any = flag(this, 'any')
+      , all = flag(this, 'all');
+
+    if (!any && !all) {
+      all = true;
+    }
+
+    // Has any
+    if (any) {
+      var intersection = expected.filter(function(key) {
+        return ~actual.indexOf(key);
+      });
+      ok = intersection.length > 0;
+    }
+
+    // Has all
+    if (all) {
+      ok = keys.every(function(key){
+        return ~actual.indexOf(key);
+      });
+      if (!flag(this, 'negate') && !flag(this, 'contains')) {
+        ok = ok && keys.length == actual.length;
+      }
+    }
+
+    // Key string
+    if (len > 1) {
+      keys = keys.map(function(key){
+        return _.inspect(key);
+      });
+      var last = keys.pop();
+      if (all) {
+        str = keys.join(', ') + ', and ' + last;
+      }
+      if (any) {
+        str = keys.join(', ') + ', or ' + last;
+      }
+    } else {
+      str = _.inspect(keys[0]);
+    }
+
+    // Form
+    str = (len > 1 ? 'keys ' : 'key ') + str;
+
+    // Have / include
+    str = (flag(this, 'contains') ? 'contain ' : 'have ') + str;
+
+    // Assertion
+    this.assert(
+        ok
+      , 'expected #{this} to ' + str
+      , 'expected #{this} to not ' + str
+      , expected.slice(0).sort()
+      , actual.sort()
+      , true
+    );
+  }
+
+  Assertion.addMethod('keys', assertKeys);
+  Assertion.addMethod('key', assertKeys);
+
+  /**
+   * ### .throw(constructor)
+   *
+   * Asserts that the function target will throw a specific error, or specific type of error
+   * (as determined using `instanceof`), optionally with a RegExp or string inclusion test
+   * for the error's message.
+   *
+   *     var err = new ReferenceError('This is a bad function.');
+   *     var fn = function () { throw err; }
+   *     expect(fn).to.throw(ReferenceError);
+   *     expect(fn).to.throw(Error);
+   *     expect(fn).to.throw(/bad function/);
+   *     expect(fn).to.not.throw('good function');
+   *     expect(fn).to.throw(ReferenceError, /bad function/);
+   *     expect(fn).to.throw(err);
+   *
+   * Please note that when a throw expectation is negated, it will check each
+   * parameter independently, starting with error constructor type. The appropriate way
+   * to check for the existence of a type of error but for a message that does not match
+   * is to use `and`.
+   *
+   *     expect(fn).to.throw(ReferenceError)
+   *        .and.not.throw(/good function/);
+   *
+   * @name throw
+   * @alias throws
+   * @alias Throw
+   * @param {ErrorConstructor} constructor
+   * @param {String|RegExp} expected error message
+   * @param {String} message _optional_
+   * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
+   * @returns error for chaining (null if no error)
+   * @api public
+   */
+
+  function assertThrows (constructor, errMsg, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    new Assertion(obj, msg).is.a('function');
+
+    var thrown = false
+      , desiredError = null
+      , name = null
+      , thrownError = null;
+
+    if (arguments.length === 0) {
+      errMsg = null;
+      constructor = null;
+    } else if (constructor && (constructor instanceof RegExp || 'string' === typeof constructor)) {
+      errMsg = constructor;
+      constructor = null;
+    } else if (constructor && constructor instanceof Error) {
+      desiredError = constructor;
+      constructor = null;
+      errMsg = null;
+    } else if (typeof constructor === 'function') {
+      name = constructor.prototype.name;
+      if (!name || (name === 'Error' && constructor !== Error)) {
+        name = constructor.name || (new constructor()).name;
+      }
+    } else {
+      constructor = null;
+    }
+
+    try {
+      obj();
+    } catch (err) {
+      // first, check desired error
+      if (desiredError) {
+        this.assert(
+            err === desiredError
+          , 'expected #{this} to throw #{exp} but #{act} was thrown'
+          , 'expected #{this} to not throw #{exp}'
+          , (desiredError instanceof Error ? desiredError.toString() : desiredError)
+          , (err instanceof Error ? err.toString() : err)
+        );
+
+        flag(this, 'object', err);
+        return this;
+      }
+
+      // next, check constructor
+      if (constructor) {
+        this.assert(
+            err instanceof constructor
+          , 'expected #{this} to throw #{exp} but #{act} was thrown'
+          , 'expected #{this} to not throw #{exp} but #{act} was thrown'
+          , name
+          , (err instanceof Error ? err.toString() : err)
+        );
+
+        if (!errMsg) {
+          flag(this, 'object', err);
+          return this;
+        }
+      }
+
+      // next, check message
+      var message = 'error' === _.type(err) && "message" in err
+        ? err.message
+        : '' + err;
+
+      if ((message != null) && errMsg && errMsg instanceof RegExp) {
+        this.assert(
+            errMsg.exec(message)
+          , 'expected #{this} to throw error matching #{exp} but got #{act}'
+          , 'expected #{this} to throw error not matching #{exp}'
+          , errMsg
+          , message
+        );
+
+        flag(this, 'object', err);
+        return this;
+      } else if ((message != null) && errMsg && 'string' === typeof errMsg) {
+        this.assert(
+            ~message.indexOf(errMsg)
+          , 'expected #{this} to throw error including #{exp} but got #{act}'
+          , 'expected #{this} to throw error not including #{act}'
+          , errMsg
+          , message
+        );
+
+        flag(this, 'object', err);
+        return this;
+      } else {
+        thrown = true;
+        thrownError = err;
+      }
+    }
+
+    var actuallyGot = ''
+      , expectedThrown = name !== null
+        ? name
+        : desiredError
+          ? '#{exp}' //_.inspect(desiredError)
+          : 'an error';
+
+    if (thrown) {
+      actuallyGot = ' but #{act} was thrown'
+    }
+
+    this.assert(
+        thrown === true
+      , 'expected #{this} to throw ' + expectedThrown + actuallyGot
+      , 'expected #{this} to not throw ' + expectedThrown + actuallyGot
+      , (desiredError instanceof Error ? desiredError.toString() : desiredError)
+      , (thrownError instanceof Error ? thrownError.toString() : thrownError)
+    );
+
+    flag(this, 'object', thrownError);
+  };
+
+  Assertion.addMethod('throw', assertThrows);
+  Assertion.addMethod('throws', assertThrows);
+  Assertion.addMethod('Throw', assertThrows);
+
+  /**
+   * ### .respondTo(method)
+   *
+   * Asserts that the object or class target will respond to a method.
+   *
+   *     Klass.prototype.bar = function(){};
+   *     expect(Klass).to.respondTo('bar');
+   *     expect(obj).to.respondTo('bar');
+   *
+   * To check if a constructor will respond to a static function,
+   * set the `itself` flag.
+   *
+   *     Klass.baz = function(){};
+   *     expect(Klass).itself.to.respondTo('baz');
+   *
+   * @name respondTo
+   * @alias respondsTo
+   * @param {String} method
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function respondTo (method, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object')
+      , itself = flag(this, 'itself')
+      , context = ('function' === _.type(obj) && !itself)
+        ? obj.prototype[method]
+        : obj[method];
+
+    this.assert(
+        'function' === typeof context
+      , 'expected #{this} to respond to ' + _.inspect(method)
+      , 'expected #{this} to not respond to ' + _.inspect(method)
+    );
+  }
+
+  Assertion.addMethod('respondTo', respondTo);
+  Assertion.addMethod('respondsTo', respondTo);
+
+  /**
+   * ### .itself
+   *
+   * Sets the `itself` flag, later used by the `respondTo` assertion.
+   *
+   *     function Foo() {}
+   *     Foo.bar = function() {}
+   *     Foo.prototype.baz = function() {}
+   *
+   *     expect(Foo).itself.to.respondTo('bar');
+   *     expect(Foo).itself.not.to.respondTo('baz');
+   *
+   * @name itself
+   * @api public
+   */
+
+  Assertion.addProperty('itself', function () {
+    flag(this, 'itself', true);
+  });
+
+  /**
+   * ### .satisfy(method)
+   *
+   * Asserts that the target passes a given truth test.
+   *
+   *     expect(1).to.satisfy(function(num) { return num > 0; });
+   *
+   * @name satisfy
+   * @alias satisfies
+   * @param {Function} matcher
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function satisfy (matcher, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+    var result = matcher(obj);
+    this.assert(
+        result
+      , 'expected #{this} to satisfy ' + _.objDisplay(matcher)
+      , 'expected #{this} to not satisfy' + _.objDisplay(matcher)
+      , this.negate ? false : true
+      , result
+    );
+  }
+
+  Assertion.addMethod('satisfy', satisfy);
+  Assertion.addMethod('satisfies', satisfy);
+
+  /**
+   * ### .closeTo(expected, delta)
+   *
+   * Asserts that the target is equal `expected`, to within a +/- `delta` range.
+   *
+   *     expect(1.5).to.be.closeTo(1, 0.5);
+   *
+   * @name closeTo
+   * @alias approximately
+   * @param {Number} expected
+   * @param {Number} delta
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function closeTo(expected, delta, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+
+    new Assertion(obj, msg).is.a('number');
+    if (_.type(expected) !== 'number' || _.type(delta) !== 'number') {
+      throw new Error('the arguments to closeTo or approximately must be numbers');
+    }
+
+    this.assert(
+        Math.abs(obj - expected) <= delta
+      , 'expected #{this} to be close to ' + expected + ' +/- ' + delta
+      , 'expected #{this} not to be close to ' + expected + ' +/- ' + delta
+    );
+  }
+
+  Assertion.addMethod('closeTo', closeTo);
+  Assertion.addMethod('approximately', closeTo);
+
+  function isSubsetOf(subset, superset, cmp) {
+    return subset.every(function(elem) {
+      if (!cmp) return superset.indexOf(elem) !== -1;
+
+      return superset.some(function(elem2) {
+        return cmp(elem, elem2);
+      });
+    })
+  }
+
+  /**
+   * ### .members(set)
+   *
+   * Asserts that the target is a superset of `set`,
+   * or that the target and `set` have the same strictly-equal (===) members.
+   * Alternately, if the `deep` flag is set, set members are compared for deep
+   * equality.
+   *
+   *     expect([1, 2, 3]).to.include.members([3, 2]);
+   *     expect([1, 2, 3]).to.not.include.members([3, 2, 8]);
+   *
+   *     expect([4, 2]).to.have.members([2, 4]);
+   *     expect([5, 2]).to.not.have.members([5, 2, 1]);
+   *
+   *     expect([{ id: 1 }]).to.deep.include.members([{ id: 1 }]);
+   *
+   * @name members
+   * @param {Array} set
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  Assertion.addMethod('members', function (subset, msg) {
+    if (msg) flag(this, 'message', msg);
+    var obj = flag(this, 'object');
+
+    new Assertion(obj).to.be.an('array');
+    new Assertion(subset).to.be.an('array');
+
+    var cmp = flag(this, 'deep') ? _.eql : undefined;
+
+    if (flag(this, 'contains')) {
+      return this.assert(
+          isSubsetOf(subset, obj, cmp)
+        , 'expected #{this} to be a superset of #{act}'
+        , 'expected #{this} to not be a superset of #{act}'
+        , obj
+        , subset
+      );
+    }
+
+    this.assert(
+        isSubsetOf(obj, subset, cmp) && isSubsetOf(subset, obj, cmp)
+        , 'expected #{this} to have the same members as #{act}'
+        , 'expected #{this} to not have the same members as #{act}'
+        , obj
+        , subset
+    );
+  });
+
+  /**
+   * ### .oneOf(list)
+   *
+   * Assert that a value appears somewhere in the top level of array `list`.
+   *
+   *     expect('a').to.be.oneOf(['a', 'b', 'c']);
+   *     expect(9).to.not.be.oneOf(['z']);
+   *     expect([3]).to.not.be.oneOf([1, 2, [3]]);
+   *
+   *     var three = [3];
+   *     // for object-types, contents are not compared
+   *     expect(three).to.not.be.oneOf([1, 2, [3]]);
+   *     // comparing references works
+   *     expect(three).to.be.oneOf([1, 2, three]);
+   *
+   * @name oneOf
+   * @param {Array<*>} list
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function oneOf (list, msg) {
+    if (msg) flag(this, 'message', msg);
+    var expected = flag(this, 'object');
+    new Assertion(list).to.be.an('array');
+
+    this.assert(
+        list.indexOf(expected) > -1
+      , 'expected #{this} to be one of #{exp}'
+      , 'expected #{this} to not be one of #{exp}'
+      , list
+      , expected
+    );
+  }
+
+  Assertion.addMethod('oneOf', oneOf);
+
+
+  /**
+   * ### .change(function)
+   *
+   * Asserts that a function changes an object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val += 3 };
+   *     var noChangeFn = function() { return 'foo' + 'bar'; }
+   *     expect(fn).to.change(obj, 'val');
+   *     expect(noChangFn).to.not.change(obj, 'val')
+   *
+   * @name change
+   * @alias changes
+   * @alias Change
+   * @param {String} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertChanges (object, prop, msg) {
+    if (msg) flag(this, 'message', msg);
+    var fn = flag(this, 'object');
+    new Assertion(object, msg).to.have.property(prop);
+    new Assertion(fn).is.a('function');
+
+    var initial = object[prop];
+    fn();
+
+    this.assert(
+      initial !== object[prop]
+      , 'expected .' + prop + ' to change'
+      , 'expected .' + prop + ' to not change'
+    );
+  }
+
+  Assertion.addChainableMethod('change', assertChanges);
+  Assertion.addChainableMethod('changes', assertChanges);
+
+  /**
+   * ### .increase(function)
+   *
+   * Asserts that a function increases an object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 15 };
+   *     expect(fn).to.increase(obj, 'val');
+   *
+   * @name increase
+   * @alias increases
+   * @alias Increase
+   * @param {String} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertIncreases (object, prop, msg) {
+    if (msg) flag(this, 'message', msg);
+    var fn = flag(this, 'object');
+    new Assertion(object, msg).to.have.property(prop);
+    new Assertion(fn).is.a('function');
+
+    var initial = object[prop];
+    fn();
+
+    this.assert(
+      object[prop] - initial > 0
+      , 'expected .' + prop + ' to increase'
+      , 'expected .' + prop + ' to not increase'
+    );
+  }
+
+  Assertion.addChainableMethod('increase', assertIncreases);
+  Assertion.addChainableMethod('increases', assertIncreases);
+
+  /**
+   * ### .decrease(function)
+   *
+   * Asserts that a function decreases an object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 5 };
+   *     expect(fn).to.decrease(obj, 'val');
+   *
+   * @name decrease
+   * @alias decreases
+   * @alias Decrease
+   * @param {String} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  function assertDecreases (object, prop, msg) {
+    if (msg) flag(this, 'message', msg);
+    var fn = flag(this, 'object');
+    new Assertion(object, msg).to.have.property(prop);
+    new Assertion(fn).is.a('function');
+
+    var initial = object[prop];
+    fn();
+
+    this.assert(
+      object[prop] - initial < 0
+      , 'expected .' + prop + ' to decrease'
+      , 'expected .' + prop + ' to not decrease'
+    );
+  }
+
+  Assertion.addChainableMethod('decrease', assertDecreases);
+  Assertion.addChainableMethod('decreases', assertDecreases);
+
+  /**
+   * ### .extensible
+   *
+   * Asserts that the target is extensible (can have new properties added to
+   * it).
