(function() {

  module('Objects');

  test('keys', function() {
    deepEqual(_.keys({one : 1, two : 2}), ['one', 'two'], 'can extract the keys from an object');
    // the test above is not safe because it relies on for-in enumeration order
    var a = []; a[1] = 0;
    deepEqual(_.keys(a), ['1'], 'is not fooled by sparse arrays; see issue #95');
    deepEqual(_.keys(null), []);
    deepEqual(_.keys(void 0), []);
    deepEqual(_.keys(1), []);
    deepEqual(_.keys('a'), []);
    deepEqual(_.keys(true), []);
  });

  test('values', function() {
    deepEqual(_.values({one: 1, two: 2}), [1, 2], 'can extract the values from an object');
    deepEqual(_.values({one: 1, two: 2, length: 3}), [1, 2, 3], '... even when one of them is "length"');
  });

  test('pairs', function() {
    deepEqual(_.pairs({one: 1, two: 2}), [['one', 1], ['two', 2]], 'can convert an object into pairs');
    deepEqual(_.pairs({one: 1, two: 2, length: 3}), [['one', 1], ['two', 2], ['length', 3]], '... even when one of them is "length"');
  });

  test('invert', function() {
    var obj = {first: 'Moe', second: 'Larry', third: 'Curly'};
    deepEqual(_.keys(_.invert(obj)), ['Moe', 'Larry', 'Curly'], 'can invert an object');
    ok(_.isEqual(_.invert(_.invert(obj)), obj), 'two inverts gets you back where you started');

    var obj = {length: 3};
    ok(_.invert(obj)['3'] == 'length', 'can invert an object with "length"')
  });

  test('functions', function() {
    var obj = {a : 'dash', b : _.map, c : (/yo/), d : _.reduce};
    ok(_.isEqual(['b', 'd'], _.functions(obj)), 'can grab the function names of any passed-in object');

    var Animal = function(){};
    Animal.prototype.run = function(){};
    deepEqual(_.functions(new Animal), ['run'], 'also looks up functions on the prototype');
  });

  test('extend', function() {
    var result;
    equal(_.extend({}, {a:'b'}).a, 'b', 'can extend an object with the attributes of another');
    equal(_.extend({a:'x'}, {a:'b'}).a, 'b', 'properties in source override destination');
    equal(_.extend({x:'x'}, {a:'b'}).x, 'x', "properties not in source don't get overriden");
    result = _.extend({x:'x'}, {a:'a'}, {b:'b'});
    ok(_.isEqual(result, {x:'x', a:'a', b:'b'}), 'can extend from multiple source objects');
    result = _.extend({x:'x'}, {a:'a', x:2}, {a:'b'});
    ok(_.isEqual(result, {x:2, a:'b'}), 'extending from multiple source objects last property trumps');
    result = _.extend({}, {a: void 0, b: null});
    deepEqual(_.keys(result), ['a', 'b'], 'extend copies undefined values');

    try {
      result = {};
      _.extend(result, null, undefined, {a:1});
    } catch(ex) {}

    equal(result.a, 1, 'should not error on `null` or `undefined` sources');
  });

  test('pick', function() {
    var result;
    result = _.pick({a: 1, b: 2, c: 3}, 'a', 'c');
    deepEqual(result, {a: 1, c: 3}, 'can restrict properties to those named');
    result = _.pick({a: 1, b: 2, c: 3}, ['b', 'c']);
    deepEqual(result, {b: 2, c: 3}, 'can restrict properties to those named in an array');
    result = _.pick({a: 1, b: 2, c: 3}, ['a'], 'b');
    deepEqual(result, {a: 1, b: 2}, 'can restrict properties to those named in mixed args');
    result = _.pick(['a', 'b'], 1);
    deepEqual(result, {1: 'b'}, 'can pick numeric properties');

    var data = {a: 1, b: 2, c: 3};
    var callback = function(value, key, object) {
      strictEqual(key, {1: 'a', 2: 'b', 3: 'c'}[value]);
      strictEqual(object, data);
      return value !== this.value;
    };
    result = _.pick(data, callback, {value: 2});
    deepEqual(result, {a: 1, c: 3}, 'can accept a predicate and context');

