text: $(document).ready(function() {
  
    // Variable to catch the last request.
    var lastRequest = null;
    // Variable to catch ajax params.
    var ajaxParams = null;
    var sync = Backbone.sync;
    var ajax = $.ajax;
    var urlRoot = null;
  
    var proxy = Backbone.Model.extend();
    var klass = Backbone.Collection.extend({
      url : function() { return '/collection'; }
    });
    var doc, collection;
  
    module("Backbone.Model", {
  
      setup: function() {
        doc = new proxy({
          id     : '1-the-tempest',
          title  : "The Tempest",
          author : "Bill Shakespeare",
          length : 123
        });
        collection = new klass();
        collection.add(doc);
  
        Backbone.sync = function(method, model, options) {
          lastRequest = {
            method: method,
            model: model,
            options: options
          };
          sync.apply(this, arguments);
        };
        $.ajax = function(params) { ajaxParams = params; };
        urlRoot = Backbone.Model.prototype.urlRoot;
        Backbone.Model.prototype.urlRoot = '/';
      },
  
      teardown: function() {
        Backbone.sync = sync;
        $.ajax = ajax;
        Backbone.Model.prototype.urlRoot = urlRoot;
      }
  
    });
  
    test("Model: initialize", function() {
      var Model = Backbone.Model.extend({
        initialize: function() {
          this.one = 1;
          equal(this.collection, collection);
        }
      });
      var model = new Model({}, {collection: collection});
      equal(model.one, 1);
      equal(model.collection, collection);
    });
  
    test("Model: initialize with attributes and options", function() {
      var Model = Backbone.Model.extend({
        initialize: function(attributes, options) {
          this.one = options.one;
        }
      });
      var model = new Model({}, {one: 1});
      equal(model.one, 1);
    });
  
    test("Model: initialize with parsed attributes", function() {
      var Model = Backbone.Model.extend({
        parse: function(obj) {
          obj.value += 1;
          return obj;
        }
      });
      var model = new Model({value: 1}, {parse: true});
      equal(model.get('value'), 2);
    });
  
    test("Model: url", function() {
      doc.urlRoot = null;
      equal(doc.url(), '/collection/1-the-tempest');
      doc.collection.url = '/collection/';
      equal(doc.url(), '/collection/1-the-tempest');
      doc.collection = null;
      raises(function() { doc.url(); });
      doc.collection = collection;
    });
  
    test("Model: url when using urlRoot, and uri encoding", function() {
      var Model = Backbone.Model.extend({
        urlRoot: '/collection'
      });
      var model = new Model();
      equal(model.url(), '/collection');
      model.set({id: '+1+'});
      equal(model.url(), '/collection/%2B1%2B');
    });
  
    test("Model: url when using urlRoot as a function to determine urlRoot at runtime", function() {
      var Model = Backbone.Model.extend({
        urlRoot: function() {
          return '/nested/' + this.get('parent_id') + '/collection';
        }
      });
  
      var model = new Model({parent_id: 1});
      equal(model.url(), '/nested/1/collection');
      model.set({id: 2});
      equal(model.url(), '/nested/1/collection/2');
    });
  
    test("Model: clone", function() {
      var a = new Backbone.Model({ 'foo': 1, 'bar': 2, 'baz': 3});
      var b = a.clone();
      equal(a.get('foo'), 1);
      equal(a.get('bar'), 2);
      equal(a.get('baz'), 3);
      equal(b.get('foo'), a.get('foo'), "Foo should be the same on the clone.");
      equal(b.get('bar'), a.get('bar'), "Bar should be the same on the clone.");
      equal(b.get('baz'), a.get('baz'), "Baz should be the same on the clone.");
      a.set({foo : 100});
      equal(a.get('foo'), 100);
      equal(b.get('foo'), 1, "Changing a parent attribute does not change the clone.");
    });
  