+   *
+   *     var nonExtensibleObject = Object.preventExtensions({});
+   *     var sealedObject = Object.seal({});
+   *     var frozenObject = Object.freeze({});
+   *
+   *     expect({}).to.be.extensible;
+   *     expect(nonExtensibleObject).to.not.be.extensible;
+   *     expect(sealedObject).to.not.be.extensible;
+   *     expect(frozenObject).to.not.be.extensible;
+   *
+   * @name extensible
+   * @api public
+   */
+
+  Assertion.addProperty('extensible', function() {
+    var obj = flag(this, 'object');
+
+    // In ES5, if the argument to this method is not an object (a primitive), then it will cause a TypeError.
+    // In ES6, a non-object argument will be treated as if it was a non-extensible ordinary object, simply return false.
+    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isExtensible
+    // The following provides ES6 behavior when a TypeError is thrown under ES5.
+
+    var isExtensible;
+
+    try {
+      isExtensible = Object.isExtensible(obj);
+    } catch (err) {
+      if (err instanceof TypeError) isExtensible = false;
+      else throw err;
+    }
+
+    this.assert(
+      isExtensible
+      , 'expected #{this} to be extensible'
+      , 'expected #{this} to not be extensible'
+    );
+  });
+
+  /**
+   * ### .sealed
+   *
+   * Asserts that the target is sealed (cannot have new properties added to it
+   * and its existing properties cannot be removed).
+   *
+   *     var sealedObject = Object.seal({});
+   *     var frozenObject = Object.freeze({});
+   *
+   *     expect(sealedObject).to.be.sealed;
+   *     expect(frozenObject).to.be.sealed;
+   *     expect({}).to.not.be.sealed;
+   *
+   * @name sealed
+   * @api public
+   */
+
+  Assertion.addProperty('sealed', function() {
+    var obj = flag(this, 'object');
+
+    // In ES5, if the argument to this method is not an object (a primitive), then it will cause a TypeError.
+    // In ES6, a non-object argument will be treated as if it was a sealed ordinary object, simply return true.
+    // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isSealed
+    // The following provides ES6 behavior when a TypeError is thrown under ES5.
+
+    var isSealed;
+
+    try {
+      isSealed = Object.isSealed(obj);
+    } catch (err) {
+      if (err instanceof TypeError) isSealed = true;
+      else throw err;
+    }
+
+    this.assert(
+      isSealed
+      , 'expected #{this} to be sealed'
+      , 'expected #{this} to not be sealed'
+    );
+  });
+
+  /**
+   * ### .frozen
+   *
+   * Asserts that the target is frozen (cannot have new properties added to it
+   * and its existing properties cannot be modified).
+   *
+   *     var frozenObject = Object.freeze({});
+   *
+   *     expect(frozenObject).to.be.frozen;
+   *     expect({}).to.not.be.frozen;
+   *
+   * @name frozen
+   * @api public
+   */
+
+  Assertion.addProperty('frozen', function() {
+    var obj = flag(this, 'object');
+
+    // In ES5, if the argument to this method is not an object (a primitive), then it will cause a TypeError.
+    // In ES6, a non-object argument will be treated as if it was a frozen ordinary object, simply return true.
+    // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isFrozen
+    // The following provides ES6 behavior when a TypeError is thrown under ES5.
+
+    var isFrozen;
+
+    try {
+      isFrozen = Object.isFrozen(obj);
+    } catch (err) {
+      if (err instanceof TypeError) isFrozen = true;
+      else throw err;
+    }
+
+    this.assert(
+      isFrozen
+      , 'expected #{this} to be frozen'
+      , 'expected #{this} to not be frozen'
+    );
+  });
+};
+
+},{}],6:[function(require,module,exports){
+/*!
+ * chai
+ * Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+
+module.exports = function (chai, util) {
+
+  /*!
+   * Chai dependencies.
+   */
+
+  var Assertion = chai.Assertion
+    , flag = util.flag;
+
+  /*!
+   * Module export.
+   */
+
+  /**
+   * ### assert(expression, message)
+   *
+   * Write your own test expressions.
+   *
+   *     assert('foo' !== 'bar', 'foo is not bar');
+   *     assert(Array.isArray([]), 'empty arrays are arrays');
+   *
+   * @param {Mixed} expression to test for truthiness
+   * @param {String} message to display on error
+   * @name assert
+   * @api public
+   */
+
+  var assert = chai.assert = function (express, errmsg) {
+    var test = new Assertion(null, null, chai.assert);
+    test.assert(
+        express
+      , errmsg
+      , '[ negation message unavailable ]'
+    );
+  };
+
+  /**
+   * ### .fail(actual, expected, [message], [operator])
+   *
+   * Throw a failure. Node.js `assert` module-compatible.
+   *
+   * @name fail
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @param {String} operator
+   * @api public
+   */
+
+  assert.fail = function (actual, expected, message, operator) {
+    message = message || 'assert.fail()';
+    throw new chai.AssertionError(message, {
+        actual: actual
+      , expected: expected
+      , operator: operator
+    }, assert.fail);
+  };
+
+  /**
+   * ### .isOk(object, [message])
+   *
+   * Asserts that `object` is truthy.
+   *
+   *     assert.isOk('everything', 'everything is ok');
+   *     assert.isOk(false, 'this will fail');
+   *
+   * @name isOk
+   * @alias ok
+   * @param {Mixed} object to test
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isOk = function (val, msg) {
+    new Assertion(val, msg).is.ok;
+  };
+
+  /**
+   * ### .isNotOk(object, [message])
+   *
+   * Asserts that `object` is falsy.
+   *
+   *     assert.isNotOk('everything', 'this will fail');
+   *     assert.isNotOk(false, 'this will pass');
+   *
+   * @name isNotOk
+   * @alias notOk
+   * @param {Mixed} object to test
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotOk = function (val, msg) {
+    new Assertion(val, msg).is.not.ok;
+  };
+
+  /**
+   * ### .equal(actual, expected, [message])
+   *
+   * Asserts non-strict equality (`==`) of `actual` and `expected`.
+   *
+   *     assert.equal(3, '3', '== coerces values to strings');
+   *
+   * @name equal
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @api public
+   */
+
+  assert.equal = function (act, exp, msg) {
+    var test = new Assertion(act, msg, assert.equal);
+
+    test.assert(
+        exp == flag(test, 'object')
+      , 'expected #{this} to equal #{exp}'
+      , 'expected #{this} to not equal #{act}'
+      , exp
+      , act
+    );
+  };
+
+  /**
+   * ### .notEqual(actual, expected, [message])
+   *
+   * Asserts non-strict inequality (`!=`) of `actual` and `expected`.
+   *
+   *     assert.notEqual(3, 4, 'these numbers are not equal');
+   *
+   * @name notEqual
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notEqual = function (act, exp, msg) {
+    var test = new Assertion(act, msg, assert.notEqual);
+
+    test.assert(
+        exp != flag(test, 'object')
+      , 'expected #{this} to not equal #{exp}'
+      , 'expected #{this} to equal #{act}'
+      , exp
+      , act
+    );
+  };
+
+  /**
+   * ### .strictEqual(actual, expected, [message])
+   *
+   * Asserts strict equality (`===`) of `actual` and `expected`.
+   *
+   *     assert.strictEqual(true, true, 'these booleans are strictly equal');
+   *
+   * @name strictEqual
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @api public
+   */
+
+  assert.strictEqual = function (act, exp, msg) {
+    new Assertion(act, msg).to.equal(exp);
+  };
+
+  /**
+   * ### .notStrictEqual(actual, expected, [message])
+   *
+   * Asserts strict inequality (`!==`) of `actual` and `expected`.
+   *
+   *     assert.notStrictEqual(3, '3', 'no coercion for strict equality');
+   *
+   * @name notStrictEqual
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notStrictEqual = function (act, exp, msg) {
+    new Assertion(act, msg).to.not.equal(exp);
+  };
+
+  /**
+   * ### .deepEqual(actual, expected, [message])
+   *
+   * Asserts that `actual` is deeply equal to `expected`.
+   *
+   *     assert.deepEqual({ tea: 'green' }, { tea: 'green' });
+   *
+   * @name deepEqual
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @api public
+   */
+
+  assert.deepEqual = function (act, exp, msg) {
+    new Assertion(act, msg).to.eql(exp);
+  };
+
+  /**
+   * ### .notDeepEqual(actual, expected, [message])
+   *
+   * Assert that `actual` is not deeply equal to `expected`.
+   *
+   *     assert.notDeepEqual({ tea: 'green' }, { tea: 'jasmine' });
+   *
+   * @name notDeepEqual
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notDeepEqual = function (act, exp, msg) {
+    new Assertion(act, msg).to.not.eql(exp);
+  };
+
+   /**
+   * ### .isAbove(valueToCheck, valueToBeAbove, [message])
+   *
+   * Asserts `valueToCheck` is strictly greater than (>) `valueToBeAbove`
+   *
+   *     assert.isAbove(5, 2, '5 is strictly greater than 2');
+   *
+   * @name isAbove
+   * @param {Mixed} valueToCheck
+   * @param {Mixed} valueToBeAbove
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isAbove = function (val, abv, msg) {
+    new Assertion(val, msg).to.be.above(abv);
+  };
+
+   /**
+   * ### .isAtLeast(valueToCheck, valueToBeAtLeast, [message])
+   *
+   * Asserts `valueToCheck` is greater than or equal to (>=) `valueToBeAtLeast`
+   *
+   *     assert.isAtLeast(5, 2, '5 is greater or equal to 2');
+   *     assert.isAtLeast(3, 3, '3 is greater or equal to 3');
+   *
+   * @name isAtLeast
+   * @param {Mixed} valueToCheck
+   * @param {Mixed} valueToBeAtLeast
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isAtLeast = function (val, atlst, msg) {
+    new Assertion(val, msg).to.be.least(atlst);
+  };
+
+   /**
+   * ### .isBelow(valueToCheck, valueToBeBelow, [message])
+   *
+   * Asserts `valueToCheck` is strictly less than (<) `valueToBeBelow`
+   *
+   *     assert.isBelow(3, 6, '3 is strictly less than 6');
+   *
+   * @name isBelow
+   * @param {Mixed} valueToCheck
+   * @param {Mixed} valueToBeBelow
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isBelow = function (val, blw, msg) {
+    new Assertion(val, msg).to.be.below(blw);
+  };
+
+   /**
+   * ### .isAtMost(valueToCheck, valueToBeAtMost, [message])
+   *
+   * Asserts `valueToCheck` is less than or equal to (<=) `valueToBeAtMost`
+   *
+   *     assert.isAtMost(3, 6, '3 is less than or equal to 6');
+   *     assert.isAtMost(4, 4, '4 is less than or equal to 4');
+   *
+   * @name isAtMost
+   * @param {Mixed} valueToCheck
+   * @param {Mixed} valueToBeAtMost
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isAtMost = function (val, atmst, msg) {
+    new Assertion(val, msg).to.be.most(atmst);
+  };
+
+  /**
+   * ### .isTrue(value, [message])
+   *
+   * Asserts that `value` is true.
+   *
+   *     var teaServed = true;
+   *     assert.isTrue(teaServed, 'the tea has been served');
+   *
+   * @name isTrue
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isTrue = function (val, msg) {
+    new Assertion(val, msg).is['true'];
+  };
+
+  /**
+   * ### .isNotTrue(value, [message])
+   *
+   * Asserts that `value` is not true.
+   *
+   *     var tea = 'tasty chai';
+   *     assert.isNotTrue(tea, 'great, time for tea!');
+   *
+   * @name isNotTrue
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotTrue = function (val, msg) {
+    new Assertion(val, msg).to.not.equal(true);
+  };
+
+  /**
+   * ### .isFalse(value, [message])
+   *
+   * Asserts that `value` is false.
+   *
+   *     var teaServed = false;
+   *     assert.isFalse(teaServed, 'no tea yet? hmm...');
+   *
+   * @name isFalse
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isFalse = function (val, msg) {
+    new Assertion(val, msg).is['false'];
+  };
+
+  /**
+   * ### .isNotFalse(value, [message])
+   *
+   * Asserts that `value` is not false.
+   *
+   *     var tea = 'tasty chai';
+   *     assert.isNotFalse(tea, 'great, time for tea!');
+   *
+   * @name isNotFalse
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotFalse = function (val, msg) {
+    new Assertion(val, msg).to.not.equal(false);
+  };
+
+  /**
+   * ### .isNull(value, [message])
+   *
+   * Asserts that `value` is null.
+   *
+   *     assert.isNull(err, 'there was no error');
+   *
+   * @name isNull
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNull = function (val, msg) {
+    new Assertion(val, msg).to.equal(null);
+  };
+
+  /**
+   * ### .isNotNull(value, [message])
+   *
+   * Asserts that `value` is not null.
+   *
+   *     var tea = 'tasty chai';
+   *     assert.isNotNull(tea, 'great, time for tea!');
+   *
+   * @name isNotNull
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotNull = function (val, msg) {
+    new Assertion(val, msg).to.not.equal(null);
+  };
+
+  /**
+   * ### .isNaN
+   * Asserts that value is NaN
+   *
+   *    assert.isNaN('foo', 'foo is NaN');
+   *
+   * @name isNaN
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNaN = function (val, msg) {
+    new Assertion(val, msg).to.be.NaN;
+  };
+
+  /**
+   * ### .isNotNaN
+   * Asserts that value is not NaN
+   *
+   *    assert.isNotNaN(4, '4 is not NaN');
+   *
+   * @name isNotNaN
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+  assert.isNotNaN = function (val, msg) {
+    new Assertion(val, msg).not.to.be.NaN;
+  };
+
+  /**
+   * ### .isUndefined(value, [message])
+   *
+   * Asserts that `value` is `undefined`.