    var Obj = function(){};
    Obj.prototype = {a: 1, b: 2, c: 3};
    deepEqual(_.pick(new Obj, 'a', 'c'), {a: 1, c: 3}, 'include prototype props');
  });

  test('omit', function() {
    var result;
    result = _.omit({a: 1, b: 2, c: 3}, 'b');
    deepEqual(result, {a: 1, c: 3}, 'can omit a single named property');
    result = _.omit({a: 1, b: 2, c: 3}, 'a', 'c');
    deepEqual(result, {b: 2}, 'can omit several named properties');
    result = _.omit({a: 1, b: 2, c: 3}, ['b', 'c']);
    deepEqual(result, {a: 1}, 'can omit properties named in an array');
    result = _.omit(['a', 'b'], 0);
    deepEqual(result, {1: 'b'}, 'can omit numeric properties');

    var data = {a: 1, b: 2, c: 3};
    var callback = function(value, key, object) {
      strictEqual(key, {1: 'a', 2: 'b', 3: 'c'}[value]);
      strictEqual(object, data);
      return value !== this.value;
    };
    result = _.omit(data, callback, {value: 2});
    deepEqual(result, {b: 2}, 'can accept a predicate');

    var Obj = function(){};
    Obj.prototype = {a: 1, b: 2, c: 3};
    deepEqual(_.omit(new Obj, 'b'), {a: 1, c: 3}, 'include prototype props');
  });

  test('defaults', function() {
    var result;
    var options = {zero: 0, one: 1, empty: '', nan: NaN, nothing: null};

    _.defaults(options, {zero: 1, one: 10, twenty: 20, nothing: 'str'});
    equal(options.zero, 0, 'value exists');
    equal(options.one, 1, 'value exists');
    equal(options.twenty, 20, 'default applied');
    equal(options.nothing, null, "null isn't overridden");

    _.defaults(options, {empty: 'full'}, {nan: 'nan'}, {word: 'word'}, {word: 'dog'});
    equal(options.empty, '', 'value exists');
    ok(_.isNaN(options.nan), "NaN isn't overridden");
    equal(options.word, 'word', 'new value is added, first one wins');

    try {
      options = {};
      _.defaults(options, null, undefined, {a:1});
    } catch(ex) {}

    equal(options.a, 1, 'should not error on `null` or `undefined` sources');
  });

  test('clone', function() {
    var moe = {name : 'moe', lucky : [13, 27, 34]};
    var clone = _.clone(moe);
    equal(clone.name, 'moe', 'the clone as the attributes of the original');

    clone.name = 'curly';
    ok(clone.name == 'curly' && moe.name == 'moe', 'clones can change shallow attributes without affecting the original');

    clone.lucky.push(101);
    equal(_.last(moe.lucky), 101, 'changes to deep attributes are shared with the original');

    equal(_.clone(undefined), void 0, 'non objects should not be changed by clone');
    equal(_.clone(1), 1, 'non objects should not be changed by clone');
    equal(_.clone(null), null, 'non objects should not be changed by clone');
  });

  test('isEqual', function() {
    function First() {
      this.value = 1;
    }
    First.prototype.value = 1;
    function Second() {
      this.value = 1;
    }
    Second.prototype.value = 2;

    // Basic equality and identity comparisons.
    ok(_.isEqual(null, null), '`null` is equal to `null`');
    ok(_.isEqual(), '`undefined` is equal to `undefined`');

    ok(!_.isEqual(0, -0), '`0` is not equal to `-0`');
    ok(!_.isEqual(-0, 0), 'Commutative equality is implemented for `0` and `-0`');
    ok(!_.isEqual(null, undefined), '`null` is not equal to `undefined`');
    ok(!_.isEqual(undefined, null), 'Commutative equality is implemented for `null` and `undefined`');