    test("Model: isNew", function() {
      var a = new Backbone.Model({ 'foo': 1, 'bar': 2, 'baz': 3});
      ok(a.isNew(), "it should be new");
      a = new Backbone.Model({ 'foo': 1, 'bar': 2, 'baz': 3, 'id': -5 });
      ok(!a.isNew(), "any defined ID is legal, negative or positive");
      a = new Backbone.Model({ 'foo': 1, 'bar': 2, 'baz': 3, 'id': 0 });
      ok(!a.isNew(), "any defined ID is legal, including zero");
      ok( new Backbone.Model({          }).isNew(), "is true when there is no id");
      ok(!new Backbone.Model({ 'id': 2  }).isNew(), "is false for a positive integer");
      ok(!new Backbone.Model({ 'id': -5 }).isNew(), "is false for a negative integer");
    });
  
    test("Model: get", function() {
      equal(doc.get('title'), 'The Tempest');
      equal(doc.get('author'), 'Bill Shakespeare');
    });
  
    test("Model: escape", function() {
      equal(doc.escape('title'), 'The Tempest');
      doc.set({audience: 'Bill & Bob'});
      equal(doc.escape('audience'), 'Bill &amp; Bob');
      doc.set({audience: 'Tim > Joan'});
      equal(doc.escape('audience'), 'Tim &gt; Joan');
      doc.set({audience: 10101});
      equal(doc.escape('audience'), '10101');
      doc.unset('audience');
      equal(doc.escape('audience'), '');
    });
  
    test("Model: has", function() {
      var a = new Backbone.Model();
      equal(a.has("name"), false);
      _([true, "Truth!", 1, false, '', 0]).each(function(value) {
        a.set({'name': value});
        equal(a.has("name"), true);
      });
      a.unset('name');
      equal(a.has('name'), false);
      _([null, undefined]).each(function(value) {
        a.set({'name': value});
        equal(a.has("name"), false);
      });
    });
  
    test("Model: set and unset", function() {
      expect(8);
      var a = new Backbone.Model({id: 'id', foo: 1, bar: 2, baz: 3});
      var changeCount = 0;
      a.on("change:foo", function() { changeCount += 1; });
      a.set({'foo': 2});
      ok(a.get('foo') == 2, "Foo should have changed.");
      ok(changeCount == 1, "Change count should have incremented.");
      a.set({'foo': 2}); // set with value that is not new shouldn't fire change event
      ok(a.get('foo') == 2, "Foo should NOT have changed, still 2");
      ok(changeCount == 1, "Change count should NOT have incremented.");
  
      a.validate = function(attrs) {
        equal(attrs.foo, void 0, "don't ignore values when unsetting");
      };
      a.unset('foo');
      equal(a.get('foo'), void 0, "Foo should have changed");
      delete a.validate;
      ok(changeCount == 2, "Change count should have incremented for unset.");
  
      a.unset('id');
      equal(a.id, undefined, "Unsetting the id should remove the id property.");
    });
  
    test("Model: multiple unsets", function() {
      var i = 0;
      var counter = function(){ i++; };
      var model = new Backbone.Model({a: 1});
      model.on("change:a", counter);
      model.set({a: 2});
      model.unset('a');
      model.unset('a');
      equal(i, 2, 'Unset does not fire an event for missing attributes.');
    });
  
    test("Model: unset and changedAttributes", function() {
      var model = new Backbone.Model({a: 1});
      model.unset('a', {silent: true});
      var changedAttributes = model.changedAttributes();
      ok('a' in changedAttributes, 'changedAttributes should contain unset properties');
  
      changedAttributes = model.changedAttributes();
      ok('a' in changedAttributes, 'changedAttributes should contain unset properties when running changedAttributes again after an unset.');
    });
  
    test("Model: using a non-default id attribute.", function() {
      var MongoModel = Backbone.Model.extend({idAttribute : '_id'});
      var model = new MongoModel({id: 'eye-dee', _id: 25, title: 'Model'});
      equal(model.get('id'), 'eye-dee');
      equal(model.id, 25);
      equal(model.isNew(), false);
      model.unset('_id');
      equal(model.id, undefined);
      equal(model.isNew(), true);
    });
  
    test("Model: set an empty string", function() {
      var model = new Backbone.Model({name : "Model"});
      model.set({name : ''});
      equal(model.get('name'), '');
    });
  
