Fixes #748 -- removes support for custom isEqual semantics within _.i…

…sEqual

test/objects.js

@@ -342,58 +342,6 @@ $(document).ready(function() {
     ok(_.isEqual(isEqualObjClone, isEqualObj), 'Commutative equality is implemented for objects with custom `isEqual` methods');
     ok(!_.isEqual(isEqualObj, {}), 'Objects that do not implement equivalent `isEqual` methods are not equal');
     ok(!_.isEqual({}, isEqualObj), 'Commutative equality is implemented for objects with different `isEqual` methods');
-
-    // Custom `isEqual` methods - comparing different types
-    LocalizedString = (function() {
-      function LocalizedString(id) { this.id = id; this.string = (this.id===10)? 'Bonjour': ''; }
-      LocalizedString.prototype.isEqual = function(that) {
-        if (_.isString(that)) return this.string == that;
-        else if (that instanceof LocalizedString) return this.id == that.id;
-        return false;
-      };
-      return LocalizedString;
-    })();
-    var localized_string1 = new LocalizedString(10), localized_string2 = new LocalizedString(10), localized_string3 = new LocalizedString(11);
-    ok(_.isEqual(localized_string1, localized_string2), 'comparing same typed instances with same ids');
-    ok(!_.isEqual(localized_string1, localized_string3), 'comparing same typed instances with different ids');
-    ok(_.isEqual(localized_string1, 'Bonjour'), 'comparing different typed instances with same values');
-    ok(_.isEqual('Bonjour', localized_string1), 'comparing different typed instances with same values');
-    ok(!_.isEqual('Bonjour', localized_string3), 'comparing two localized strings with different ids');
-    ok(!_.isEqual(localized_string1, 'Au revoir'), 'comparing different typed instances with different values');
-    ok(!_.isEqual('Au revoir', localized_string1), 'comparing different typed instances with different values');
-
-    // Custom `isEqual` methods - comparing with serialized data
-    Date.prototype.toJSON = function() {
-      return {
-        _type:'Date',
-        year:this.getUTCFullYear(),
-        month:this.getUTCMonth(),
-        day:this.getUTCDate(),
-        hours:this.getUTCHours(),
-        minutes:this.getUTCMinutes(),
-        seconds:this.getUTCSeconds()
-      };
-    };
-    Date.prototype.isEqual = function(that) {
-      var this_date_components = this.toJSON();
-      var that_date_components = (that instanceof Date) ? that.toJSON() : that;
-      delete this_date_components['_type']; delete that_date_components['_type'];
-      return _.isEqual(this_date_components, that_date_components);
-    };
-
-    var date = new Date();
-    var date_json = {
-      _type:'Date',
-      year:date.getUTCFullYear(),
-      month:date.getUTCMonth(),
-      day:date.getUTCDate(),
-      hours:date.getUTCHours(),
-      minutes:date.getUTCMinutes(),
-      seconds:date.getUTCSeconds()
-    };
-
-    ok(_.isEqual(date_json, date), 'serialized date matches date');
-    ok(_.isEqual(date, date_json), 'date matches serialized date');
   });
 
   test("isEmpty", function() {

underscore.js

@@ -781,9 +781,6 @@
     // Unwrap any wrapped objects.
     if (a instanceof _) a = a._wrapped;
     if (b instanceof _) b = b._wrapped;
-    // Invoke a custom `isEqual` method if one is provided.
-    if (a.isEqual && _.isFunction(a.isEqual)) return a.isEqual(b);
-    if (b.isEqual && _.isFunction(b.isEqual)) return b.isEqual(a);
     // Compare `[[Class]]` names.
     var className = toString.call(a);
     if (className != toString.call(b)) return false;