    // String object and primitive comparisons.
    ok(_.isEqual('Curly', 'Curly'), 'Identical string primitives are equal');
    ok(_.isEqual(new String('Curly'), new String('Curly')), 'String objects with identical primitive values are equal');
    ok(_.isEqual(new String('Curly'), 'Curly'), 'String primitives and their corresponding object wrappers are equal');
    ok(_.isEqual('Curly', new String('Curly')), 'Commutative equality is implemented for string objects and primitives');

    ok(!_.isEqual('Curly', 'Larry'), 'String primitives with different values are not equal');
    ok(!_.isEqual(new String('Curly'), new String('Larry')), 'String objects with different primitive values are not equal');
    ok(!_.isEqual(new String('Curly'), {toString: function(){ return 'Curly'; }}), 'String objects and objects with a custom `toString` method are not equal');

    // Number object and primitive comparisons.
    ok(_.isEqual(75, 75), 'Identical number primitives are equal');
    ok(_.isEqual(new Number(75), new Number(75)), 'Number objects with identical primitive values are equal');
    ok(_.isEqual(75, new Number(75)), 'Number primitives and their corresponding object wrappers are equal');
    ok(_.isEqual(new Number(75), 75), 'Commutative equality is implemented for number objects and primitives');
    ok(!_.isEqual(new Number(0), -0), '`new Number(0)` and `-0` are not equal');
    ok(!_.isEqual(0, new Number(-0)), 'Commutative equality is implemented for `new Number(0)` and `-0`');

    ok(!_.isEqual(new Number(75), new Number(63)), 'Number objects with different primitive values are not equal');
    ok(!_.isEqual(new Number(63), {valueOf: function(){ return 63; }}), 'Number objects and objects with a `valueOf` method are not equal');

    // Comparisons involving `NaN`.
    ok(_.isEqual(NaN, NaN), '`NaN` is equal to `NaN`');
    ok(!_.isEqual(61, NaN), 'A number primitive is not equal to `NaN`');
    ok(!_.isEqual(new Number(79), NaN), 'A number object is not equal to `NaN`');
    ok(!_.isEqual(Infinity, NaN), '`Infinity` is not equal to `NaN`');

    // Boolean object and primitive comparisons.
    ok(_.isEqual(true, true), 'Identical boolean primitives are equal');
    ok(_.isEqual(new Boolean, new Boolean), 'Boolean objects with identical primitive values are equal');
    ok(_.isEqual(true, new Boolean(true)), 'Boolean primitives and their corresponding object wrappers are equal');
    ok(_.isEqual(new Boolean(true), true), 'Commutative equality is implemented for booleans');
    ok(!_.isEqual(new Boolean(true), new Boolean), 'Boolean objects with different primitive values are not equal');

    // Common type coercions.
    ok(!_.isEqual(new Boolean(false), true), '`new Boolean(false)` is not equal to `true`');
    ok(!_.isEqual('75', 75), 'String and number primitives with like values are not equal');
    ok(!_.isEqual(new Number(63), new String(63)), 'String and number objects with like values are not equal');
    ok(!_.isEqual(75, '75'), 'Commutative equality is implemented for like string and number values');
    ok(!_.isEqual(0, ''), 'Number and string primitives with like values are not equal');
    ok(!_.isEqual(1, true), 'Number and boolean primitives with like values are not equal');
    ok(!_.isEqual(new Boolean(false), new Number(0)), 'Boolean and number objects with like values are not equal');
    ok(!_.isEqual(false, new String('')), 'Boolean primitives and string objects with like values are not equal');
    ok(!_.isEqual(12564504e5, new Date(2009, 9, 25)), 'Dates and their corresponding numeric primitive values are not equal');

    // Dates.
    ok(_.isEqual(new Date(2009, 9, 25), new Date(2009, 9, 25)), 'Date objects referencing identical times are equal');
    ok(!_.isEqual(new Date(2009, 9, 25), new Date(2009, 11, 13)), 'Date objects referencing different times are not equal');
    ok(!_.isEqual(new Date(2009, 11, 13), {
      getTime: function(){
        return 12606876e5;
      }
    }), 'Date objects and objects with a `getTime` method are not equal');
    ok(!_.isEqual(new Date('Curly'), new Date('Curly')), 'Invalid dates are not equal');