+   *
+   *     var tea;
+   *     assert.isUndefined(tea, 'no tea defined');
+   *
+   * @name isUndefined
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isUndefined = function (val, msg) {
+    new Assertion(val, msg).to.equal(undefined);
+  };
+
+  /**
+   * ### .isDefined(value, [message])
+   *
+   * Asserts that `value` is not `undefined`.
+   *
+   *     var tea = 'cup of chai';
+   *     assert.isDefined(tea, 'tea has been defined');
+   *
+   * @name isDefined
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isDefined = function (val, msg) {
+    new Assertion(val, msg).to.not.equal(undefined);
+  };
+
+  /**
+   * ### .isFunction(value, [message])
+   *
+   * Asserts that `value` is a function.
+   *
+   *     function serveTea() { return 'cup of tea'; };
+   *     assert.isFunction(serveTea, 'great, we can have tea now');
+   *
+   * @name isFunction
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isFunction = function (val, msg) {
+    new Assertion(val, msg).to.be.a('function');
+  };
+
+  /**
+   * ### .isNotFunction(value, [message])
+   *
+   * Asserts that `value` is _not_ a function.
+   *
+   *     var serveTea = [ 'heat', 'pour', 'sip' ];
+   *     assert.isNotFunction(serveTea, 'great, we have listed the steps');
+   *
+   * @name isNotFunction
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotFunction = function (val, msg) {
+    new Assertion(val, msg).to.not.be.a('function');
+  };
+
+  /**
+   * ### .isObject(value, [message])
+   *
+   * Asserts that `value` is an object (as revealed by
+   * `Object.prototype.toString`).
+   *
+   *     var selection = { name: 'Chai', serve: 'with spices' };
+   *     assert.isObject(selection, 'tea selection is an object');
+   *
+   * @name isObject
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isObject = function (val, msg) {
+    new Assertion(val, msg).to.be.a('object');
+  };
+
+  /**
+   * ### .isNotObject(value, [message])
+   *
+   * Asserts that `value` is _not_ an object.
+   *
+   *     var selection = 'chai'
+   *     assert.isNotObject(selection, 'tea selection is not an object');
+   *     assert.isNotObject(null, 'null is not an object');
+   *
+   * @name isNotObject
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotObject = function (val, msg) {
+    new Assertion(val, msg).to.not.be.a('object');
+  };
+
+  /**
+   * ### .isArray(value, [message])
+   *
+   * Asserts that `value` is an array.
+   *
+   *     var menu = [ 'green', 'chai', 'oolong' ];
+   *     assert.isArray(menu, 'what kind of tea do we want?');
+   *
+   * @name isArray
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isArray = function (val, msg) {
+    new Assertion(val, msg).to.be.an('array');
+  };
+
+  /**
+   * ### .isNotArray(value, [message])
+   *
+   * Asserts that `value` is _not_ an array.
+   *
+   *     var menu = 'green|chai|oolong';
+   *     assert.isNotArray(menu, 'what kind of tea do we want?');
+   *
+   * @name isNotArray
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotArray = function (val, msg) {
+    new Assertion(val, msg).to.not.be.an('array');
+  };
+
+  /**
+   * ### .isString(value, [message])
+   *
+   * Asserts that `value` is a string.
+   *
+   *     var teaOrder = 'chai';
+   *     assert.isString(teaOrder, 'order placed');
+   *
+   * @name isString
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isString = function (val, msg) {
+    new Assertion(val, msg).to.be.a('string');
+  };
+
+  /**
+   * ### .isNotString(value, [message])
+   *
+   * Asserts that `value` is _not_ a string.
+   *
+   *     var teaOrder = 4;
+   *     assert.isNotString(teaOrder, 'order placed');
+   *
+   * @name isNotString
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotString = function (val, msg) {
+    new Assertion(val, msg).to.not.be.a('string');
+  };
+
+  /**
+   * ### .isNumber(value, [message])
+   *
+   * Asserts that `value` is a number.
+   *
+   *     var cups = 2;
+   *     assert.isNumber(cups, 'how many cups');
+   *
+   * @name isNumber
+   * @param {Number} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNumber = function (val, msg) {
+    new Assertion(val, msg).to.be.a('number');
+  };
+
+  /**
+   * ### .isNotNumber(value, [message])
+   *
+   * Asserts that `value` is _not_ a number.
+   *
+   *     var cups = '2 cups please';
+   *     assert.isNotNumber(cups, 'how many cups');
+   *
+   * @name isNotNumber
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotNumber = function (val, msg) {
+    new Assertion(val, msg).to.not.be.a('number');
+  };
+
+  /**
+   * ### .isBoolean(value, [message])
+   *
+   * Asserts that `value` is a boolean.
+   *
+   *     var teaReady = true
+   *       , teaServed = false;
+   *
+   *     assert.isBoolean(teaReady, 'is the tea ready');
+   *     assert.isBoolean(teaServed, 'has tea been served');
+   *
+   * @name isBoolean
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isBoolean = function (val, msg) {
+    new Assertion(val, msg).to.be.a('boolean');
+  };
+
+  /**
+   * ### .isNotBoolean(value, [message])
+   *
+   * Asserts that `value` is _not_ a boolean.
+   *
+   *     var teaReady = 'yep'
+   *       , teaServed = 'nope';
+   *
+   *     assert.isNotBoolean(teaReady, 'is the tea ready');
+   *     assert.isNotBoolean(teaServed, 'has tea been served');
+   *
+   * @name isNotBoolean
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.isNotBoolean = function (val, msg) {
+    new Assertion(val, msg).to.not.be.a('boolean');
+  };
+
+  /**
+   * ### .typeOf(value, name, [message])
+   *
+   * Asserts that `value`'s type is `name`, as determined by
+   * `Object.prototype.toString`.
+   *
+   *     assert.typeOf({ tea: 'chai' }, 'object', 'we have an object');
+   *     assert.typeOf(['chai', 'jasmine'], 'array', 'we have an array');
+   *     assert.typeOf('tea', 'string', 'we have a string');
+   *     assert.typeOf(/tea/, 'regexp', 'we have a regular expression');
+   *     assert.typeOf(null, 'null', 'we have a null');
+   *     assert.typeOf(undefined, 'undefined', 'we have an undefined');
+   *
+   * @name typeOf
+   * @param {Mixed} value
+   * @param {String} name
+   * @param {String} message
+   * @api public
+   */
+
+  assert.typeOf = function (val, type, msg) {
+    new Assertion(val, msg).to.be.a(type);
+  };
+
+  /**
+   * ### .notTypeOf(value, name, [message])
+   *
+   * Asserts that `value`'s type is _not_ `name`, as determined by
+   * `Object.prototype.toString`.
+   *
+   *     assert.notTypeOf('tea', 'number', 'strings are not numbers');
+   *
+   * @name notTypeOf
+   * @param {Mixed} value
+   * @param {String} typeof name
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notTypeOf = function (val, type, msg) {
+    new Assertion(val, msg).to.not.be.a(type);
+  };
+
+  /**
+   * ### .instanceOf(object, constructor, [message])
+   *
+   * Asserts that `value` is an instance of `constructor`.
+   *
+   *     var Tea = function (name) { this.name = name; }
+   *       , chai = new Tea('chai');
+   *
+   *     assert.instanceOf(chai, Tea, 'chai is an instance of tea');
+   *
+   * @name instanceOf
+   * @param {Object} object
+   * @param {Constructor} constructor
+   * @param {String} message
+   * @api public
+   */
+
+  assert.instanceOf = function (val, type, msg) {
+    new Assertion(val, msg).to.be.instanceOf(type);
+  };
+
+  /**
+   * ### .notInstanceOf(object, constructor, [message])
+   *
+   * Asserts `value` is not an instance of `constructor`.
+   *
+   *     var Tea = function (name) { this.name = name; }
+   *       , chai = new String('chai');
+   *
+   *     assert.notInstanceOf(chai, Tea, 'chai is not an instance of tea');
+   *
+   * @name notInstanceOf
+   * @param {Object} object
+   * @param {Constructor} constructor
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notInstanceOf = function (val, type, msg) {
+    new Assertion(val, msg).to.not.be.instanceOf(type);
+  };
+
+  /**
+   * ### .include(haystack, needle, [message])
+   *
+   * Asserts that `haystack` includes `needle`. Works
+   * for strings and arrays.
+   *
+   *     assert.include('foobar', 'bar', 'foobar contains string "bar"');
+   *     assert.include([ 1, 2, 3 ], 3, 'array contains value');
+   *
+   * @name include
+   * @param {Array|String} haystack
+   * @param {Mixed} needle
+   * @param {String} message
+   * @api public
+   */
+
+  assert.include = function (exp, inc, msg) {
+    new Assertion(exp, msg, assert.include).include(inc);
+  };
+
+  /**
+   * ### .notInclude(haystack, needle, [message])
+   *
+   * Asserts that `haystack` does not include `needle`. Works
+   * for strings and arrays.
+   *
+   *     assert.notInclude('foobar', 'baz', 'string not include substring');
+   *     assert.notInclude([ 1, 2, 3 ], 4, 'array not include contain value');
+   *
+   * @name notInclude
+   * @param {Array|String} haystack
+   * @param {Mixed} needle
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notInclude = function (exp, inc, msg) {
+    new Assertion(exp, msg, assert.notInclude).not.include(inc);
+  };
+
+  /**
+   * ### .match(value, regexp, [message])
+   *
+   * Asserts that `value` matches the regular expression `regexp`.
+   *
+   *     assert.match('foobar', /^foo/, 'regexp matches');
+   *
+   * @name match
+   * @param {Mixed} value
+   * @param {RegExp} regexp
+   * @param {String} message
+   * @api public
+   */
+
+  assert.match = function (exp, re, msg) {
+    new Assertion(exp, msg).to.match(re);
+  };
+
+  /**
+   * ### .notMatch(value, regexp, [message])
+   *
+   * Asserts that `value` does not match the regular expression `regexp`.
+   *
+   *     assert.notMatch('foobar', /^foo/, 'regexp does not match');
+   *
+   * @name notMatch
+   * @param {Mixed} value
+   * @param {RegExp} regexp
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notMatch = function (exp, re, msg) {
+    new Assertion(exp, msg).to.not.match(re);
+  };
+
+  /**
+   * ### .property(object, property, [message])
+   *
+   * Asserts that `object` has a property named by `property`.
+   *
+   *     assert.property({ tea: { green: 'matcha' }}, 'tea');
+   *
+   * @name property
+   * @param {Object} object
+   * @param {String} property
+   * @param {String} message
+   * @api public
+   */
+
+  assert.property = function (obj, prop, msg) {
+    new Assertion(obj, msg).to.have.property(prop);
+  };
+
+  /**
+   * ### .notProperty(object, property, [message])
+   *
+   * Asserts that `object` does _not_ have a property named by `property`.
+   *
+   *     assert.notProperty({ tea: { green: 'matcha' }}, 'coffee');
+   *
+   * @name notProperty
+   * @param {Object} object
+   * @param {String} property
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notProperty = function (obj, prop, msg) {
+    new Assertion(obj, msg).to.not.have.property(prop);
+  };
+
+  /**
+   * ### .deepProperty(object, property, [message])
+   *
+   * Asserts that `object` has a property named by `property`, which can be a
+   * string using dot- and bracket-notation for deep reference.
+   *
+   *     assert.deepProperty({ tea: { green: 'matcha' }}, 'tea.green');
+   *
+   * @name deepProperty
+   * @param {Object} object
+   * @param {String} property
+   * @param {String} message
+   * @api public
+   */
+
+  assert.deepProperty = function (obj, prop, msg) {
+    new Assertion(obj, msg).to.have.deep.property(prop);
+  };
+
+  /**
+   * ### .notDeepProperty(object, property, [message])
+   *
+   * Asserts that `object` does _not_ have a property named by `property`, which
+   * can be a string using dot- and bracket-notation for deep reference.
+   *
+   *     assert.notDeepProperty({ tea: { green: 'matcha' }}, 'tea.oolong');
+   *
+   * @name notDeepProperty
+   * @param {Object} object
+   * @param {String} property
+   * @param {String} message
+   * @api public
+   */
+
+  assert.notDeepProperty = function (obj, prop, msg) {
+    new Assertion(obj, msg).to.not.have.deep.property(prop);
+  };
+
+  /**
+   * ### .propertyVal(object, property, value, [message])
+   *
+   * Asserts that `object` has a property named by `property` with value given
+   * by `value`.
+   *
+   *     assert.propertyVal({ tea: 'is good' }, 'tea', 'is good');
+   *
+   * @name propertyVal
+   * @param {Object} object
+   * @param {String} property
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.propertyVal = function (obj, prop, val, msg) {
+    new Assertion(obj, msg).to.have.property(prop, val);
+  };
+
+  /**
+   * ### .propertyNotVal(object, property, value, [message])
+   *
+   * Asserts that `object` has a property named by `property`, but with a value
+   * different from that given by `value`.
+   *
+   *     assert.propertyNotVal({ tea: 'is good' }, 'tea', 'is bad');
+   *
+   * @name propertyNotVal
+   * @param {Object} object
+   * @param {String} property
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.propertyNotVal = function (obj, prop, val, msg) {
+    new Assertion(obj, msg).to.not.have.property(prop, val);
+  };
+
+  /**
+   * ### .deepPropertyVal(object, property, value, [message])
+   *
+   * Asserts that `object` has a property named by `property` with value given
+   * by `value`. `property` can use dot- and bracket-notation for deep
+   * reference.
+   *
+   *     assert.deepPropertyVal({ tea: { green: 'matcha' }}, 'tea.green', 'matcha');
+   *
+   * @name deepPropertyVal
+   * @param {Object} object
+   * @param {String} property
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.deepPropertyVal = function (obj, prop, val, msg) {
+    new Assertion(obj, msg).to.have.deep.property(prop, val);
+  };
+
+  /**
+   * ### .deepPropertyNotVal(object, property, value, [message])
+   *
+   * Asserts that `object` has a property named by `property`, but with a value
+   * different from that given by `value`. `property` can use dot- and
+   * bracket-notation for deep reference.
+   *
+   *     assert.deepPropertyNotVal({ tea: { green: 'matcha' }}, 'tea.green', 'konacha');
+   *
+   * @name deepPropertyNotVal
+   * @param {Object} object
+   * @param {String} property
+   * @param {Mixed} value
+   * @param {String} message
+   * @api public
+   */
+
+  assert.deepPropertyNotVal = function (obj, prop, val, msg) {
+    new Assertion(obj, msg).to.not.have.deep.property(prop, val);
+  };
+
+  /**
+   * ### .lengthOf(object, length, [message])
+   *
+   * Asserts that `object` has a `length` property with the expected value.