    test("Model: clear", function() {
      var changed;
      var model = new Backbone.Model({id: 1, name : "Model"});
      model.on("change:name", function(){ changed = true; });
      model.on("change", function() {
        var changedAttrs = model.changedAttributes();
        ok('name' in changedAttrs);
      });
      model.clear();
      equal(changed, true);
      equal(model.get('name'), undefined);
    });
  
    test("Model: defaults", function() {
      var Defaulted = Backbone.Model.extend({
        defaults: {
          "one": 1,
          "two": 2
        }
      });
      var model = new Defaulted({two: null});
      equal(model.get('one'), 1);
      equal(model.get('two'), null);
      Defaulted = Backbone.Model.extend({
        defaults: function() {
          return {
            "one": 3,
            "two": 4
          };
        }
      });
      var model = new Defaulted({two: null});
      equal(model.get('one'), 3);
      equal(model.get('two'), null);
    });
  
    test("Model: change, hasChanged, changedAttributes, previous, previousAttributes", function() {
      var model = new Backbone.Model({name : "Tim", age : 10});
      equal(model.changedAttributes(), false);
      model.on('change', function() {
        ok(model.hasChanged('name'), 'name changed');
        ok(!model.hasChanged('age'), 'age did not');
        ok(_.isEqual(model.changedAttributes(), {name : 'Rob'}), 'changedAttributes returns the changed attrs');
        equal(model.previous('name'), 'Tim');
        ok(_.isEqual(model.previousAttributes(), {name : "Tim", age : 10}), 'previousAttributes is correct');
      });
      model.set({name : 'Rob'}, {silent : true});
      equal(model.hasChanged(), true);
      equal(model.hasChanged('name'), true);
      model.change();
      equal(model.get('name'), 'Rob');
    });
  
    test("Model: changedAttributes", function() {
      var model = new Backbone.Model({a: 'a', b: 'b'});
      equal(model.changedAttributes(), false);
      equal(model.changedAttributes({a: 'a'}), false);
      equal(model.changedAttributes({a: 'b'}).a, 'b');
    });
  
    test("Model: change with options", function() {
      var value;
      var model = new Backbone.Model({name: 'Rob'});
      model.on('change', function(model, options) {
        value = options.prefix + model.get('name');
      });
      model.set({name: 'Bob'}, {silent: true});
      model.change({prefix: 'Mr. '});
      equal(value, 'Mr. Bob');
      model.set({name: 'Sue'}, {prefix: 'Ms. '});
      equal(value, 'Ms. Sue');
    });
  
    test("Model: change after initialize", function () {
      var changed = 0;
      var attrs = {id: 1, label: 'c'};
      var obj = new Backbone.Model(attrs);
      obj.on('change', function() { changed += 1; });
      obj.set(attrs);
      equal(changed, 0);
    });
  
    test("Model: save within change event", function () {
      var model = new Backbone.Model({firstName : "Taylor", lastName: "Swift"});
      model.on('change', function () {
        model.save();
        ok(_.isEqual(lastRequest.model, model));
      });
      model.set({lastName: 'Hicks'});
    });
  
    test("Model: validate after save", function() {
      var lastError, model = new Backbone.Model();
      model.validate = function(attrs) {
        if (attrs.admin) return "Can't change admin status.";
      };
      model.sync = function(method, model, options) {
        options.success.call(this, {admin: true});
      };
      model.save(null, {error: function(model, error) {
        lastError = error;
      }});
  
      equal(lastError, "Can't change admin status.");
    });
  
    test("Model: isValid", function() {
      var model = new Backbone.Model({valid: true});
      model.validate = function(attrs) {
        if (!attrs.valid) return "invalid";
      };
      equal(model.isValid(), true);
      equal(model.set({valid: false}), false);
      equal(model.isValid(), true);
      ok(model.set('valid', false, {silent: true}));
      equal(model.isValid(), false);
    });
  
    test("Model: save", function() {
      doc.save({title : "Henry V"});
      equal(lastRequest.method, 'update');
      ok(_.isEqual(lastRequest.model, doc));
    });
  
    test("Model: save in positional style", function() {
      var model = new Backbone.Model();
      model.sync = function(method, model, options) {
        options.success();
      };
      model.save('title', 'Twelfth Night');
      equal(model.get('title'), 'Twelfth Night');
    });
  
