Added local() function to request + tests

lib/express/request.js

@@ -135,6 +135,37 @@ http.IncomingMessage.prototype.param = function(name){
     }
 };
 
+/**
+ * Gets/Sets a request local variable
+ *
+ *    To set a value:
+ *       req.local('userId', 'abc123');
+ *
+ *    To get a value:
+ *       var userId = req.local('userId');
+ *
+ * Useful when chaining routes with next()
+ * The first route handler can set a variable on
+ * the request, which can be accessed by the next
+ * route handler.  Common use case is authentication
+ * filters, which can set a 'user' object that can
+ * be accessed downstream on the request.
+ */
+
+http.IncomingMessage.prototype.local = function(name, value) {
+    if (!this.locals) {
+        this.locals = {};
+    }
+
+    if (value) {
+        // set case
+        this.locals[name] = value;
+    }
+    else {
+        return this.locals[name];
+    }
+};
+
 /**
  * Queue flash `msg` of the given `type`.
  *

test/request.test.js

@@ -150,8 +150,29 @@ module.exports = {
             res.send('ok');
         });
 
+        assert.response(app,
+            { url: '/' },
+            { body: 'ok' });
+    },
+
+    'test #local()': function(assert) {
+        var app = express.createServer();
+
+	app.get('/', function(req, res) {
+	    assert.eql(undefined, req.local('userId'));
+
+            req.local('userId', 'abc');
+            assert.eql('abc', req.local('userId'));
+
+            req.local('userId', ['a','b']);
+            assert.eql(['a','b'], req.local('userId'));
+
+            res.send('ok');
+	});
+
         assert.response(app,
             { url: '/' },
             { body: 'ok' });
     }
+
 };