+   *
+   *     assert.lengthOf([1,2,3], 3, 'array has length of 3');
+   *     assert.lengthOf('foobar', 6, 'string has length of 6');
+   *
+   * @name lengthOf
+   * @param {Mixed} object
+   * @param {Number} length
+   * @param {String} message
+   * @api public
+   */
+
+  assert.lengthOf = function (exp, len, msg) {
+    new Assertion(exp, msg).to.have.length(len);
+  };
+
+  /**
+   * ### .throws(function, [constructor/string/regexp], [string/regexp], [message])
+   *
+   * Asserts that `function` will throw an error that is an instance of
+   * `constructor`, or alternately that it will throw an error with message
+   * matching `regexp`.
+   *
+   *     assert.throws(fn, 'function throws a reference error');
+   *     assert.throws(fn, /function throws a reference error/);
+   *     assert.throws(fn, ReferenceError);
+   *     assert.throws(fn, ReferenceError, 'function throws a reference error');
+   *     assert.throws(fn, ReferenceError, /function throws a reference error/);
+   *
+   * @name throws
+   * @alias throw
+   * @alias Throw
+   * @param {Function} function
+   * @param {ErrorConstructor} constructor
+   * @param {RegExp} regexp
+   * @param {String} message
+   * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
+   * @api public
+   */
+
+  assert.throws = function (fn, errt, errs, msg) {
+    if ('string' === typeof errt || errt instanceof RegExp) {
+      errs = errt;
+      errt = null;
+    }
+
+    var assertErr = new Assertion(fn, msg).to.throw(errt, errs);
+    return flag(assertErr, 'object');
+  };
+
+  /**
+   * ### .doesNotThrow(function, [constructor/regexp], [message])
+   *
+   * Asserts that `function` will _not_ throw an error that is an instance of
+   * `constructor`, or alternately that it will not throw an error with message
+   * matching `regexp`.
+   *
+   *     assert.doesNotThrow(fn, Error, 'function does not throw');
+   *
+   * @name doesNotThrow
+   * @param {Function} function
+   * @param {ErrorConstructor} constructor
+   * @param {RegExp} regexp
+   * @param {String} message
+   * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
+   * @api public
+   */
+
+  assert.doesNotThrow = function (fn, type, msg) {
+    if ('string' === typeof type) {
+      msg = type;
+      type = null;
+    }
+
+    new Assertion(fn, msg).to.not.Throw(type);
+  };
+
+  /**
+   * ### .operator(val1, operator, val2, [message])
+   *
+   * Compares two values using `operator`.
+   *
+   *     assert.operator(1, '<', 2, 'everything is ok');
+   *     assert.operator(1, '>', 2, 'this will fail');
+   *
+   * @name operator
+   * @param {Mixed} val1
+   * @param {String} operator
+   * @param {Mixed} val2
+   * @param {String} message
+   * @api public
+   */
+
+  assert.operator = function (val, operator, val2, msg) {
+    var ok;
+    switch(operator) {
+      case '==':
+        ok = val == val2;
+        break;
+      case '===':
+        ok = val === val2;
+        break;
+      case '>':
+        ok = val > val2;
+        break;
+      case '>=':
+        ok = val >= val2;
+        break;
+      case '<':
+        ok = val < val2;
+        break;
+      case '<=':
+        ok = val <= val2;
+        break;
+      case '!=':
+        ok = val != val2;
+        break;
+      case '!==':
+        ok = val !== val2;
+        break;
+      default:
+        throw new Error('Invalid operator "' + operator + '"');
+    }
+    var test = new Assertion(ok, msg);
+    test.assert(
+        true === flag(test, 'object')
+      , 'expected ' + util.inspect(val) + ' to be ' + operator + ' ' + util.inspect(val2)
+      , 'expected ' + util.inspect(val) + ' to not be ' + operator + ' ' + util.inspect(val2) );
+  };
+
+  /**
+   * ### .closeTo(actual, expected, delta, [message])
+   *
+   * Asserts that the target is equal `expected`, to within a +/- `delta` range.
+   *
+   *     assert.closeTo(1.5, 1, 0.5, 'numbers are close');
+   *
+   * @name closeTo
+   * @param {Number} actual
+   * @param {Number} expected
+   * @param {Number} delta
+   * @param {String} message
+   * @api public
+   */
+
+  assert.closeTo = function (act, exp, delta, msg) {
+    new Assertion(act, msg).to.be.closeTo(exp, delta);
+  };
+
+  /**
+   * ### .approximately(actual, expected, delta, [message])
+   *
+   * Asserts that the target is equal `expected`, to within a +/- `delta` range.
+   *
+   *     assert.approximately(1.5, 1, 0.5, 'numbers are close');
+   *
+   * @name approximately
+   * @param {Number} actual
+   * @param {Number} expected
+   * @param {Number} delta
+   * @param {String} message
+   * @api public
+   */
+
+  assert.approximately = function (act, exp, delta, msg) {
+    new Assertion(act, msg).to.be.approximately(exp, delta);
+  };
+
+  /**
+   * ### .sameMembers(set1, set2, [message])
+   *
+   * Asserts that `set1` and `set2` have the same members.
+   * Order is not taken into account.
+   *
+   *     assert.sameMembers([ 1, 2, 3 ], [ 2, 1, 3 ], 'same members');
+   *
+   * @name sameMembers
+   * @param {Array} set1
+   * @param {Array} set2
+   * @param {String} message
+   * @api public
+   */
+
+  assert.sameMembers = function (set1, set2, msg) {
+    new Assertion(set1, msg).to.have.same.members(set2);
+  }
+
+  /**
+   * ### .sameDeepMembers(set1, set2, [message])
+   *
+   * Asserts that `set1` and `set2` have the same members - using a deep equality checking.
+   * Order is not taken into account.
+   *
+   *     assert.sameDeepMembers([ {b: 3}, {a: 2}, {c: 5} ], [ {c: 5}, {b: 3}, {a: 2} ], 'same deep members');
+   *
+   * @name sameDeepMembers
+   * @param {Array} set1
+   * @param {Array} set2
+   * @param {String} message
+   * @api public
+   */
+
+  assert.sameDeepMembers = function (set1, set2, msg) {
+    new Assertion(set1, msg).to.have.same.deep.members(set2);
+  }
+
+  /**
+   * ### .includeMembers(superset, subset, [message])
+   *
+   * Asserts that `subset` is included in `superset`.
+   * Order is not taken into account.
+   *
+   *     assert.includeMembers([ 1, 2, 3 ], [ 2, 1 ], 'include members');
+   *
+   * @name includeMembers
+   * @param {Array} superset
+   * @param {Array} subset
+   * @param {String} message
+   * @api public
+   */
+
+  assert.includeMembers = function (superset, subset, msg) {
+    new Assertion(superset, msg).to.include.members(subset);
+  }
+
+  /**
+   * ### .oneOf(inList, list, [message])
+   *
+   * Asserts that non-object, non-array value `inList` appears in the flat array `list`.
+   *
+   *     assert.oneOf(1, [ 2, 1 ], 'Not found in list');
+   *
+   * @name oneOf
+   * @param {*} inList
+   * @param {Array<*>} list
+   * @param {String} message
+   * @api public
+   */
+
+  assert.oneOf = function (inList, list, msg) {
+    new Assertion(inList, msg).to.be.oneOf(list);
+  }
+
+   /**
+   * ### .changes(function, object, property)
+   *
+   * Asserts that a function changes the value of a property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 22 };
+   *     assert.changes(fn, obj, 'val');
+   *
+   * @name changes
+   * @param {Function} modifier function
+   * @param {Object} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.changes = function (fn, obj, prop) {
+    new Assertion(fn).to.change(obj, prop);
+  }
+
+   /**
+   * ### .doesNotChange(function, object, property)
+   *
+   * Asserts that a function does not changes the value of a property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { console.log('foo'); };
+   *     assert.doesNotChange(fn, obj, 'val');
+   *
+   * @name doesNotChange
+   * @param {Function} modifier function
+   * @param {Object} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.doesNotChange = function (fn, obj, prop) {
+    new Assertion(fn).to.not.change(obj, prop);
+  }
+
+   /**
+   * ### .increases(function, object, property)
+   *
+   * Asserts that a function increases an object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 13 };
+   *     assert.increases(fn, obj, 'val');
+   *
+   * @name increases
+   * @param {Function} modifier function
+   * @param {Object} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.increases = function (fn, obj, prop) {
+    new Assertion(fn).to.increase(obj, prop);
+  }
+
+   /**
+   * ### .doesNotIncrease(function, object, property)
+   *
+   * Asserts that a function does not increase object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 8 };
+   *     assert.doesNotIncrease(fn, obj, 'val');
+   *
+   * @name doesNotIncrease
+   * @param {Function} modifier function
+   * @param {Object} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.doesNotIncrease = function (fn, obj, prop) {
+    new Assertion(fn).to.not.increase(obj, prop);
+  }
+
+   /**
+   * ### .decreases(function, object, property)
+   *
+   * Asserts that a function decreases an object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 5 };
+   *     assert.decreases(fn, obj, 'val');
+   *
+   * @name decreases
+   * @param {Function} modifier function
+   * @param {Object} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.decreases = function (fn, obj, prop) {
+    new Assertion(fn).to.decrease(obj, prop);
+  }
+
+   /**
+   * ### .doesNotDecrease(function, object, property)
+   *
+   * Asserts that a function does not decreases an object property
+   *
+   *     var obj = { val: 10 };
+   *     var fn = function() { obj.val = 15 };
+   *     assert.doesNotDecrease(fn, obj, 'val');
+   *
+   * @name doesNotDecrease
+   * @param {Function} modifier function
+   * @param {Object} object
+   * @param {String} property name
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.doesNotDecrease = function (fn, obj, prop) {
+    new Assertion(fn).to.not.decrease(obj, prop);
+  }
+
+  /*!
+   * ### .ifError(object)
+   *
+   * Asserts if value is not a false value, and throws if it is a true value.
+   * This is added to allow for chai to be a drop-in replacement for Node's
+   * assert class.
+   *
+   *     var err = new Error('I am a custom error');
+   *     assert.ifError(err); // Rethrows err!
+   *
+   * @name ifError
+   * @param {Object} object
+   * @api public
+   */
+
+  assert.ifError = function (val) {
+    if (val) {
+      throw(val);
+    }
+  };
+
+  /**
+   * ### .isExtensible(object)
+   *
+   * Asserts that `object` is extensible (can have new properties added to it).
+   *
+   *     assert.isExtensible({});
+   *
+   * @name isExtensible
+   * @alias extensible
+   * @param {Object} object
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.isExtensible = function (obj, msg) {
+    new Assertion(obj, msg).to.be.extensible;
+  };
+
+  /**
+   * ### .isNotExtensible(object)
+   *
+   * Asserts that `object` is _not_ extensible.
+   *
+   *     var nonExtensibleObject = Object.preventExtensions({});
+   *     var sealedObject = Object.seal({});
+   *     var frozenObject = Object.freese({});
+   *
+   *     assert.isNotExtensible(nonExtensibleObject);
+   *     assert.isNotExtensible(sealedObject);
+   *     assert.isNotExtensible(frozenObject);
+   *
+   * @name isNotExtensible
+   * @alias notExtensible
+   * @param {Object} object
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.isNotExtensible = function (obj, msg) {
+    new Assertion(obj, msg).to.not.be.extensible;
+  };
+
+  /**
+   * ### .isSealed(object)
+   *
+   * Asserts that `object` is sealed (cannot have new properties added to it
+   * and its existing properties cannot be removed).
+   *
+   *     var sealedObject = Object.seal({});
+   *     var frozenObject = Object.seal({});
+   *
+   *     assert.isSealed(sealedObject);
+   *     assert.isSealed(frozenObject);
+   *
+   * @name isSealed
+   * @alias sealed
+   * @param {Object} object
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.isSealed = function (obj, msg) {
+    new Assertion(obj, msg).to.be.sealed;
+  };
+
+  /**
+   * ### .isNotSealed(object)
+   *
+   * Asserts that `object` is _not_ sealed.
+   *
+   *     assert.isNotSealed({});
+   *
+   * @name isNotSealed
+   * @alias notSealed
+   * @param {Object} object
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.isNotSealed = function (obj, msg) {
+    new Assertion(obj, msg).to.not.be.sealed;
+  };
+
+  /**
+   * ### .isFrozen(object)
+   *
+   * Asserts that `object` is frozen (cannot have new properties added to it
+   * and its existing properties cannot be modified).
+   *
+   *     var frozenObject = Object.freeze({});
+   *     assert.frozen(frozenObject);
+   *
+   * @name isFrozen
+   * @alias frozen
+   * @param {Object} object
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.isFrozen = function (obj, msg) {
+    new Assertion(obj, msg).to.be.frozen;
+  };
+
+  /**
+   * ### .isNotFrozen(object)
+   *
+   * Asserts that `object` is _not_ frozen.
+   *
+   *     assert.isNotFrozen({});
+   *
+   * @name isNotFrozen
+   * @alias notFrozen
+   * @param {Object} object
+   * @param {String} message _optional_
+   * @api public
+   */
+
+  assert.isNotFrozen = function (obj, msg) {
+    new Assertion(obj, msg).to.not.be.frozen;
+  };
+
+  /*!
+   * Aliases.
+   */
+
+  (function alias(name, as){
+    assert[as] = assert[name];
+    return alias;
+  })
+  ('isOk', 'ok')
+  ('isNotOk', 'notOk')
+  ('throws', 'throw')
+  ('throws', 'Throw')
+  ('isExtensible', 'extensible')
+  ('isNotExtensible', 'notExtensible')
+  ('isSealed', 'sealed')
+  ('isNotSealed', 'notSealed')
+  ('isFrozen', 'frozen')
+  ('isNotFrozen', 'notFrozen');
+};
+
+},{}],7:[function(require,module,exports){
+/*!
+ * chai
+ * Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+module.exports = function (chai, util) {
+  chai.expect = function (val, message) {
+    return new chai.Assertion(val, message);
+  };
+
+  /**
+   * ### .fail(actual, expected, [message], [operator])
+   *
+   * Throw a failure.
+   *
+   * @name fail
+   * @param {Mixed} actual
+   * @param {Mixed} expected
+   * @param {String} message
+   * @param {String} operator
+   * @api public
+   */
+
+  chai.expect.fail = function (actual, expected, message, operator) {
+    message = message || 'expect.fail()';
+    throw new chai.AssertionError(message, {
+        actual: actual
+      , expected: expected
+      , operator: operator
+    }, chai.expect.fail);
+  };
+};
+
+},{}],8:[function(require,module,exports){
+/*!