  
  
    test("Model: fetch", function() {
      doc.fetch();
      equal(lastRequest.method, 'read');
      ok(_.isEqual(lastRequest.model, doc));
    });
  
    test("Model: destroy", function() {
      doc.destroy();
      equal(lastRequest.method, 'delete');
      ok(_.isEqual(lastRequest.model, doc));
  
      var newModel = new Backbone.Model;
      equal(newModel.destroy(), false);
    });
  
    test("Model: non-persisted destroy", function() {
      var a = new Backbone.Model({ 'foo': 1, 'bar': 2, 'baz': 3});
      a.sync = function() { throw "should not be called"; };
      a.destroy();
      ok(true, "non-persisted model should not call sync");
    });
  
    test("Model: validate", function() {
      var lastError;
      var model = new Backbone.Model();
      model.validate = function(attrs) {
        if (attrs.admin != this.get('admin')) return "Can't change admin status.";
      };
      model.on('error', function(model, error) {
        lastError = error;
      });
      var result = model.set({a: 100});
      equal(result, model);
      equal(model.get('a'), 100);
      equal(lastError, undefined);
      result = model.set({admin: true}, {silent: true});
      equal(model.get('admin'), true);
      result = model.set({a: 200, admin: false});
      equal(lastError, "Can't change admin status.");
      equal(result, false);
      equal(model.get('a'), 100);
    });
  
    test("Model: validate on unset and clear", function() {
      var error;
      var model = new Backbone.Model({name: "One"});
      model.validate = function(attrs) {
        if (!attrs.name) {
          error = true;
          return "No thanks.";
        }
      };
      model.set({name: "Two"});
      equal(model.get('name'), 'Two');
      equal(error, undefined);
      model.unset('name');
      equal(error, true);
      equal(model.get('name'), 'Two');
      model.clear();
      equal(model.get('name'), 'Two');
      delete model.validate;
      model.clear();
      equal(model.get('name'), undefined);
    });
  
    test("Model: validate with error callback", function() {
      var lastError, boundError;
      var model = new Backbone.Model();
      model.validate = function(attrs) {
        if (attrs.admin) return "Can't change admin status.";
      };
      var callback = function(model, error) {
        lastError = error;
      };
      model.on('error', function(model, error) {
        boundError = true;
      });
      var result = model.set({a: 100}, {error: callback});
      equal(result, model);
      equal(model.get('a'), 100);
      equal(lastError, undefined);
      equal(boundError, undefined);
      result = model.set({a: 200, admin: true}, {error: callback});
      equal(result, false);
      equal(model.get('a'), 100);
      equal(lastError, "Can't change admin status.");
      equal(boundError, undefined);
    });
  
    test("Model: defaults always extend attrs (#459)", function() {
      var Defaulted = Backbone.Model.extend({
        defaults: {one: 1},
        initialize : function(attrs, opts) {
          equal(this.attributes.one, 1);
        }
      });
      var providedattrs = new Defaulted({});
      var emptyattrs = new Defaulted();
    });
  
    test("Model: Inherit class properties", function() {
      var Parent = Backbone.Model.extend({
        instancePropSame: function() {},
        instancePropDiff: function() {}
      }, {
        classProp: function() {}
      });
      var Child = Parent.extend({
        instancePropDiff: function() {}
      });
  
      var adult = new Parent;
      var kid   = new Child;
  
      equal(Child.classProp, Parent.classProp);
      notEqual(Child.classProp, undefined);
  
      equal(kid.instancePropSame, adult.instancePropSame);
      notEqual(kid.instancePropSame, undefined);
  
      notEqual(Child.prototype.instancePropDiff, Parent.prototype.instancePropDiff);
      notEqual(Child.prototype.instancePropDiff, undefined);
    });
  