    // Functions.
    ok(!_.isEqual(First, Second), 'Different functions with identical bodies and source code representations are not equal');

    // RegExps.
    ok(_.isEqual(/(?:)/gim, /(?:)/gim), 'RegExps with equivalent patterns and flags are equal');
    ok(_.isEqual(/(?:)/gi, /(?:)/ig), 'Flag order is not significant');
    ok(!_.isEqual(/(?:)/g, /(?:)/gi), 'RegExps with equivalent patterns and different flags are not equal');
    ok(!_.isEqual(/Moe/gim, /Curly/gim), 'RegExps with different patterns and equivalent flags are not equal');
    ok(!_.isEqual(/(?:)/gi, /(?:)/g), 'Commutative equality is implemented for RegExps');
    ok(!_.isEqual(/Curly/g, {source: 'Larry', global: true, ignoreCase: false, multiline: false}), 'RegExps and RegExp-like objects are not equal');

    // Empty arrays, array-like objects, and object literals.
    ok(_.isEqual({}, {}), 'Empty object literals are equal');
    ok(_.isEqual([], []), 'Empty array literals are equal');
    ok(_.isEqual([{}], [{}]), 'Empty nested arrays and objects are equal');
    ok(!_.isEqual({length: 0}, []), 'Array-like objects and arrays are not equal.');
    ok(!_.isEqual([], {length: 0}), 'Commutative equality is implemented for array-like objects');

    ok(!_.isEqual({}, []), 'Object literals and array literals are not equal');
    ok(!_.isEqual([], {}), 'Commutative equality is implemented for objects and arrays');

    // Arrays with primitive and object values.
    ok(_.isEqual([1, 'Larry', true], [1, 'Larry', true]), 'Arrays containing identical primitives are equal');
    ok(_.isEqual([(/Moe/g), new Date(2009, 9, 25)], [(/Moe/g), new Date(2009, 9, 25)]), 'Arrays containing equivalent elements are equal');

    // Multi-dimensional arrays.
    var a = [new Number(47), false, 'Larry', /Moe/, new Date(2009, 11, 13), ['running', 'biking', new String('programming')], {a: 47}];
    var b = [new Number(47), false, 'Larry', /Moe/, new Date(2009, 11, 13), ['running', 'biking', new String('programming')], {a: 47}];
    ok(_.isEqual(a, b), 'Arrays containing nested arrays and objects are recursively compared');

    // Overwrite the methods defined in ES 5.1 section 15.4.4.
    a.forEach = a.map = a.filter = a.every = a.indexOf = a.lastIndexOf = a.some = a.reduce = a.reduceRight = null;
    b.join = b.pop = b.reverse = b.shift = b.slice = b.splice = b.concat = b.sort = b.unshift = null;

    // Array elements and properties.
    ok(_.isEqual(a, b), 'Arrays containing equivalent elements and different non-numeric properties are equal');
    a.push('White Rocks');
    ok(!_.isEqual(a, b), 'Arrays of different lengths are not equal');
    a.push('East Boulder');
    b.push('Gunbarrel Ranch', 'Teller Farm');
    ok(!_.isEqual(a, b), 'Arrays of identical lengths containing different elements are not equal');

    // Sparse arrays.
    ok(_.isEqual(Array(3), Array(3)), 'Sparse arrays of identical lengths are equal');
    ok(!_.isEqual(Array(3), Array(6)), 'Sparse arrays of different lengths are not equal when both are empty');