+ * chai
+ * Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+module.exports = function (chai, util) {
+  var Assertion = chai.Assertion;
+
+  function loadShould () {
+    // explicitly define this method as function as to have it's name to include as `ssfi`
+    function shouldGetter() {
+      if (this instanceof String || this instanceof Number || this instanceof Boolean ) {
+        return new Assertion(this.valueOf(), null, shouldGetter);
+      }
+      return new Assertion(this, null, shouldGetter);
+    }
+    function shouldSetter(value) {
+      // See https://github.com/chaijs/chai/issues/86: this makes
+      // `whatever.should = someValue` actually set `someValue`, which is
+      // especially useful for `global.should = require('chai').should()`.
+      //
+      // Note that we have to use [[DefineProperty]] instead of [[Put]]
+      // since otherwise we would trigger this very setter!
+      Object.defineProperty(this, 'should', {
+        value: value,
+        enumerable: true,
+        configurable: true,
+        writable: true
+      });
+    }
+    // modify Object.prototype to have `should`
+    Object.defineProperty(Object.prototype, 'should', {
+      set: shouldSetter
+      , get: shouldGetter
+      , configurable: true
+    });
+
+    var should = {};
+
+    /**
+     * ### .fail(actual, expected, [message], [operator])
+     *
+     * Throw a failure.
+     *
+     * @name fail
+     * @param {Mixed} actual
+     * @param {Mixed} expected
+     * @param {String} message
+     * @param {String} operator
+     * @api public
+     */
+
+    should.fail = function (actual, expected, message, operator) {
+      message = message || 'should.fail()';
+      throw new chai.AssertionError(message, {
+          actual: actual
+        , expected: expected
+        , operator: operator
+      }, should.fail);
+    };
+
+    should.equal = function (val1, val2, msg) {
+      new Assertion(val1, msg).to.equal(val2);
+    };
+
+    should.Throw = function (fn, errt, errs, msg) {
+      new Assertion(fn, msg).to.Throw(errt, errs);
+    };
+
+    should.exist = function (val, msg) {
+      new Assertion(val, msg).to.exist;
+    }
+
+    // negation
+    should.not = {}
+
+    should.not.equal = function (val1, val2, msg) {
+      new Assertion(val1, msg).to.not.equal(val2);
+    };
+
+    should.not.Throw = function (fn, errt, errs, msg) {
+      new Assertion(fn, msg).to.not.Throw(errt, errs);
+    };
+
+    should.not.exist = function (val, msg) {
+      new Assertion(val, msg).to.not.exist;
+    }
+
+    should['throw'] = should['Throw'];
+    should.not['throw'] = should.not['Throw'];
+
+    return should;
+  };
+
+  chai.should = loadShould;
+  chai.Should = loadShould;
+};
+
+},{}],9:[function(require,module,exports){
+/*!
+ * Chai - addChainingMethod utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Module dependencies
+ */
+
+var transferFlags = require('./transferFlags');
+var flag = require('./flag');
+var config = require('../config');
+
+/*!
+ * Module variables
+ */
+
+// Check whether `__proto__` is supported
+var hasProtoSupport = '__proto__' in Object;
+
+// Without `__proto__` support, this module will need to add properties to a function.
+// However, some Function.prototype methods cannot be overwritten,
+// and there seems no easy cross-platform way to detect them (@see chaijs/chai/issues/69).
+var excludeNames = /^(?:length|name|arguments|caller)$/;
+
+// Cache `Function` properties
+var call  = Function.prototype.call,
+    apply = Function.prototype.apply;
+
+/**
+ * ### addChainableMethod (ctx, name, method, chainingBehavior)
+ *
+ * Adds a method to an object, such that the method can also be chained.
+ *
+ *     utils.addChainableMethod(chai.Assertion.prototype, 'foo', function (str) {
+ *       var obj = utils.flag(this, 'object');
+ *       new chai.Assertion(obj).to.be.equal(str);
+ *     });
+ *
+ * Can also be accessed directly from `chai.Assertion`.
+ *
+ *     chai.Assertion.addChainableMethod('foo', fn, chainingBehavior);
+ *
+ * The result can then be used as both a method assertion, executing both `method` and
+ * `chainingBehavior`, or as a language chain, which only executes `chainingBehavior`.
+ *
+ *     expect(fooStr).to.be.foo('bar');
+ *     expect(fooStr).to.be.foo.equal('foo');
+ *
+ * @param {Object} ctx object to which the method is added
+ * @param {String} name of method to add
+ * @param {Function} method function to be used for `name`, when called
+ * @param {Function} chainingBehavior function to be called every time the property is accessed
+ * @name addChainableMethod
+ * @api public
+ */
+
+module.exports = function (ctx, name, method, chainingBehavior) {
+  if (typeof chainingBehavior !== 'function') {
+    chainingBehavior = function () { };
+  }
+
+  var chainableBehavior = {
+      method: method
+    , chainingBehavior: chainingBehavior
+  };
+
+  // save the methods so we can overwrite them later, if we need to.
+  if (!ctx.__methods) {
+    ctx.__methods = {};
+  }
+  ctx.__methods[name] = chainableBehavior;
+
+  Object.defineProperty(ctx, name,
+    { get: function () {
+        chainableBehavior.chainingBehavior.call(this);
+
+        var assert = function assert() {
+          var old_ssfi = flag(this, 'ssfi');
+          if (old_ssfi && config.includeStack === false)
+            flag(this, 'ssfi', assert);
+          var result = chainableBehavior.method.apply(this, arguments);
+          return result === undefined ? this : result;
+        };
+
+        // Use `__proto__` if available
+        if (hasProtoSupport) {
+          // Inherit all properties from the object by replacing the `Function` prototype
+          var prototype = assert.__proto__ = Object.create(this);
+          // Restore the `call` and `apply` methods from `Function`
+          prototype.call = call;
+          prototype.apply = apply;
+        }
+        // Otherwise, redefine all properties (slow!)
+        else {
+          var asserterNames = Object.getOwnPropertyNames(ctx);
+          asserterNames.forEach(function (asserterName) {
+            if (!excludeNames.test(asserterName)) {
+              var pd = Object.getOwnPropertyDescriptor(ctx, asserterName);
+              Object.defineProperty(assert, asserterName, pd);
+            }
+          });
+        }
+
+        transferFlags(this, assert);
+        return assert;
+      }
+    , configurable: true
+  });
+};
+
+},{"../config":4,"./flag":13,"./transferFlags":29}],10:[function(require,module,exports){
+/*!
+ * Chai - addMethod utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+var config = require('../config');
+
+/**
+ * ### .addMethod (ctx, name, method)
+ *
+ * Adds a method to the prototype of an object.
+ *
+ *     utils.addMethod(chai.Assertion.prototype, 'foo', function (str) {
+ *       var obj = utils.flag(this, 'object');
+ *       new chai.Assertion(obj).to.be.equal(str);
+ *     });
+ *
+ * Can also be accessed directly from `chai.Assertion`.
+ *
+ *     chai.Assertion.addMethod('foo', fn);
+ *
+ * Then can be used as any other assertion.
+ *
+ *     expect(fooStr).to.be.foo('bar');
+ *
+ * @param {Object} ctx object to which the method is added
+ * @param {String} name of method to add
+ * @param {Function} method function to be used for name
+ * @name addMethod
+ * @api public
+ */
+var flag = require('./flag');
+
+module.exports = function (ctx, name, method) {
+  ctx[name] = function () {
+    var old_ssfi = flag(this, 'ssfi');
+    if (old_ssfi && config.includeStack === false)
+      flag(this, 'ssfi', ctx[name]);
+    var result = method.apply(this, arguments);
+    return result === undefined ? this : result;
+  };
+};
+
+},{"../config":4,"./flag":13}],11:[function(require,module,exports){
+/*!
+ * Chai - addProperty utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+var config = require('../config');
+var flag = require('./flag');
+
+/**
+ * ### addProperty (ctx, name, getter)
+ *
+ * Adds a property to the prototype of an object.
+ *
+ *     utils.addProperty(chai.Assertion.prototype, 'foo', function () {
+ *       var obj = utils.flag(this, 'object');
+ *       new chai.Assertion(obj).to.be.instanceof(Foo);
+ *     });
+ *
+ * Can also be accessed directly from `chai.Assertion`.
+ *
+ *     chai.Assertion.addProperty('foo', fn);
+ *
+ * Then can be used as any other assertion.
+ *
+ *     expect(myFoo).to.be.foo;
+ *
+ * @param {Object} ctx object to which the property is added
+ * @param {String} name of property to add
+ * @param {Function} getter function to be used for name
+ * @name addProperty
+ * @api public
+ */
+
+module.exports = function (ctx, name, getter) {
+  Object.defineProperty(ctx, name,
+    { get: function addProperty() {
+        var old_ssfi = flag(this, 'ssfi');
+        if (old_ssfi && config.includeStack === false)
+          flag(this, 'ssfi', addProperty);
+
+        var result = getter.call(this);
+        return result === undefined ? this : result;
+      }
+    , configurable: true
+  });
+};
+
+},{"../config":4,"./flag":13}],12:[function(require,module,exports){
+/*!
+ * Chai - expectTypes utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### expectTypes(obj, types)
+ *
+ * Ensures that the object being tested against is of a valid type.
+ *
+ *     utils.expectTypes(this, ['array', 'object', 'string']);
+ *
+ * @param {Mixed} obj constructed Assertion
+ * @param {Array} type A list of allowed types for this assertion
+ * @name expectTypes
+ * @api public
+ */
+
+var AssertionError = require('assertion-error');
+var flag = require('./flag');
+var type = require('type-detect');
+
+module.exports = function (obj, types) {
+  var obj = flag(obj, 'object');
+  types = types.map(function (t) { return t.toLowerCase(); });
+  types.sort();
+
+  // Transforms ['lorem', 'ipsum'] into 'a lirum, or an ipsum'
+  var str = types.map(function (t, index) {
+    var art = ~[ 'a', 'e', 'i', 'o', 'u' ].indexOf(t.charAt(0)) ? 'an' : 'a';
+    var or = types.length > 1 && index === types.length - 1 ? 'or ' : '';
+    return or + art + ' ' + t;
+  }).join(', ');
+
+  if (!types.some(function (expected) { return type(obj) === expected; })) {
+    throw new AssertionError(
+      'object tested must be ' + str + ', but ' + type(obj) + ' given'
+    );
+  }
+};
+
+},{"./flag":13,"assertion-error":30,"type-detect":35}],13:[function(require,module,exports){
+/*!
+ * Chai - flag utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### flag(object, key, [value])
+ *
+ * Get or set a flag value on an object. If a
+ * value is provided it will be set, else it will
+ * return the currently set value or `undefined` if
+ * the value is not set.
+ *
+ *     utils.flag(this, 'foo', 'bar'); // setter
+ *     utils.flag(this, 'foo'); // getter, returns `bar`
+ *
+ * @param {Object} object constructed Assertion
+ * @param {String} key
+ * @param {Mixed} value (optional)
+ * @name flag
+ * @api private
+ */
+
+module.exports = function (obj, key, value) {
+  var flags = obj.__flags || (obj.__flags = Object.create(null));
+  if (arguments.length === 3) {
+    flags[key] = value;
+  } else {
+    return flags[key];
+  }
+};
+
+},{}],14:[function(require,module,exports){
+/*!
+ * Chai - getActual utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * # getActual(object, [actual])
+ *
+ * Returns the `actual` value for an Assertion
+ *
+ * @param {Object} object (constructed Assertion)
+ * @param {Arguments} chai.Assertion.prototype.assert arguments
+ */
+
+module.exports = function (obj, args) {
+  return args.length > 4 ? args[4] : obj._obj;
+};
+
+},{}],15:[function(require,module,exports){
+/*!
+ * Chai - getEnumerableProperties utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### .getEnumerableProperties(object)
+ *
+ * This allows the retrieval of enumerable property names of an object,
+ * inherited or not.
+ *
+ * @param {Object} object
+ * @returns {Array}
+ * @name getEnumerableProperties
+ * @api public
+ */
+
+module.exports = function getEnumerableProperties(object) {
+  var result = [];
+  for (var name in object) {
+    result.push(name);
+  }
+  return result;
+};
+
+},{}],16:[function(require,module,exports){
+/*!
+ * Chai - message composition utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Module dependancies
+ */
+
+var flag = require('./flag')
+  , getActual = require('./getActual')
+  , inspect = require('./inspect')
+  , objDisplay = require('./objDisplay');
+
+/**
+ * ### .getMessage(object, message, negateMessage)
+ *
+ * Construct the error message based on flags
+ * and template tags. Template tags will return
+ * a stringified inspection of the object referenced.
+ *
+ * Message template tags:
+ * - `#{this}` current asserted object
+ * - `#{act}` actual value
+ * - `#{exp}` expected value
+ *
+ * @param {Object} object (constructed Assertion)
+ * @param {Arguments} chai.Assertion.prototype.assert arguments
+ * @name getMessage
+ * @api public
+ */
+
+module.exports = function (obj, args) {
+  var negate = flag(obj, 'negate')
+    , val = flag(obj, 'object')
+    , expected = args[3]
+    , actual = getActual(obj, args)
+    , msg = negate ? args[2] : args[1]
+    , flagMsg = flag(obj, 'message');
+
+  if(typeof msg === "function") msg = msg();
+  msg = msg || '';
+  msg = msg
+    .replace(/#{this}/g, objDisplay(val))
+    .replace(/#{act}/g, objDisplay(actual))
+    .replace(/#{exp}/g, objDisplay(expected));
+
+  return flagMsg ? flagMsg + ': ' + msg : msg;
+};
+
+},{"./flag":13,"./getActual":14,"./inspect":23,"./objDisplay":24}],17:[function(require,module,exports){
+/*!
+ * Chai - getName utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * # getName(func)
+ *
+ * Gets the name of a function, in a cross-browser way.
+ *
+ * @param {Function} a function (usually a constructor)
+ */
+
+module.exports = function (func) {
+  if (func.name) return func.name;
+
+  var match = /^\s?function ([^(]*)\(/.exec(func);
+  return match && match[1] ? match[1] : "";
+};
+
+},{}],18:[function(require,module,exports){
+/*!
+ * Chai - getPathInfo utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+var hasProperty = require('./hasProperty');
+
+/**
+ * ### .getPathInfo(path, object)
+ *
+ * This allows the retrieval of property info in an
+ * object given a string path.