    test("Model: Nested change events don't clobber previous attributes", function() {
      var A = Backbone.Model.extend({
        initialize: function() {
          this.on("change:state", function(a, newState) {
            equal(a.previous('state'), undefined);
            equal(newState, 'hello');
            // Fire a nested change event.
            this.set({ other: "whatever" });
          });
        }
      });
  
      var B = Backbone.Model.extend({
        initialize: function() {
          this.get("a").on("change:state", function(a, newState) {
            equal(a.previous('state'), undefined);
            equal(newState, 'hello');
          });
        }
      });
  
      var a = new A();
      var b = new B({a: a});
      a.set({state: 'hello'});
    });
  
    test("hasChanged/set should use same comparison", function() {
      expect(2);
      var changed = 0, model = new Backbone.Model({a: null});
      model.on('change', function() {
        ok(this.hasChanged('a'));
      })
      .on('change:a', function() {
        changed++;
      })
      .set({a: undefined});
      equal(changed, 1);
    });
  
    test("#582, #425, change:attribute callbacks should fire after all changes have occurred", 9, function() {
      var model = new Backbone.Model;
  
      var assertion = function() {
        equal(model.get('a'), 'a');
        equal(model.get('b'), 'b');
        equal(model.get('c'), 'c');
      };
  
      model.on('change:a', assertion);
      model.on('change:b', assertion);
      model.on('change:c', assertion);
  
      model.set({a: 'a', b: 'b', c: 'c'});
    });
  
    test("#871, set with attributes property", function() {
      var model = new Backbone.Model();
      model.set({attributes: true});
      ok(model.has('attributes'));
    });
  
    test("set value regardless of equality/change", function() {
      var model = new Backbone.Model({x: []});
      var a = [];
      model.set({x: a});
      ok(model.get('x') === a);
    });
  
    test("unset fires change for undefined attributes", 1, function() {
      var model = new Backbone.Model({x: undefined});
      model.on('change:x', function(){ ok(true); });
      model.unset('x');
    });
  
    test("set: undefined values", function() {
      var model = new Backbone.Model({x: undefined});
      ok('x' in model.attributes);
    });
  
    test("change fires change:attr", 1, function() {
      var model = new Backbone.Model({x: 1});
      model.set({x: 2}, {silent: true});
      model.on('change:x', function(){ ok(true); });
      model.change();
    });
  
    test("hasChanged is false after original values are set", function() {
      var model = new Backbone.Model({x: 1});
      model.on('change:x', function(){ ok(false); });
      model.set({x: 2}, {silent: true});
      ok(model.hasChanged());
      model.set({x: 1}, {silent: true});
      ok(!model.hasChanged());
    });
  
    test("save with `wait` succeeds without `validate`", function() {
      var model = new Backbone.Model();
      model.save({x: 1}, {wait: true});
      ok(lastRequest.model === model);
    });
  
    test("`hasChanged` for falsey keys", function() {
      var model = new Backbone.Model();
      model.set({x: true}, {silent: true});
      ok(!model.hasChanged(0));
      ok(!model.hasChanged(''));
    });
  
    test("`previous` for falsey keys", function() {
      var model = new Backbone.Model({0: true, '': true});
      model.set({0: false, '': false}, {silent: true});
      equal(model.previous(0), true);
      equal(model.previous(''), true);
    });
  
    test("`save` with `wait` sends correct attributes", function() {
      var changed = 0;
      var model = new Backbone.Model({x: 1, y: 2});
      model.on('change:x', function() { changed++; });
      model.save({x: 3}, {wait: true});
      deepEqual(JSON.parse(ajaxParams.data), {x: 3, y: 2});
      equal(model.get('x'), 1);
      equal(changed, 0);
      lastRequest.options.success({});
      equal(model.get('x'), 3);
      equal(changed, 1);
    });
  
    test("`save` with `wait` results in correct attributes if success is called during sync", function() {
      var changed = 0;
      var model = new Backbone.Model({x: 1, y: 2});
      model.sync = function(method, model, options) {
        options.success();
      };
      model.on("change:x", function() { changed++; });
      model.save({x: 3}, {wait: true});
      equal(model.get('x'), 3);
      equal(changed, 1);
    });
  
