Much more testing of Facet, getting closer to 100%.

@@ -33,6 +33,7 @@ define(function(require) {
     var Facet = Backbone.Model.extend({
         defaults: function defaults() {
             return {
+                checkedKeys: [],
                 formName: null,
                 query: null,
                 suggestions: [],
@@ -110,7 +111,7 @@ define(function(require) {
                             var newChecked = checkedKeys[facetItem.get('key')];
                             var currentChecked = facetItem.get('checked');
                             if (newChecked !== currentChecked) {
-                                facetItem.set('checked', newChecked);
+                                facetItem.set('checked', !!newChecked);
                             }
                             if (facetItem.get('checked')) {
                                 checkedCount++;
@@ -128,19 +129,6 @@ define(function(require) {
             if (!sortKeyExtractor) {
                 sortKeyExtractor = getItemKeyAccessor;
             }
-            var comparator = options.comparator;
-            if (!comparator) {
-                comparator = Sort.standard;
-            } else if (typeof comparator === 'string') {
-                comparator = Sort[comparator];
-            }
-            switch (options.facetType) {
-                case 'year':
-                case 'range':
-                case 'interval':
-                    comparator = wrapComparatorForAllBeforeAfter(comparator, ['all', 'before'].indexOf(options.other) !== -1, ['all', 'after'].indexOf(options.other) !== -1);
-                    break;
-            }
             var formatter = options.formatter;
             if (!formatter) {
                 var labelMap = options.labelMap;
@@ -155,21 +143,46 @@ define(function(require) {
                 }
             }
             this.formatter = formatter;
-            comparator = (function(comparator) {
-                return function facetItemValue(a, b) {
-                    var keyA = sortKeyExtractor(a);
-                    var keyB = sortKeyExtractor(b);
-                    switch (this.get('orderByDirection')) {
-                        case 'desc':
-                            var tmp = keyA;
-                            keyA = keyB;
-                            keyB = tmp;
-                            break;
-                    }
-                    return comparator.call(this, sortKeyExtractor(a), sortKeyExtractor(b));
-                };
-            })(comparator);
-            this.set('items', new ItemCollection([], {comparator: comparator}));
+            this.on('change:comparator change:orderByDirection', function() {
+                var comparator = this.get('comparator');
+                if (!comparator) {
+                    comparator = Sort.standard;
+                } else if (typeof comparator === 'string') {
+                    comparator = Sort[comparator];
+                }
+                switch (options.facetType) {
+                    case 'year':
+                    case 'range':
+                    case 'interval':
+                        comparator = wrapComparatorForAllBeforeAfter(comparator, ['all', 'before'].indexOf(options.other) !== -1, ['all', 'after'].indexOf(options.other) !== -1);
+                        break;
+                }
+                var facet = this;
+                comparator = (function(comparator) {
+                    return function facetItemValue(a, b) {
+                        var keyA = sortKeyExtractor(a);
+                        var keyB = sortKeyExtractor(b);
+                        switch (facet.get('orderByDirection')) {
+                            case 'desc':
+                                var tmp = keyA;
+                                keyA = keyB;
+                                keyB = tmp;
+                                break;
+                        }
+                        return comparator.call(facet, keyA, keyB);
+                    };
+                })(comparator);
+                var items = this.get('items');
+                items.comparator = comparator;
+                items.sort();
+            }, this);
+
+            this.set('items', new ItemCollection([]));
+            this.set('comparator', options.comparator, {silent: true});
+            this.trigger('change:comparator');
+            this.get('items').on('item-change', function() {
+                this.trigger('item-change');
+            }, this);
             this.facetType = options.facetType;
             this.facetStats = options.facetStats;
             this.other = options.other;
@@ -243,7 +256,7 @@ define(function(require) {
             checked: false,
             hidden: false,
         },
-        _initialize: function(data, options) {
+        initialize: function(data, options) {
             this.on('add', function(model, parent, options) {
                 // added to a collection
                 this.on('change:checked', function() {