Can no longer set values of undeclared static properties

lib/class_builder.js

@@ -114,8 +114,15 @@ exports.ClassBase = function Class() {};
  *
  * @return  {undefined}
  */
-exports.ClassBase.$ = function( prop )
+exports.ClassBase.$ = function( prop, val )
 {
+    if ( val !== undefined )
+    {
+        throw ReferenceError(
+            "Cannot set value of undeclared static property '" + prop + "'"
+        );
+    }
+
     return undefined;
 };
 

test/test-class_builder-static.js

@@ -396,3 +396,23 @@ var common    = require( './common' ),
     );
 } )();
 
+
+/**
+ * Users should not be permitted to set values of static properties that have
+ * not been declared.
+ */
+( function testAttemptingToSetUndeclaredStaticPropertyResultsInException()
+{
+    assert.throws(
+        function()
+        {
+            // should throw an exception since property 'foo' has not been
+            // declared
+            builder.build( {} ).$( 'foo', 'val' );
+        },
+        ReferenceError,
+        "Attempting to set an undeclaraed static property results in an " +
+            "exception"
+    );
+} )();
+