Invoke router.param() only when route matches

fixes #2206

History.md

@@ -11,6 +11,7 @@ unreleased
  * deprecate things with `depd` module
  * fix behavior when handling request without routes
  * fix handling when `route.all` is only route
+ * invoke `router.param()` only when route matches
  * restore `req.params` after invoking router
  * use `finalhandler` for final response handling
  * use `media-typer` to alter content-type charset

lib/router/index.js

@@ -191,12 +191,20 @@ proto.handle = function(req, res, done) {
           return next(err);
         }
 
-        req.route = route;
+        var has_method = route._handles_method(method);
 
-        // we can now dispatch to the route
-        if (method === 'options' && !route.methods['options']) {
+        // build up automatic options response
+        if (!has_method && method === 'options') {
           options.push.apply(options, route._options());
         }
+
+        // don't even bother
+        if (!has_method && method !== 'head') {
+          return next();
+        }
+
+        // we can now dispatch to the route
+        req.route = route;
       }
 
       // Capture one-time layer values

lib/router/route.js

@@ -28,6 +28,24 @@ function Route(path) {
   this.methods = {};
 }
 
+/**
+ * @api private
+ */
+
+Route.prototype._handles_method = function _handles_method(method) {
+  if (this.methods._all) {
+    return true;
+  }
+
+  method = method.toLowerCase();
+
+  if (method === 'head' && !this.methods['head']) {
+    method = 'get';
+  }
+
+  return Boolean(this.methods[method]);
+};
+
 /**
  * @return {Array} supported HTTP methods
  * @api private
@@ -137,6 +155,7 @@ Route.prototype.all = function(){
       throw new Error(msg);
     }
 
+    self.methods._all = true;
     self.stack.push({ handle: fn });
   });
 

test/app.param.js

@@ -177,6 +177,31 @@ describe('app', function(){
       .expect('loki', done);
     })
 
+    it('should not invoke without route handler', function(done) {
+      var app = express();
+
+      app.param('thing', function(req, res, next, thing) {
+        req.thing = thing;
+        next();
+      });
+
+      app.param('user', function(req, res, next, user) {
+        next(new Error('invalid invokation'));
+      });
+
+      app.post('/:user', function(req, res, next) {
+        res.send(req.params.user);
+      });
+
+      app.get('/:thing', function(req, res, next) {
+        res.send(req.thing);
+      });
+
+      request(app)
+      .get('/bob')
+      .expect(200, 'bob', done);
+    })
+
     it('should work with encoded values', function(done){
       var app = express();