    // Simple objects.
    ok(_.isEqual({a: 'Curly', b: 1, c: true}, {a: 'Curly', b: 1, c: true}), 'Objects containing identical primitives are equal');
    ok(_.isEqual({a: /Curly/g, b: new Date(2009, 11, 13)}, {a: /Curly/g, b: new Date(2009, 11, 13)}), 'Objects containing equivalent members are equal');
    ok(!_.isEqual({a: 63, b: 75}, {a: 61, b: 55}), 'Objects of identical sizes with different values are not equal');
    ok(!_.isEqual({a: 63, b: 75}, {a: 61, c: 55}), 'Objects of identical sizes with different property names are not equal');
    ok(!_.isEqual({a: 1, b: 2}, {a: 1}), 'Objects of different sizes are not equal');
    ok(!_.isEqual({a: 1}, {a: 1, b: 2}), 'Commutative equality is implemented for objects');
    ok(!_.isEqual({x: 1, y: undefined}, {x: 1, z: 2}), 'Objects with identical keys and different values are not equivalent');

    // `A` contains nested objects and arrays.
    a = {
      name: new String('Moe Howard'),
      age: new Number(77),
      stooge: true,
      hobbies: ['acting'],
      film: {
        name: 'Sing a Song of Six Pants',
        release: new Date(1947, 9, 30),
        stars: [new String('Larry Fine'), 'Shemp Howard'],
        minutes: new Number(16),
        seconds: 54
      }
    };

    // `B` contains equivalent nested objects and arrays.
    b = {
      name: new String('Moe Howard'),
      age: new Number(77),
      stooge: true,
      hobbies: ['acting'],
      film: {
        name: 'Sing a Song of Six Pants',
        release: new Date(1947, 9, 30),
        stars: [new String('Larry Fine'), 'Shemp Howard'],
        minutes: new Number(16),
        seconds: 54
      }
    };
    ok(_.isEqual(a, b), 'Objects with nested equivalent members are recursively compared');

    // Instances.
    ok(_.isEqual(new First, new First), 'Object instances are equal');
    ok(!_.isEqual(new First, new Second), 'Objects with different constructors and identical own properties are not equal');
    ok(!_.isEqual({value: 1}, new First), 'Object instances and objects sharing equivalent properties are not equal');
    ok(!_.isEqual({value: 2}, new Second), 'The prototype chain of objects should not be examined');

    // Circular Arrays.
    (a = []).push(a);
    (b = []).push(b);
    ok(_.isEqual(a, b), 'Arrays containing circular references are equal');
    a.push(new String('Larry'));
    b.push(new String('Larry'));
    ok(_.isEqual(a, b), 'Arrays containing circular references and equivalent properties are equal');
    a.push('Shemp');
    b.push('Curly');
    ok(!_.isEqual(a, b), 'Arrays containing circular references and different properties are not equal');

    // More circular arrays #767.
    a = ['everything is checked but', 'this', 'is not'];
    a[1] = a;
    b = ['everything is checked but', ['this', 'array'], 'is not'];
    ok(!_.isEqual(a, b), 'Comparison of circular references with non-circular references are not equal');

    // Circular Objects.
    a = {abc: null};
    b = {abc: null};
    a.abc = a;
    b.abc = b;
    ok(_.isEqual(a, b), 'Objects containing circular references are equal');
    a.def = 75;
    b.def = 75;
    ok(_.isEqual(a, b), 'Objects containing circular references and equivalent properties are equal');
    a.def = new Number(75);
    b.def = new Number(63);
    ok(!_.isEqual(a, b), 'Objects containing circular references and different properties are not equal');

    // More circular objects #767.
    a = {everything: 'is checked', but: 'this', is: 'not'};
    a.but = a;
    b = {everything: 'is checked', but: {that:'object'}, is: 'not'};
    ok(!_.isEqual(a, b), 'Comparison of circular references with non-circular object references are not equal');

    // Cyclic Structures.
    a = [{abc: null}];
    b = [{abc: null}];
    (a[0].abc = a).push(a);
    (b[0].abc = b).push(b);
    ok(_.isEqual(a, b), 'Cyclic structures are equal');
    a[0].def = 'Larry';
    b[0].def = 'Larry';
    ok(_.isEqual(a, b), 'Cyclic structures containing equivalent properties are equal');
    a[0].def = new String('Larry');
    b[0].def = new String('Curly');
    ok(!_.isEqual(a, b), 'Cyclic structures containing different properties are not equal');