+ *
+ * The path info consists of an object with the
+ * following properties:
+ *
+ * * parent - The parent object of the property referenced by `path`
+ * * name - The name of the final property, a number if it was an array indexer
+ * * value - The value of the property, if it exists, otherwise `undefined`
+ * * exists - Whether the property exists or not
+ *
+ * @param {String} path
+ * @param {Object} object
+ * @returns {Object} info
+ * @name getPathInfo
+ * @api public
+ */
+
+module.exports = function getPathInfo(path, obj) {
+  var parsed = parsePath(path),
+      last = parsed[parsed.length - 1];
+
+  var info = {
+    parent: parsed.length > 1 ? _getPathValue(parsed, obj, parsed.length - 1) : obj,
+    name: last.p || last.i,
+    value: _getPathValue(parsed, obj)
+  };
+  info.exists = hasProperty(info.name, info.parent);
+
+  return info;
+};
+
+
+/*!
+ * ## parsePath(path)
+ *
+ * Helper function used to parse string object
+ * paths. Use in conjunction with `_getPathValue`.
+ *
+ *      var parsed = parsePath('myobject.property.subprop');
+ *
+ * ### Paths:
+ *
+ * * Can be as near infinitely deep and nested
+ * * Arrays are also valid using the formal `myobject.document[3].property`.
+ * * Literal dots and brackets (not delimiter) must be backslash-escaped.
+ *
+ * @param {String} path
+ * @returns {Object} parsed
+ * @api private
+ */
+
+function parsePath (path) {
+  var str = path.replace(/([^\\])\[/g, '$1.[')
+    , parts = str.match(/(\\\.|[^.]+?)+/g);
+  return parts.map(function (value) {
+    var re = /^\[(\d+)\]$/
+      , mArr = re.exec(value);
+    if (mArr) return { i: parseFloat(mArr[1]) };
+    else return { p: value.replace(/\\([.\[\]])/g, '$1') };
+  });
+}
+
+
+/*!
+ * ## _getPathValue(parsed, obj)
+ *
+ * Helper companion function for `.parsePath` that returns
+ * the value located at the parsed address.
+ *
+ *      var value = getPathValue(parsed, obj);
+ *
+ * @param {Object} parsed definition from `parsePath`.
+ * @param {Object} object to search against
+ * @param {Number} object to search against
+ * @returns {Object|Undefined} value
+ * @api private
+ */
+
+function _getPathValue (parsed, obj, index) {
+  var tmp = obj
+    , res;
+
+  index = (index === undefined ? parsed.length : index);
+
+  for (var i = 0, l = index; i < l; i++) {
+    var part = parsed[i];
+    if (tmp) {
+      if ('undefined' !== typeof part.p)
+        tmp = tmp[part.p];
+      else if ('undefined' !== typeof part.i)
+        tmp = tmp[part.i];
+      if (i == (l - 1)) res = tmp;
+    } else {
+      res = undefined;
+    }
+  }
+  return res;
+}
+
+},{"./hasProperty":21}],19:[function(require,module,exports){
+/*!
+ * Chai - getPathValue utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * @see https://github.com/logicalparadox/filtr
+ * MIT Licensed
+ */
+
+var getPathInfo = require('./getPathInfo');
+
+/**
+ * ### .getPathValue(path, object)
+ *
+ * This allows the retrieval of values in an
+ * object given a string path.
+ *
+ *     var obj = {
+ *         prop1: {
+ *             arr: ['a', 'b', 'c']
+ *           , str: 'Hello'
+ *         }
+ *       , prop2: {
+ *             arr: [ { nested: 'Universe' } ]
+ *           , str: 'Hello again!'
+ *         }
+ *     }
+ *
+ * The following would be the results.
+ *
+ *     getPathValue('prop1.str', obj); // Hello
+ *     getPathValue('prop1.att[2]', obj); // b
+ *     getPathValue('prop2.arr[0].nested', obj); // Universe
+ *
+ * @param {String} path
+ * @param {Object} object
+ * @returns {Object} value or `undefined`
+ * @name getPathValue
+ * @api public
+ */
+module.exports = function(path, obj) {
+  var info = getPathInfo(path, obj);
+  return info.value;
+}; 
+
+},{"./getPathInfo":18}],20:[function(require,module,exports){
+/*!
+ * Chai - getProperties utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### .getProperties(object)
+ *
+ * This allows the retrieval of property names of an object, enumerable or not,
+ * inherited or not.
+ *
+ * @param {Object} object
+ * @returns {Array}
+ * @name getProperties
+ * @api public
+ */
+
+module.exports = function getProperties(object) {
+  var result = Object.getOwnPropertyNames(object);
+
+  function addProperty(property) {
+    if (result.indexOf(property) === -1) {
+      result.push(property);
+    }
+  }
+
+  var proto = Object.getPrototypeOf(object);
+  while (proto !== null) {
+    Object.getOwnPropertyNames(proto).forEach(addProperty);
+    proto = Object.getPrototypeOf(proto);
+  }
+
+  return result;
+};
+
+},{}],21:[function(require,module,exports){
+/*!
+ * Chai - hasProperty utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+var type = require('type-detect');
+
+/**
+ * ### .hasProperty(object, name)
+ *
+ * This allows checking whether an object has
+ * named property or numeric array index.
+ *
+ * Basically does the same thing as the `in`
+ * operator but works properly with natives
+ * and null/undefined values.
+ *
+ *     var obj = {
+ *         arr: ['a', 'b', 'c']
+ *       , str: 'Hello'
+ *     }
+ *
+ * The following would be the results.
+ *
+ *     hasProperty('str', obj);  // true
+ *     hasProperty('constructor', obj);  // true
+ *     hasProperty('bar', obj);  // false
+ *     
+ *     hasProperty('length', obj.str); // true
+ *     hasProperty(1, obj.str);  // true
+ *     hasProperty(5, obj.str);  // false
+ *
+ *     hasProperty('length', obj.arr);  // true
+ *     hasProperty(2, obj.arr);  // true
+ *     hasProperty(3, obj.arr);  // false
+ *
+ * @param {Objuect} object
+ * @param {String|Number} name
+ * @returns {Boolean} whether it exists
+ * @name getPathInfo
+ * @api public
+ */
+
+var literals = {
+    'number': Number
+  , 'string': String
+};
+
+module.exports = function hasProperty(name, obj) {
+  var ot = type(obj);
+
+  // Bad Object, obviously no props at all
+  if(ot === 'null' || ot === 'undefined')
+    return false;
+
+  // The `in` operator does not work with certain literals
+  // box these before the check
+  if(literals[ot] && typeof obj !== 'object')
+    obj = new literals[ot](obj);
+
+  return name in obj;
+};
+
+},{"type-detect":35}],22:[function(require,module,exports){
+/*!
+ * chai
+ * Copyright(c) 2011 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Main exports
+ */
+
+var exports = module.exports = {};
+
+/*!
+ * test utility
+ */
+
+exports.test = require('./test');
+
+/*!
+ * type utility
+ */
+
+exports.type = require('type-detect');
+
+/*!
+ * expectTypes utility
+ */
+exports.expectTypes = require('./expectTypes');
+
+/*!
+ * message utility
+ */
+
+exports.getMessage = require('./getMessage');
+
+/*!
+ * actual utility
+ */
+
+exports.getActual = require('./getActual');
+
+/*!
+ * Inspect util
+ */
+
+exports.inspect = require('./inspect');
+
+/*!
+ * Object Display util
+ */
+
+exports.objDisplay = require('./objDisplay');
+
+/*!
+ * Flag utility
+ */
+
+exports.flag = require('./flag');
+
+/*!
+ * Flag transferring utility
+ */
+
+exports.transferFlags = require('./transferFlags');
+
+/*!
+ * Deep equal utility
+ */
+
+exports.eql = require('deep-eql');
+
+/*!
+ * Deep path value
+ */
+
+exports.getPathValue = require('./getPathValue');
+
+/*!
+ * Deep path info
+ */
+
+exports.getPathInfo = require('./getPathInfo');
+
+/*!
+ * Check if a property exists
+ */
+
+exports.hasProperty = require('./hasProperty');
+
+/*!
+ * Function name
+ */
+
+exports.getName = require('./getName');
+
+/*!
+ * add Property
+ */
+
+exports.addProperty = require('./addProperty');
+
+/*!
+ * add Method
+ */
+
+exports.addMethod = require('./addMethod');
+
+/*!
+ * overwrite Property
+ */
+
+exports.overwriteProperty = require('./overwriteProperty');
+
+/*!
+ * overwrite Method
+ */
+
+exports.overwriteMethod = require('./overwriteMethod');
+
+/*!
+ * Add a chainable method
+ */
+
+exports.addChainableMethod = require('./addChainableMethod');
+
+/*!
+ * Overwrite chainable method
+ */
+
+exports.overwriteChainableMethod = require('./overwriteChainableMethod');
+
+},{"./addChainableMethod":9,"./addMethod":10,"./addProperty":11,"./expectTypes":12,"./flag":13,"./getActual":14,"./getMessage":16,"./getName":17,"./getPathInfo":18,"./getPathValue":19,"./hasProperty":21,"./inspect":23,"./objDisplay":24,"./overwriteChainableMethod":25,"./overwriteMethod":26,"./overwriteProperty":27,"./test":28,"./transferFlags":29,"deep-eql":31,"type-detect":35}],23:[function(require,module,exports){
+// This is (almost) directly from Node.js utils
+// https://github.com/joyent/node/blob/f8c335d0caf47f16d31413f89aa28eda3878e3aa/lib/util.js
+
+var getName = require('./getName');
+var getProperties = require('./getProperties');
+var getEnumerableProperties = require('./getEnumerableProperties');
+
+module.exports = inspect;
+
+/**
+ * Echos the value of a value. Trys to print the value out
+ * in the best way possible given the different types.
+ *
+ * @param {Object} obj The object to print out.
+ * @param {Boolean} showHidden Flag that shows hidden (not enumerable)
+ *    properties of objects.
+ * @param {Number} depth Depth in which to descend in object. Default is 2.
+ * @param {Boolean} colors Flag to turn on ANSI escape codes to color the
+ *    output. Default is false (no coloring).
+ */
+function inspect(obj, showHidden, depth, colors) {
+  var ctx = {
+    showHidden: showHidden,
+    seen: [],
+    stylize: function (str) { return str; }
+  };
+  return formatValue(ctx, obj, (typeof depth === 'undefined' ? 2 : depth));
+}
+
+// Returns true if object is a DOM element.
+var isDOMElement = function (object) {
+  if (typeof HTMLElement === 'object') {
+    return object instanceof HTMLElement;
+  } else {
+    return object &&
+      typeof object === 'object' &&
+      object.nodeType === 1 &&
+      typeof object.nodeName === 'string';
+  }
+};
+
+function formatValue(ctx, value, recurseTimes) {
+  // Provide a hook for user-specified inspect functions.
+  // Check that value is an object with an inspect function on it
+  if (value && typeof value.inspect === 'function' &&
+      // Filter out the util module, it's inspect function is special
+      value.inspect !== exports.inspect &&
+      // Also filter out any prototype objects using the circular check.
+      !(value.constructor && value.constructor.prototype === value)) {
+    var ret = value.inspect(recurseTimes);
+    if (typeof ret !== 'string') {
+      ret = formatValue(ctx, ret, recurseTimes);
+    }
+    return ret;
+  }
+
+  // Primitive types cannot have properties
+  var primitive = formatPrimitive(ctx, value);
+  if (primitive) {
+    return primitive;
+  }
+
+  // If this is a DOM element, try to get the outer HTML.
+  if (isDOMElement(value)) {
+    if ('outerHTML' in value) {
+      return value.outerHTML;
+      // This value does not have an outerHTML attribute,
+      //   it could still be an XML element
+    } else {
+      // Attempt to serialize it
+      try {
+        if (document.xmlVersion) {
+          var xmlSerializer = new XMLSerializer();
+          return xmlSerializer.serializeToString(value);
+        } else {
+          // Firefox 11- do not support outerHTML
+          //   It does, however, support innerHTML
+          //   Use the following to render the element
+          var ns = "http://www.w3.org/1999/xhtml";
+          var container = document.createElementNS(ns, '_');
+
+          container.appendChild(value.cloneNode(false));
+          html = container.innerHTML
+            .replace('><', '>' + value.innerHTML + '<');
+          container.innerHTML = '';
+          return html;
+        }
+      } catch (err) {
+        // This could be a non-native DOM implementation,
+        //   continue with the normal flow:
+        //   printing the element as if it is an object.
+      }
+    }
+  }
+
+  // Look up the keys of the object.
+  var visibleKeys = getEnumerableProperties(value);
+  var keys = ctx.showHidden ? getProperties(value) : visibleKeys;
+
+  // Some type of object without properties can be shortcutted.
+  // In IE, errors have a single `stack` property, or if they are vanilla `Error`,
+  // a `stack` plus `description` property; ignore those for consistency.
+  if (keys.length === 0 || (isError(value) && (
+      (keys.length === 1 && keys[0] === 'stack') ||
+      (keys.length === 2 && keys[0] === 'description' && keys[1] === 'stack')
+     ))) {
+    if (typeof value === 'function') {
+      var name = getName(value);
+      var nameSuffix = name ? ': ' + name : '';
+      return ctx.stylize('[Function' + nameSuffix + ']', 'special');
+    }
+    if (isRegExp(value)) {
+      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
+    }
+    if (isDate(value)) {
+      return ctx.stylize(Date.prototype.toUTCString.call(value), 'date');
+    }
+    if (isError(value)) {
+      return formatError(value);
+    }
+  }
+
+  var base = '', array = false, braces = ['{', '}'];
+
+  // Make Array say that they are Array
+  if (isArray(value)) {
+    array = true;
+    braces = ['[', ']'];
+  }
+
+  // Make functions say that they are functions
+  if (typeof value === 'function') {
+    var name = getName(value);
+    var nameSuffix = name ? ': ' + name : '';
+    base = ' [Function' + nameSuffix + ']';
+  }
+
+  // Make RegExps say that they are RegExps
+  if (isRegExp(value)) {
+    base = ' ' + RegExp.prototype.toString.call(value);
+  }
+
+  // Make dates with properties first say the date
+  if (isDate(value)) {
+    base = ' ' + Date.prototype.toUTCString.call(value);
+  }
+
+  // Make error with message first say the error
+  if (isError(value)) {
+    return formatError(value);
+  }
+
+  if (keys.length === 0 && (!array || value.length == 0)) {
+    return braces[0] + base + braces[1];
+  }
+
+  if (recurseTimes < 0) {
+    if (isRegExp(value)) {
+      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
+    } else {
+      return ctx.stylize('[Object]', 'special');
+    }
+  }
+
+  ctx.seen.push(value);
+
+  var output;
+  if (array) {
+    output = formatArray(ctx, value, recurseTimes, visibleKeys, keys);
+  } else {
+    output = keys.map(function(key) {
+      return formatProperty(ctx, value, recurseTimes, visibleKeys, key, array);
+    });
+  }
+
+  ctx.seen.pop();
+
+  return reduceToSingleString(output, base, braces);
+}
+
+
+function formatPrimitive(ctx, value) {
+  switch (typeof value) {
+    case 'undefined':
+      return ctx.stylize('undefined', 'undefined');
+
+    case 'string':
+      var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
+                                               .replace(/'/g, "\\'")
+                                               .replace(/\\"/g, '"') + '\'';
+      return ctx.stylize(simple, 'string');
+
+    case 'number':
+      if (value === 0 && (1/value) === -Infinity) {
+        return ctx.stylize('-0', 'number');
+      }
+      return ctx.stylize('' + value, 'number');
+
+    case 'boolean':
+      return ctx.stylize('' + value, 'boolean');
+  }
+  // For some reason typeof null is "object", so special case here.
