Added ability to set and trigger the active warning handler

lib/warn.js

@@ -22,6 +22,12 @@
  * @package core
  */
 
+/**
+ * Active warning handler
+ * @type {function()}
+ */
+var _handler = null;
+
 
 /**
  * Permits wrapping an exception as a warning
@@ -128,3 +134,35 @@ exports.handlers = {
     },
 };
 
+
+/**
+ * Sets the active warning handler
+ *
+ * You may use any of the predefined warning handlers or pass your own function.
+ *
+ * @param {function( Warning )} handler warning handler
+ *
+ * @return {undefined}
+ */
+exports.setHandler = function( handler )
+{
+    _handler = handler;
+};
+
+
+/**
+ * Handles a warning using the active warning handler
+ *
+ * @param {Warning} warning warning to handle
+ *
+ * @return {undefined}
+ */
+exports.handle = function( warning )
+{
+    _handler( warning );
+}
+
+
+// set the default handler
+_handler = exports.handlers.log;
+

test/test-warn-impl.js

@@ -0,0 +1,83 @@
+/**
+ * Tests warning system implementation
+ *
+ *  Copyright (C) 2010 Mike Gerwitz
+ *
+ *  This file is part of ease.js.
+ *
+ *  ease.js is free software: you can redistribute it and/or modify it under the
+ *  terms of the GNU Lesser General Public License as published by the Free
+ *  Software Foundation, either version 3 of the License, or (at your option)
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author  Mike Gerwitz
+ * @package test
+ */
+
+var common  = require( './common' ),
+    assert  = require( 'assert' ),
+    warn    = common.require( 'warn' )
+;
+
+
+/**
+ * The default warning handler should be the 'log' handler. This is a friendly
+ * compromise that will allow the developer to be warned of potential issues
+ * without affecting program execution.
+ */
+( function testDefaultHandlerIsLogger()
+{
+    // back up console object
+    var console_ = ( typeof console !== 'undefined' ) ? console : undefined,
+        called   = false;
+
+    // stub it
+    console = {
+        warn: function()
+        {
+            called = true;
+        },
+    };
+
+    warn.handle( warn.Warning( Error( 'foo' ) ) );
+
+    assert.ok( called,
+        "Default handler will log to console"
+    );
+
+    // restore console
+    console = console_;
+} )();
+
+
+/**
+ * The warning handler can be altered at runtime. Ensure we can set it and call
+ * it appropriately. We do not need to use one of the pre-defined handlers.
+ */
+( function testCanSetAndCallWarningHandler()
+{
+    var given,
+        warning = warn.Warning( Error( 'foo' ) );
+
+    // set a stub warning handler
+    warn.setHandler( function( warn )
+    {
+        given = warn;
+    } );
+
+    // trigger the handler
+    warn.handle( warning );
+
+    assert.deepEqual( given, warning,
+        "Set warning handler should be called with given Warning"
+    );
+} )();
+