    // Complex Circular References.
    a = {foo: {b: {foo: {c: {foo: null}}}}};
    b = {foo: {b: {foo: {c: {foo: null}}}}};
    a.foo.b.foo.c.foo = a;
    b.foo.b.foo.c.foo = b;
    ok(_.isEqual(a, b), 'Cyclic structures with nested and identically-named properties are equal');

    // Chaining.
    ok(!_.isEqual(_({x: 1, y: undefined}).chain(), _({x: 1, z: 2}).chain()), 'Chained objects containing different values are not equal');

    a = _({x: 1, y: 2}).chain();
    b = _({x: 1, y: 2}).chain();
    equal(_.isEqual(a.isEqual(b), _(true)), true, '`isEqual` can be chained');

    // Objects from another frame.
    ok(_.isEqual({}, iObject));

    // Objects without a `constructor` property
    if (Object.create) {
        a = Object.create(null, {x: {value: 1, enumerable: true}});
        b = {x: 1};
        ok(_.isEqual(a, b));
    }

    function Foo() { this.a = 1; }
    Foo.prototype.constructor = null;

    var other = { 'a': 1 };
    strictEqual(_.isEqual(new Foo, other), false);
  });

  test('isEmpty', function() {
    ok(!_([1]).isEmpty(), '[1] is not empty');
    ok(_.isEmpty([]), '[] is empty');
    ok(!_.isEmpty({one : 1}), '{one : 1} is not empty');
    ok(_.isEmpty({}), '{} is empty');
    ok(_.isEmpty(new RegExp('')), 'objects with prototype properties are empty');
    ok(_.isEmpty(null), 'null is empty');
    ok(_.isEmpty(), 'undefined is empty');
    ok(_.isEmpty(''), 'the empty string is empty');
    ok(!_.isEmpty('moe'), 'but other strings are not');

    var obj = {one : 1};
    delete obj.one;
    ok(_.isEmpty(obj), 'deleting all the keys from an object empties it');

    var args = function(){ return arguments; };
    ok(_.isEmpty(args()), 'empty arguments object is empty');
    ok(!_.isEmpty(args('')), 'non-empty arguments object is not empty');
  });

  // Setup remote variables for iFrame tests.
  var iframe = document.createElement('iframe');
  iframe.frameBorder = iframe.height = iframe.width = 0
  document.body.appendChild(iframe);
  var iDoc = (iDoc = iframe.contentDocument || iframe.contentWindow).document || iDoc;
  iDoc.write(
    '<script>\
      parent.iElement   = document.createElement("div");\
      parent.iArguments = (function(){ return arguments; })(1, 2, 3);\
      parent.iArray     = [1, 2, 3];\
      parent.iString    = new String("hello");\
      parent.iNumber    = new Number(100);\
      parent.iFunction  = (function(){});\
      parent.iDate      = new Date();\
      parent.iRegExp    = /hi/;\
      parent.iNaN       = NaN;\
      parent.iNull      = null;\
      parent.iBoolean   = new Boolean(false);\
      parent.iUndefined = undefined;\
      parent.iObject     = {};\
    </script>'
  );
  iDoc.close();

  test('isElement', function() {
    ok(!_.isElement('div'), 'strings are not dom elements');
    ok(_.isElement(document.body), 'the body tag is a DOM element');
    ok(_.isElement(iElement), 'even from another frame');
  });

  test('isArguments', function() {
    var args = (function(){ return arguments; })(1, 2, 3);
    ok(!_.isArguments('string'), 'a string is not an arguments object');
    ok(!_.isArguments(_.isArguments), 'a function is not an arguments object');
    ok(_.isArguments(args), 'but the arguments object is an arguments object');
    ok(!_.isArguments(_.toArray(args)), 'but not when it\'s converted into an array');
    ok(!_.isArguments([1,2,3]), 'and not vanilla arrays.');
    ok(_.isArguments(iArguments), 'even from another frame');
  });