+  if (value === null) {
+    return ctx.stylize('null', 'null');
+  }
+}
+
+
+function formatError(value) {
+  return '[' + Error.prototype.toString.call(value) + ']';
+}
+
+
+function formatArray(ctx, value, recurseTimes, visibleKeys, keys) {
+  var output = [];
+  for (var i = 0, l = value.length; i < l; ++i) {
+    if (Object.prototype.hasOwnProperty.call(value, String(i))) {
+      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
+          String(i), true));
+    } else {
+      output.push('');
+    }
+  }
+  keys.forEach(function(key) {
+    if (!key.match(/^\d+$/)) {
+      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
+          key, true));
+    }
+  });
+  return output;
+}
+
+
+function formatProperty(ctx, value, recurseTimes, visibleKeys, key, array) {
+  var name, str;
+  if (value.__lookupGetter__) {
+    if (value.__lookupGetter__(key)) {
+      if (value.__lookupSetter__(key)) {
+        str = ctx.stylize('[Getter/Setter]', 'special');
+      } else {
+        str = ctx.stylize('[Getter]', 'special');
+      }
+    } else {
+      if (value.__lookupSetter__(key)) {
+        str = ctx.stylize('[Setter]', 'special');
+      }
+    }
+  }
+  if (visibleKeys.indexOf(key) < 0) {
+    name = '[' + key + ']';
+  }
+  if (!str) {
+    if (ctx.seen.indexOf(value[key]) < 0) {
+      if (recurseTimes === null) {
+        str = formatValue(ctx, value[key], null);
+      } else {
+        str = formatValue(ctx, value[key], recurseTimes - 1);
+      }
+      if (str.indexOf('\n') > -1) {
+        if (array) {
+          str = str.split('\n').map(function(line) {
+            return '  ' + line;
+          }).join('\n').substr(2);
+        } else {
+          str = '\n' + str.split('\n').map(function(line) {
+            return '   ' + line;
+          }).join('\n');
+        }
+      }
+    } else {
+      str = ctx.stylize('[Circular]', 'special');
+    }
+  }
+  if (typeof name === 'undefined') {
+    if (array && key.match(/^\d+$/)) {
+      return str;
+    }
+    name = JSON.stringify('' + key);
+    if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
+      name = name.substr(1, name.length - 2);
+      name = ctx.stylize(name, 'name');
+    } else {
+      name = name.replace(/'/g, "\\'")
+                 .replace(/\\"/g, '"')
+                 .replace(/(^"|"$)/g, "'");
+      name = ctx.stylize(name, 'string');
+    }
+  }
+
+  return name + ': ' + str;
+}
+
+
+function reduceToSingleString(output, base, braces) {
+  var numLinesEst = 0;
+  var length = output.reduce(function(prev, cur) {
+    numLinesEst++;
+    if (cur.indexOf('\n') >= 0) numLinesEst++;
+    return prev + cur.length + 1;
+  }, 0);
+
+  if (length > 60) {
+    return braces[0] +
+           (base === '' ? '' : base + '\n ') +
+           ' ' +
+           output.join(',\n  ') +
+           ' ' +
+           braces[1];
+  }
+
+  return braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];
+}
+
+function isArray(ar) {
+  return Array.isArray(ar) ||
+         (typeof ar === 'object' && objectToString(ar) === '[object Array]');
+}
+
+function isRegExp(re) {
+  return typeof re === 'object' && objectToString(re) === '[object RegExp]';
+}
+
+function isDate(d) {
+  return typeof d === 'object' && objectToString(d) === '[object Date]';
+}
+
+function isError(e) {
+  return typeof e === 'object' && objectToString(e) === '[object Error]';
+}
+
+function objectToString(o) {
+  return Object.prototype.toString.call(o);
+}
+
+},{"./getEnumerableProperties":15,"./getName":17,"./getProperties":20}],24:[function(require,module,exports){
+/*!
+ * Chai - flag utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Module dependancies
+ */
+
+var inspect = require('./inspect');
+var config = require('../config');
+
+/**
+ * ### .objDisplay (object)
+ *
+ * Determines if an object or an array matches
+ * criteria to be inspected in-line for error
+ * messages or should be truncated.
+ *
+ * @param {Mixed} javascript object to inspect
+ * @name objDisplay
+ * @api public
+ */
+
+module.exports = function (obj) {
+  var str = inspect(obj)
+    , type = Object.prototype.toString.call(obj);
+
+  if (config.truncateThreshold && str.length >= config.truncateThreshold) {
+    if (type === '[object Function]') {
+      return !obj.name || obj.name === ''
+        ? '[Function]'
+        : '[Function: ' + obj.name + ']';
+    } else if (type === '[object Array]') {
+      return '[ Array(' + obj.length + ') ]';
+    } else if (type === '[object Object]') {
+      var keys = Object.keys(obj)
+        , kstr = keys.length > 2
+          ? keys.splice(0, 2).join(', ') + ', ...'
+          : keys.join(', ');
+      return '{ Object (' + kstr + ') }';
+    } else {
+      return str;
+    }
+  } else {
+    return str;
+  }
+};
+
+},{"../config":4,"./inspect":23}],25:[function(require,module,exports){
+/*!
+ * Chai - overwriteChainableMethod utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### overwriteChainableMethod (ctx, name, method, chainingBehavior)
+ *
+ * Overwites an already existing chainable method
+ * and provides access to the previous function or
+ * property.  Must return functions to be used for
+ * name.
+ *
+ *     utils.overwriteChainableMethod(chai.Assertion.prototype, 'length',
+ *       function (_super) {
+ *       }
+ *     , function (_super) {
+ *       }
+ *     );
+ *
+ * Can also be accessed directly from `chai.Assertion`.
+ *
+ *     chai.Assertion.overwriteChainableMethod('foo', fn, fn);
+ *
+ * Then can be used as any other assertion.
+ *
+ *     expect(myFoo).to.have.length(3);
+ *     expect(myFoo).to.have.length.above(3);
+ *
+ * @param {Object} ctx object whose method / property is to be overwritten
+ * @param {String} name of method / property to overwrite
+ * @param {Function} method function that returns a function to be used for name
+ * @param {Function} chainingBehavior function that returns a function to be used for property
+ * @name overwriteChainableMethod
+ * @api public
+ */
+
+module.exports = function (ctx, name, method, chainingBehavior) {
+  var chainableBehavior = ctx.__methods[name];
+
+  var _chainingBehavior = chainableBehavior.chainingBehavior;
+  chainableBehavior.chainingBehavior = function () {
+    var result = chainingBehavior(_chainingBehavior).call(this);
+    return result === undefined ? this : result;
+  };
+
+  var _method = chainableBehavior.method;
+  chainableBehavior.method = function () {
+    var result = method(_method).apply(this, arguments);
+    return result === undefined ? this : result;
+  };
+};
+
+},{}],26:[function(require,module,exports){
+/*!
+ * Chai - overwriteMethod utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### overwriteMethod (ctx, name, fn)
+ *
+ * Overwites an already existing method and provides
+ * access to previous function. Must return function
+ * to be used for name.
+ *
+ *     utils.overwriteMethod(chai.Assertion.prototype, 'equal', function (_super) {
+ *       return function (str) {
+ *         var obj = utils.flag(this, 'object');
+ *         if (obj instanceof Foo) {
+ *           new chai.Assertion(obj.value).to.equal(str);
+ *         } else {
+ *           _super.apply(this, arguments);
+ *         }
+ *       }
+ *     });
+ *
+ * Can also be accessed directly from `chai.Assertion`.
+ *
+ *     chai.Assertion.overwriteMethod('foo', fn);
+ *
+ * Then can be used as any other assertion.
+ *
+ *     expect(myFoo).to.equal('bar');
+ *
+ * @param {Object} ctx object whose method is to be overwritten
+ * @param {String} name of method to overwrite
+ * @param {Function} method function that returns a function to be used for name
+ * @name overwriteMethod
+ * @api public
+ */
+
+module.exports = function (ctx, name, method) {
+  var _method = ctx[name]
+    , _super = function () { return this; };
+
+  if (_method && 'function' === typeof _method)
+    _super = _method;
+
+  ctx[name] = function () {
+    var result = method(_super).apply(this, arguments);
+    return result === undefined ? this : result;
+  }
+};
+
+},{}],27:[function(require,module,exports){
+/*!
+ * Chai - overwriteProperty utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### overwriteProperty (ctx, name, fn)
+ *
+ * Overwites an already existing property getter and provides
+ * access to previous value. Must return function to use as getter.
+ *
+ *     utils.overwriteProperty(chai.Assertion.prototype, 'ok', function (_super) {
+ *       return function () {
+ *         var obj = utils.flag(this, 'object');
+ *         if (obj instanceof Foo) {
+ *           new chai.Assertion(obj.name).to.equal('bar');
+ *         } else {
+ *           _super.call(this);
+ *         }
+ *       }
+ *     });
+ *
+ *
+ * Can also be accessed directly from `chai.Assertion`.
+ *
+ *     chai.Assertion.overwriteProperty('foo', fn);
+ *
+ * Then can be used as any other assertion.
+ *
+ *     expect(myFoo).to.be.ok;
+ *
+ * @param {Object} ctx object whose property is to be overwritten
+ * @param {String} name of property to overwrite
+ * @param {Function} getter function that returns a getter function to be used for name
+ * @name overwriteProperty
+ * @api public
+ */
+
+module.exports = function (ctx, name, getter) {
+  var _get = Object.getOwnPropertyDescriptor(ctx, name)
+    , _super = function () {};
+
+  if (_get && 'function' === typeof _get.get)
+    _super = _get.get
+
+  Object.defineProperty(ctx, name,
+    { get: function () {
+        var result = getter(_super).call(this);
+        return result === undefined ? this : result;
+      }
+    , configurable: true
+  });
+};
+
+},{}],28:[function(require,module,exports){
+/*!
+ * Chai - test utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Module dependancies
+ */
+
+var flag = require('./flag');
+
+/**
+ * # test(object, expression)
+ *
+ * Test and object for expression.
+ *
+ * @param {Object} object (constructed Assertion)
+ * @param {Arguments} chai.Assertion.prototype.assert arguments
+ */
+
+module.exports = function (obj, args) {
+  var negate = flag(obj, 'negate')
+    , expr = args[0];
+  return negate ? !expr : expr;
+};
+
+},{"./flag":13}],29:[function(require,module,exports){
+/*!
+ * Chai - transferFlags utility
+ * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/**
+ * ### transferFlags(assertion, object, includeAll = true)
+ *
+ * Transfer all the flags for `assertion` to `object`. If
+ * `includeAll` is set to `false`, then the base Chai
+ * assertion flags (namely `object`, `ssfi`, and `message`)
+ * will not be transferred.
+ *
+ *
+ *     var newAssertion = new Assertion();
+ *     utils.transferFlags(assertion, newAssertion);
+ *
+ *     var anotherAsseriton = new Assertion(myObj);
+ *     utils.transferFlags(assertion, anotherAssertion, false);
+ *
+ * @param {Assertion} assertion the assertion to transfer the flags from
+ * @param {Object} object the object to transfer the flags to; usually a new assertion
+ * @param {Boolean} includeAll
+ * @name transferFlags
+ * @api private
+ */
+
+module.exports = function (assertion, object, includeAll) {
+  var flags = assertion.__flags || (assertion.__flags = Object.create(null));
+
+  if (!object.__flags) {
+    object.__flags = Object.create(null);
+  }
+
+  includeAll = arguments.length === 3 ? includeAll : true;
+
+  for (var flag in flags) {
+    if (includeAll ||
+        (flag !== 'object' && flag !== 'ssfi' && flag != 'message')) {
+      object.__flags[flag] = flags[flag];
+    }
+  }
+};
+
+},{}],30:[function(require,module,exports){
+/*!
+ * assertion-error
+ * Copyright(c) 2013 Jake Luer <jake@qualiancy.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Return a function that will copy properties from
+ * one object to another excluding any originally
+ * listed. Returned function will create a new `{}`.
+ *
+ * @param {String} excluded properties ...
+ * @return {Function}
+ */
+
+function exclude () {
+  var excludes = [].slice.call(arguments);
+
+  function excludeProps (res, obj) {
+    Object.keys(obj).forEach(function (key) {
+      if (!~excludes.indexOf(key)) res[key] = obj[key];
+    });
+  }
+
+  return function extendExclude () {
+    var args = [].slice.call(arguments)
+      , i = 0
+      , res = {};
+
+    for (; i < args.length; i++) {
+      excludeProps(res, args[i]);
+    }
+
+    return res;
+  };
+};
+
+/*!
+ * Primary Exports
+ */
+
+module.exports = AssertionError;
+
+/**
+ * ### AssertionError
+ *
+ * An extension of the JavaScript `Error` constructor for
+ * assertion and validation scenarios.
+ *
+ * @param {String} message
+ * @param {Object} properties to include (optional)
+ * @param {callee} start stack function (optional)
+ */
+
+function AssertionError (message, _props, ssf) {
+  var extend = exclude('name', 'message', 'stack', 'constructor', 'toJSON')
+    , props = extend(_props || {});
+
+  // default values
+  this.message = message || 'Unspecified AssertionError';
+  this.showDiff = false;
+
+  // copy from properties
+  for (var key in props) {
+    this[key] = props[key];
+  }
+
+  // capture stack trace
+  ssf = ssf || arguments.callee;
+  if (ssf && Error.captureStackTrace) {
+    Error.captureStackTrace(this, ssf);
+  } else {
+    this.stack = new Error().stack;
+  }
+}
+
+/*!