    test("save with wait validates attributes", 1, function() {
      var model = new Backbone.Model();
      model.validate = function() { ok(true); };
      model.save({x: 1}, {wait: true});
    });
  
    test("nested `set` during `'change:attr'`", function() {
      var events = [];
      var model = new Backbone.Model();
      model.on('all', function(event) { events.push(event); });
      model.on('change', function() {
        model.set({z: true}, {silent:true});
      });
      model.on('change:x', function() {
        model.set({y: true});
      });
      model.set({x: true});
      deepEqual(events, ['change:y', 'change:x', 'change']);
      events = [];
      model.change();
      deepEqual(events, ['change:z', 'change']);
    });
  
    test("nested `change` only fires once", 1, function() {
      var model = new Backbone.Model();
      model.on('change', function() {
        ok(true);
        model.change();
      });
      model.set({x: true});
    });
  
    test("no `'change'` event if no changes", function() {
      var model = new Backbone.Model();
      model.on('change', function() { ok(false); });
      model.change();
    });
  
    test("nested `set` during `'change'`", 6, function() {
      var count = 0;
      var model = new Backbone.Model();
      model.on('change', function() {
        switch(count++) {
          case 0:
            deepEqual(this.changedAttributes(), {x: true});
            equal(model.previous('x'), undefined);
            model.set({y: true});
            break;
          case 1:
            deepEqual(this.changedAttributes(), {y: true});
            equal(model.previous('x'), true);
            model.set({z: true});
            break;
          case 2:
            deepEqual(this.changedAttributes(), {z: true});
            equal(model.previous('y'), true);
            break;
          default:
            ok(false);
        }
      });
      model.set({x: true});
    });
  
    test("nested `'change'` with silent", 3, function() {
      var count = 0;
      var model = new Backbone.Model();
      model.on('change:y', function() { ok(true); });
      model.on('change', function() {
        switch(count++) {
          case 0:
            deepEqual(this.changedAttributes(), {x: true});
            model.set({y: true}, {silent: true});
            break;
          case 1:
            deepEqual(this.changedAttributes(), {y: true, z: true});
            break;
          default:
            ok(false);
        }
      });
      model.set({x: true});
      model.set({z: true});
    });
  
    test("nested `'change:attr'` with silent", 1, function() {
      var model = new Backbone.Model();
      model.on('change:y', function(){ ok(true); });
      model.on('change', function() {
        model.set({y: true}, {silent: true});
        model.set({z: true});
      });
      model.set({x: true});
    });
  
    test("multiple nested changes with silent", 1, function() {
      var model = new Backbone.Model();
      model.on('change:x', function() {
        model.set({y: 1}, {silent: true});
        model.set({y: 2});
      });
      model.on('change:y', function(model, val) {
        equal(val, 2);
      });
      model.set({x: true});
      model.change();
    });
  
    test("multiple nested changes with silent", function() {
      var changes = [];
      var model = new Backbone.Model();
      model.on('change:b', function(model, val) { changes.push(val); });
      model.on('change', function() {
        model.set({b: 1});
        model.set({b: 2}, {silent: true});
      });
      model.set({b: 0});
      deepEqual(changes, [0, 1, 1]);
      model.change();
      deepEqual(changes, [0, 1, 1, 2, 1]);
    });
  
    test("nested set multiple times", 1, function() {
      var model = new Backbone.Model();
      model.on('change:b', function() {
        ok(true);
      });
      model.on('change:a', function() {
        model.set({b: true});
        model.set({b: true});
      });
      model.set({a: true});
    });
  
    test("Backbone.wrapError triggers `'error'`", 12, function() {
      var resp = {};
      var options = {};
      var model = new Backbone.Model();
      model.on('error', error);
      var callback = Backbone.wrapError(null, model, options);
      callback(model, resp);
      callback(resp);
      callback = Backbone.wrapError(error, model, options);
      callback(model, resp);
      callback(resp);
      function error(_model, _resp, _options) {
        ok(model === _model);
        ok(resp === _resp);
        ok(options === _options);
      }
    });
  
  });
  