  test('isObject', function() {
    ok(_.isObject(arguments), 'the arguments object is object');
    ok(_.isObject([1, 2, 3]), 'and arrays');
    ok(_.isObject(document.body), 'and DOM element');
    ok(_.isObject(iElement), 'even from another frame');
    ok(_.isObject(function () {}), 'and functions');
    ok(_.isObject(iFunction), 'even from another frame');
    ok(!_.isObject(null), 'but not null');
    ok(!_.isObject(undefined), 'and not undefined');
    ok(!_.isObject('string'), 'and not string');
    ok(!_.isObject(12), 'and not number');
    ok(!_.isObject(true), 'and not boolean');
    ok(_.isObject(new String('string')), 'but new String()');
  });

  test('isArray', function() {
    ok(!_.isArray(undefined), 'undefined vars are not arrays');
    ok(!_.isArray(arguments), 'the arguments object is not an array');
    ok(_.isArray([1, 2, 3]), 'but arrays are');
    ok(_.isArray(iArray), 'even from another frame');
  });

  test('isString', function() {
    var obj = new String('I am a string object');
    ok(!_.isString(document.body), 'the document body is not a string');
    ok(_.isString([1, 2, 3].join(', ')), 'but strings are');
    ok(_.isString(iString), 'even from another frame');
    ok(_.isString('I am a string literal'), 'string literals are');
    ok(_.isString(obj), 'so are String objects');
  });

  test('isNumber', function() {
    ok(!_.isNumber('string'), 'a string is not a number');
    ok(!_.isNumber(arguments), 'the arguments object is not a number');
    ok(!_.isNumber(undefined), 'undefined is not a number');
    ok(_.isNumber(3 * 4 - 7 / 10), 'but numbers are');
    ok(_.isNumber(NaN), 'NaN *is* a number');
    ok(_.isNumber(Infinity), 'Infinity is a number');
    ok(_.isNumber(iNumber), 'even from another frame');
    ok(!_.isNumber('1'), 'numeric strings are not numbers');
  });

  test('isBoolean', function() {
    ok(!_.isBoolean(2), 'a number is not a boolean');
    ok(!_.isBoolean('string'), 'a string is not a boolean');
    ok(!_.isBoolean('false'), 'the string "false" is not a boolean');
    ok(!_.isBoolean('true'), 'the string "true" is not a boolean');
    ok(!_.isBoolean(arguments), 'the arguments object is not a boolean');
    ok(!_.isBoolean(undefined), 'undefined is not a boolean');
    ok(!_.isBoolean(NaN), 'NaN is not a boolean');
    ok(!_.isBoolean(null), 'null is not a boolean');
    ok(_.isBoolean(true), 'but true is');
    ok(_.isBoolean(false), 'and so is false');
    ok(_.isBoolean(iBoolean), 'even from another frame');
  });

  test('isFunction', function() {
    ok(!_.isFunction(undefined), 'undefined vars are not functions');
    ok(!_.isFunction([1, 2, 3]), 'arrays are not functions');
    ok(!_.isFunction('moe'), 'strings are not functions');
    ok(_.isFunction(_.isFunction), 'but functions are');
    ok(_.isFunction(iFunction), 'even from another frame');
    ok(_.isFunction(function(){}), 'even anonymous ones');
  });

  test('isDate', function() {
    ok(!_.isDate(100), 'numbers are not dates');
    ok(!_.isDate({}), 'objects are not dates');
    ok(_.isDate(new Date()), 'but dates are');
    ok(_.isDate(iDate), 'even from another frame');
  });

  test('isRegExp', function() {
    ok(!_.isRegExp(_.identity), 'functions are not RegExps');
    ok(_.isRegExp(/identity/), 'but RegExps are');
    ok(_.isRegExp(iRegExp), 'even from another frame');
  });