+ * Inherit from Error.prototype
+ */
+
+AssertionError.prototype = Object.create(Error.prototype);
+
+/*!
+ * Statically set name
+ */
+
+AssertionError.prototype.name = 'AssertionError';
+
+/*!
+ * Ensure correct constructor
+ */
+
+AssertionError.prototype.constructor = AssertionError;
+
+/**
+ * Allow errors to be converted to JSON for static transfer.
+ *
+ * @param {Boolean} include stack (default: `true`)
+ * @return {Object} object that can be `JSON.stringify`
+ */
+
+AssertionError.prototype.toJSON = function (stack) {
+  var extend = exclude('constructor', 'toJSON', 'stack')
+    , props = extend({ name: this.name }, this);
+
+  // include stack if exists and not turned off
+  if (false !== stack && this.stack) {
+    props.stack = this.stack;
+  }
+
+  return props;
+};
+
+},{}],31:[function(require,module,exports){
+module.exports = require('./lib/eql');
+
+},{"./lib/eql":32}],32:[function(require,module,exports){
+/*!
+ * deep-eql
+ * Copyright(c) 2013 Jake Luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Module dependencies
+ */
+
+var type = require('type-detect');
+
+/*!
+ * Buffer.isBuffer browser shim
+ */
+
+var Buffer;
+try { Buffer = require('buffer').Buffer; }
+catch(ex) {
+  Buffer = {};
+  Buffer.isBuffer = function() { return false; }
+}
+
+/*!
+ * Primary Export
+ */
+
+module.exports = deepEqual;
+
+/**
+ * Assert super-strict (egal) equality between
+ * two objects of any type.
+ *
+ * @param {Mixed} a
+ * @param {Mixed} b
+ * @param {Array} memoised (optional)
+ * @return {Boolean} equal match
+ */
+
+function deepEqual(a, b, m) {
+  if (sameValue(a, b)) {
+    return true;
+  } else if ('date' === type(a)) {
+    return dateEqual(a, b);
+  } else if ('regexp' === type(a)) {
+    return regexpEqual(a, b);
+  } else if (Buffer.isBuffer(a)) {
+    return bufferEqual(a, b);
+  } else if ('arguments' === type(a)) {
+    return argumentsEqual(a, b, m);
+  } else if (!typeEqual(a, b)) {
+    return false;
+  } else if (('object' !== type(a) && 'object' !== type(b))
+  && ('array' !== type(a) && 'array' !== type(b))) {
+    return sameValue(a, b);
+  } else {
+    return objectEqual(a, b, m);
+  }
+}
+
+/*!
+ * Strict (egal) equality test. Ensures that NaN always
+ * equals NaN and `-0` does not equal `+0`.
+ *
+ * @param {Mixed} a
+ * @param {Mixed} b
+ * @return {Boolean} equal match
+ */
+
+function sameValue(a, b) {
+  if (a === b) return a !== 0 || 1 / a === 1 / b;
+  return a !== a && b !== b;
+}
+
+/*!
+ * Compare the types of two given objects and
+ * return if they are equal. Note that an Array
+ * has a type of `array` (not `object`) and arguments
+ * have a type of `arguments` (not `array`/`object`).
+ *
+ * @param {Mixed} a
+ * @param {Mixed} b
+ * @return {Boolean} result
+ */
+
+function typeEqual(a, b) {
+  return type(a) === type(b);
+}
+
+/*!
+ * Compare two Date objects by asserting that
+ * the time values are equal using `saveValue`.
+ *
+ * @param {Date} a
+ * @param {Date} b
+ * @return {Boolean} result
+ */
+
+function dateEqual(a, b) {
+  if ('date' !== type(b)) return false;
+  return sameValue(a.getTime(), b.getTime());
+}
+
+/*!
+ * Compare two regular expressions by converting them
+ * to string and checking for `sameValue`.
+ *
+ * @param {RegExp} a
+ * @param {RegExp} b
+ * @return {Boolean} result
+ */
+
+function regexpEqual(a, b) {
+  if ('regexp' !== type(b)) return false;
+  return sameValue(a.toString(), b.toString());
+}
+
+/*!
+ * Assert deep equality of two `arguments` objects.
+ * Unfortunately, these must be sliced to arrays
+ * prior to test to ensure no bad behavior.
+ *
+ * @param {Arguments} a
+ * @param {Arguments} b
+ * @param {Array} memoize (optional)
+ * @return {Boolean} result
+ */
+
+function argumentsEqual(a, b, m) {
+  if ('arguments' !== type(b)) return false;
+  a = [].slice.call(a);
+  b = [].slice.call(b);
+  return deepEqual(a, b, m);
+}
+
+/*!
+ * Get enumerable properties of a given object.
+ *
+ * @param {Object} a
+ * @return {Array} property names
+ */
+
+function enumerable(a) {
+  var res = [];
+  for (var key in a) res.push(key);
+  return res;
+}
+
+/*!
+ * Simple equality for flat iterable objects
+ * such as Arrays or Node.js buffers.
+ *
+ * @param {Iterable} a
+ * @param {Iterable} b
+ * @return {Boolean} result
+ */
+
+function iterableEqual(a, b) {
+  if (a.length !==  b.length) return false;
+
+  var i = 0;
+  var match = true;
+
+  for (; i < a.length; i++) {
+    if (a[i] !== b[i]) {
+      match = false;
+      break;
+    }
+  }
+
+  return match;
+}
+
+/*!
+ * Extension to `iterableEqual` specifically
+ * for Node.js Buffers.
+ *
+ * @param {Buffer} a
+ * @param {Mixed} b
+ * @return {Boolean} result
+ */
+
+function bufferEqual(a, b) {
+  if (!Buffer.isBuffer(b)) return false;
+  return iterableEqual(a, b);
+}
+
+/*!
+ * Block for `objectEqual` ensuring non-existing
+ * values don't get in.
+ *
+ * @param {Mixed} object
+ * @return {Boolean} result
+ */
+
+function isValue(a) {
+  return a !== null && a !== undefined;
+}
+
+/*!
+ * Recursively check the equality of two objects.
+ * Once basic sameness has been established it will
+ * defer to `deepEqual` for each enumerable key
+ * in the object.
+ *
+ * @param {Mixed} a
+ * @param {Mixed} b
+ * @return {Boolean} result
+ */
+
+function objectEqual(a, b, m) {
+  if (!isValue(a) || !isValue(b)) {
+    return false;
+  }
+
+  if (a.prototype !== b.prototype) {
+    return false;
+  }
+
+  var i;
+  if (m) {
+    for (i = 0; i < m.length; i++) {
+      if ((m[i][0] === a && m[i][1] === b)
+      ||  (m[i][0] === b && m[i][1] === a)) {
+        return true;
+      }
+    }
+  } else {
+    m = [];
+  }
+
+  try {
+    var ka = enumerable(a);
+    var kb = enumerable(b);
+  } catch (ex) {
+    return false;
+  }
+
+  ka.sort();
+  kb.sort();
+
+  if (!iterableEqual(ka, kb)) {
+    return false;
+  }
+
+  m.push([ a, b ]);
+
+  var key;
+  for (i = ka.length - 1; i >= 0; i--) {
+    key = ka[i];
+    if (!deepEqual(a[key], b[key], m)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+},{"buffer":undefined,"type-detect":33}],33:[function(require,module,exports){
+module.exports = require('./lib/type');
+
+},{"./lib/type":34}],34:[function(require,module,exports){
+/*!
+ * type-detect
+ * Copyright(c) 2013 jake luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Primary Exports
+ */
+
+var exports = module.exports = getType;
+
+/*!
+ * Detectable javascript natives
+ */
+
+var natives = {
+    '[object Array]': 'array'
+  , '[object RegExp]': 'regexp'
+  , '[object Function]': 'function'
+  , '[object Arguments]': 'arguments'
+  , '[object Date]': 'date'
+};
+
+/**
+ * ### typeOf (obj)
+ *
+ * Use several different techniques to determine
+ * the type of object being tested.
+ *
+ *
+ * @param {Mixed} object
+ * @return {String} object type
+ * @api public
+ */
+
+function getType (obj) {
+  var str = Object.prototype.toString.call(obj);
+  if (natives[str]) return natives[str];
+  if (obj === null) return 'null';
+  if (obj === undefined) return 'undefined';
+  if (obj === Object(obj)) return 'object';
+  return typeof obj;
+}
+
+exports.Library = Library;
+
+/**
+ * ### Library
+ *
+ * Create a repository for custom type detection.
+ *
+ * ```js
+ * var lib = new type.Library;
+ * ```
+ *
+ */
+
+function Library () {
+  this.tests = {};
+}
+
+/**
+ * #### .of (obj)
+ *
+ * Expose replacement `typeof` detection to the library.
+ *
+ * ```js
+ * if ('string' === lib.of('hello world')) {
+ *   // ...
+ * }
+ * ```
+ *
+ * @param {Mixed} object to test
+ * @return {String} type
+ */
+
+Library.prototype.of = getType;
+
+/**
+ * #### .define (type, test)
+ *
+ * Add a test to for the `.test()` assertion.
+ *
+ * Can be defined as a regular expression:
+ *
+ * ```js
+ * lib.define('int', /^[0-9]+$/);
+ * ```
+ *
+ * ... or as a function:
+ *
+ * ```js
+ * lib.define('bln', function (obj) {
+ *   if ('boolean' === lib.of(obj)) return true;
+ *   var blns = [ 'yes', 'no', 'true', 'false', 1, 0 ];
+ *   if ('string' === lib.of(obj)) obj = obj.toLowerCase();
+ *   return !! ~blns.indexOf(obj);
+ * });
+ * ```
+ *
+ * @param {String} type
+ * @param {RegExp|Function} test
+ * @api public
+ */
+
+Library.prototype.define = function (type, test) {
+  if (arguments.length === 1) return this.tests[type];
+  this.tests[type] = test;
+  return this;
+};
+
+/**
+ * #### .test (obj, test)
+ *
+ * Assert that an object is of type. Will first
+ * check natives, and if that does not pass it will
+ * use the user defined custom tests.
+ *
+ * ```js
+ * assert(lib.test('1', 'int'));
+ * assert(lib.test('yes', 'bln'));
+ * ```
+ *
+ * @param {Mixed} object
+ * @param {String} type
+ * @return {Boolean} result
+ * @api public
+ */
+
+Library.prototype.test = function (obj, type) {
+  if (type === getType(obj)) return true;
+  var test = this.tests[type];
+
+  if (test && 'regexp' === getType(test)) {
+    return test.test(obj);
+  } else if (test && 'function' === getType(test)) {
+    return test(obj);
+  } else {
+    throw new ReferenceError('Type test "' + type + '" not defined or invalid.');
+  }
+};
+
+},{}],35:[function(require,module,exports){
+arguments[4][33][0].apply(exports,arguments)
+},{"./lib/type":36,"dup":33}],36:[function(require,module,exports){
+/*!
+ * type-detect
+ * Copyright(c) 2013 jake luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+
+/*!
+ * Primary Exports
+ */
+
+var exports = module.exports = getType;
+
+/**
+ * ### typeOf (obj)
+ *
+ * Use several different techniques to determine
+ * the type of object being tested.
+ *
+ *
+ * @param {Mixed} object
+ * @return {String} object type
+ * @api public
+ */
+var objectTypeRegexp = /^\[object (.*)\]$/;
+
+function getType(obj) {
+  var type = Object.prototype.toString.call(obj).match(objectTypeRegexp)[1].toLowerCase();
+  // Let "new String('')" return 'object'
+  if (typeof Promise === 'function' && obj instanceof Promise) return 'promise';
+  // PhantomJS has type "DOMWindow" for null
+  if (obj === null) return 'null';
+  // PhantomJS has type "DOMWindow" for undefined
+  if (obj === undefined) return 'undefined';
+  return type;
+}
+
+exports.Library = Library;
+
+/**
+ * ### Library
+ *
+ * Create a repository for custom type detection.
+ *
+ * ```js
+ * var lib = new type.Library;
+ * ```
+ *
+ */
+
+function Library() {
+  if (!(this instanceof Library)) return new Library();
+  this.tests = {};
+}
+
+/**
+ * #### .of (obj)
+ *
+ * Expose replacement `typeof` detection to the library.
+ *
+ * ```js
+ * if ('string' === lib.of('hello world')) {
+ *   // ...
+ * }
+ * ```
+ *
+ * @param {Mixed} object to test
+ * @return {String} type
+ */
+
+Library.prototype.of = getType;
+
+/**
+ * #### .define (type, test)
+ *
+ * Add a test to for the `.test()` assertion.
+ *
+ * Can be defined as a regular expression:
+ *
+ * ```js
+ * lib.define('int', /^[0-9]+$/);
+ * ```
+ *
+ * ... or as a function:
+ *
+ * ```js
+ * lib.define('bln', function (obj) {
+ *   if ('boolean' === lib.of(obj)) return true;
+ *   var blns = [ 'yes', 'no', 'true', 'false', 1, 0 ];
+ *   if ('string' === lib.of(obj)) obj = obj.toLowerCase();
+ *   return !! ~blns.indexOf(obj);
+ * });
+ * ```
+ *
+ * @param {String} type
+ * @param {RegExp|Function} test
+ * @api public
+ */
+
+Library.prototype.define = function(type, test) {
+  if (arguments.length === 1) return this.tests[type];
+  this.tests[type] = test;
+  return this;
+};
+
+/**
+ * #### .test (obj, test)
+ *
+ * Assert that an object is of type. Will first
+ * check natives, and if that does not pass it will
+ * use the user defined custom tests.
+ *
+ * ```js
+ * assert(lib.test('1', 'int'));
+ * assert(lib.test('yes', 'bln'));
+ * ```
+ *
+ * @param {Mixed} object
+ * @param {String} type
+ * @return {Boolean} result
+ * @api public
+ */
+
+Library.prototype.test = function(obj, type) {
+  if (type === getType(obj)) return true;
+  var test = this.tests[type];
+
+  if (test && 'regexp' === getType(test)) {
+    return test.test(obj);
+  } else if (test && 'function' === getType(test)) {
+    return test(obj);
+  } else {
+    throw new ReferenceError('Type test "' + type + '" not defined or invalid.');
+  }
+};
+
+},{}]},{},[1])(1)
+});