Initial implementation of natural class definition by invoking class module

lib/class.js

@@ -35,6 +35,43 @@ var util           = require( './util' ),
 var class_meta = {};
 
 
+/**
+ * This module may be invoked in order to provide a more natural looking class
+ * definition mechanism
+ *
+ * This may not be used to extend existing classes. To extend an existing class,
+ * use the class's extend() method. If unavailable (or extending a non-ease.js
+ * class/object), use the module's extend() method.
+ *
+ * @param  {Object}  def  class definition
+ *
+ * @return  {Class}  new class
+ */
+module.exports = function( def )
+{
+    // the class definition should be an object
+    if ( typeof def !== 'object' )
+    {
+        throw TypeError(
+            "Must provide class definition when declaring a new class"
+        );
+    }
+
+    // ensure we have the proper number of arguments (if they passed in too
+    // many, it may signify that they don't know what they're doing, and likely
+    // they're not getting the result they're looking for)
+    if ( arguments.length > 1 )
+    {
+        throw Error(
+            "Expecting one argument for Class definition; " +
+                arguments.length + " given."
+        );
+    }
+
+    return extend( def );
+};
+
+
 /**
  * Creates a class, inheriting either from the provided base class or the
  * default base class
@@ -43,7 +80,7 @@ var class_meta = {};
  *
  * @return  {Object}  extended class
  */
-exports.extend = function( base )
+module.exports.extend = function( base )
 {
     return extend.apply( this, arguments );
 };
@@ -56,12 +93,12 @@ exports.extend = function( base )
  *
  * @return  {Class}  new class containing interface abstractions
  */
-exports.implement = function()
+module.exports.implement = function()
 {
     var args = Array.prototype.slice.call( arguments );
 
     // apply to an empty (new) object
-    args.unshift( exports.extend() );
+    args.unshift( module.exports.extend() );
 
     return implement.apply( this, args );
 };
@@ -74,7 +111,7 @@ exports.implement = function()
  *
  * @return  {boolean}  true if class (created through ease.js), otherwise false
  */
-exports.isClass = function( obj )
+module.exports.isClass = function( obj )
 {
     obj = obj || {};
 
@@ -94,7 +131,7 @@ exports.isClass = function( obj )
  * @return  {boolean}  true if instance of class (created through ease.js),
  *                     otherwise false
  */
-exports.isClassInstance = function( obj )
+module.exports.isClassInstance = function( obj )
 {
     obj = obj || {};
 
@@ -117,7 +154,7 @@ exports.isClassInstance = function( obj )
  *
  * @return  {boolean}  true if instance is an instance of type, otherwise false
  */
-exports.isInstanceOf = function( type, instance )
+module.exports.isInstanceOf = function( type, instance )
 {
     var meta, implemented, i;
 
@@ -162,7 +199,7 @@ exports.isInstanceOf = function( type, instance )
  * accurately conveys the act of inheritance, implementing interfaces and
  * traits, etc.
  */
-exports.isA = exports.isInstanceOf;
+module.exports.isA = module.exports.isInstanceOf;
 
 
 /**
@@ -429,7 +466,7 @@ var implement = function()
     }
 
     // create a new class with the implemented abstract methods
-    var class_new = exports.extend( base, dest );
+    var class_new = module.exports.extend( base, dest );
     getMeta( class_new.__cid ).implemented = implemented;
 
     return class_new;
@@ -594,7 +631,7 @@ function attachInstanceOf( instance )
 {
     var method = function( type )
     {
-        return exports.isInstanceOf( type, instance );
+        return module.exports.isInstanceOf( type, instance );
     };
 
     util.defineSecureProp( instance, 'isInstanceOf', method );

test/test-class-extend.js

@@ -30,7 +30,25 @@ var foo_props = {
         one: 1,
         two: 2,
     },
-    Foo = Class.extend( foo_props );
+
+    // there are two different means of extending; we want to test them both
+    classes = [
+        Class.extend( foo_props ),
+        Class( foo_props ),
+    ],
+
+    class_count = classes.length
+
+    // will hold the class being tested
+    Foo = null
+;
+
+
+// Run all tests for both. This will ensure that, regardless of how the class is
+// created, it operates as it should. Fortunately, these tests are fairly quick.
+for ( var i = 0; i < class_count; i++ )
+{
+    Foo = classes[ i ];
 
     assert.ok(
         ( Foo.extend instanceof Function ),
@@ -223,6 +241,7 @@ assert.ok(
         ),
         "Instances of subtypes do not share property references"
     );
+}
 
 
 // otherwise it'll output the internal constructor code, which is especially
@@ -236,3 +255,41 @@ assert.ok(
     );
 } )();
 
+
+( function testInvokingClassModuleRequiresObjectAsArgumentIfCreating()
+{
+    assert.throws( function()
+        {
+            Class( 'moo' );
+            Class( 5 );
+            Class( false );
+            Class();
+        },
+        TypeError,
+        "Invoking class module requires object as argument if extending " +
+            "from base class"
+    );
+
+    var args = [ {}, 'one', 'two', 'three' ];
+
+    // we must only provide one argument if the first argument is an object (the
+    // class definition)
+    try
+    {
+        Class.apply( null, args );
+
+        // if all goes well, we don't get to this line
+        assert.fail(
+            "Only one argument for class definitions is permitted"
+        );
+    }
+    catch ( e )
+    {
+        assert.notEqual(
+            e.toString().match( args.length + ' given' ),
+            null,
+            "Class invocation should give argument count on error"
+        );
+    }
+} )();
+