  test('isFinite', function() {
    ok(!_.isFinite(undefined), 'undefined is not finite');
    ok(!_.isFinite(null), 'null is not finite');
    ok(!_.isFinite(NaN), 'NaN is not finite');
    ok(!_.isFinite(Infinity), 'Infinity is not finite');
    ok(!_.isFinite(-Infinity), '-Infinity is not finite');
    ok(_.isFinite('12'), 'Numeric strings are numbers');
    ok(!_.isFinite('1a'), 'Non numeric strings are not numbers');
    ok(!_.isFinite(''), 'Empty strings are not numbers');
    var obj = new Number(5);
    ok(_.isFinite(obj), 'Number instances can be finite');
    ok(_.isFinite(0), '0 is finite');
    ok(_.isFinite(123), 'Ints are finite');
    ok(_.isFinite(-12.44), 'Floats are finite');
  });

  test('isNaN', function() {
    ok(!_.isNaN(undefined), 'undefined is not NaN');
    ok(!_.isNaN(null), 'null is not NaN');
    ok(!_.isNaN(0), '0 is not NaN');
    ok(_.isNaN(NaN), 'but NaN is');
    ok(_.isNaN(iNaN), 'even from another frame');
    ok(_.isNaN(new Number(NaN)), 'wrapped NaN is still NaN');
  });

  test('isNull', function() {
    ok(!_.isNull(undefined), 'undefined is not null');
    ok(!_.isNull(NaN), 'NaN is not null');
    ok(_.isNull(null), 'but null is');
    ok(_.isNull(iNull), 'even from another frame');
  });

  test('isUndefined', function() {
    ok(!_.isUndefined(1), 'numbers are defined');
    ok(!_.isUndefined(null), 'null is defined');
    ok(!_.isUndefined(false), 'false is defined');
    ok(!_.isUndefined(NaN), 'NaN is defined');
    ok(_.isUndefined(), 'nothing is undefined');
    ok(_.isUndefined(undefined), 'undefined is undefined');
    ok(_.isUndefined(iUndefined), 'even from another frame');
  });

  if (window.ActiveXObject) {
    test('IE host objects', function() {
      var xml = new ActiveXObject('Msxml2.DOMDocument.3.0');
      ok(!_.isNumber(xml));
      ok(!_.isBoolean(xml));
      ok(!_.isNaN(xml));
      ok(!_.isFunction(xml));
      ok(!_.isNull(xml));
      ok(!_.isUndefined(xml));
    });
  }

  test('tap', function() {
    var intercepted = null;
    var interceptor = function(obj) { intercepted = obj; };
    var returned = _.tap(1, interceptor);
    equal(intercepted, 1, 'passes tapped object to interceptor');
    equal(returned, 1, 'returns tapped object');

    returned = _([1,2,3]).chain().
      map(function(n){ return n * 2; }).
      max().
      tap(interceptor).
      value();
    ok(returned == 6 && intercepted == 6, 'can use tapped objects in a chain');
  });

  test("has", function () {
    var obj = {foo: "bar", func: function () {} };
    ok(_.has(obj, "foo"), "has() checks that the object has a property.");
    ok(_.has(obj, "baz") == false, "has() returns false if the object doesn't have the property.");
    ok(_.has(obj, "func"), "has() works for functions too.");
    obj.hasOwnProperty = null;
    ok(_.has(obj, "foo"), "has() works even when the hasOwnProperty method is deleted.");
    var child = {};
    child.prototype = obj;
    ok(_.has(child, "foo") == false, "has() does not check the prototype chain for a property.");
  });

  test("matches", function() {
    var moe = {name: 'Moe Howard', hair: true};
    var curly = {name: 'Curly Howard', hair: false};
    var stooges = [moe, curly];
    ok(_.find(stooges, _.matches({hair: false})) === curly, "returns a predicate that can be used by finding functions.");
    ok(_.find(stooges, _.matches(moe)) === moe, "can be used to locate an object exists in a collection.");
    deepEqual(_.where([null, undefined], {a: 1}), [], 'Do not throw on null values.');
    deepEqual(_.where([null, undefined], null), [null, undefined], 'null matches null');
    deepEqual(_.where([null, undefined], {}), [null, undefined], 'null matches {}');
  });

})();