Added isA() as an alias for isInstanceOf()

lib/class.js

@@ -106,6 +106,16 @@ exports.isInstanceOf = function( type, instance )
 };
 
 
+/**
+ * Alias for isInstanceOf()
+ *
+ * May read better in certain situations (e.g. Cat.isA( Mammal )) and more
+ * accurately conveys the act of inheritance, implementing interfaces and
+ * traits, etc.
+ */
+exports.isA = exports.isInstanceOf;
+
+
 /**
  * Default class implementation
  *
@@ -399,9 +409,12 @@ function attachExtend( func )
  */
 function attachInstanceOf( instance )
 {
-    util.defineSecureProp( instance, 'isInstanceOf', function( type )
+    var method = function( type )
     {
         return exports.isInstanceOf( type, instance );
-    });
+    };
+
+    util.defineSecureProp( instance, 'isInstanceOf', method );
+    util.defineSecureProp( instance, 'isA', method );
 }
 

test/test-class.js

@@ -112,6 +112,12 @@ assert.ok(
     "Class is not an instance of its instance"
 );
 
+assert.equal(
+    Class.isInstanceOf,
+    Class.isA,
+    "isA() is an alias for isInstanceOf()"
+);
+
 assert.ok(
     ( ( inst.isInstanceOf instanceof Function )
         && ( inst.isInstanceOf( Foo ) === true )
@@ -120,3 +126,9 @@ assert.ok(
     "Class instance contains partially applied isInstanceOf method"
 );
 
+assert.equal(
+    inst.isInstanceOf,
+    inst.isA,
+    "Class instance contains isA() alias for isInstanceOf() partially applied function"
+);
+