Added test to ensure same visibility de-escalation rules apply to concrete implementations of Interface methods

test/test-class-visibility.js

@@ -25,6 +25,7 @@
 var common    = require( './common' ),
     assert    = require( 'assert' ),
     Class     = common.require( 'class' ),
+    Interface = common.require( 'interface' ),
     propobj   = common.require( 'propobj' ),
 
     pub  = 'foo',
@@ -638,3 +639,21 @@ var common  = require( './common' ),
     );
 } )();
 
+
+/**
+ * Concrete implementations of interfaces should have to follow the same
+ * visibility de-escalation rules as defined in the above tests (otherwise, that
+ * defeats the purpose of an interface). In other words, they must be public.
+ */
+( function testVisibilityDeescalationRulesApplyToInterfaces()
+{
+    assert.throws( function()
+    {
+        Class.implement( Interface( { 'abstract public foo': [] } ) ).extend(
+        {
+            // should throw an exception; visibility de-escalation
+            'protected foo': function() {},
+        } );
+    }, Error, "Cannot de-escalate visibility for interface members" );
+} )();
+