From 465088213b2d884fe09613aed207eb92ceaeef27 Mon Sep 17 00:00:00 2001
From: Ryan Petrello <lists@ryanpetrello.com>
Date: Fri, 20 Feb 2015 09:39:54 -0500
Subject: [PATCH] Prevent @expose(generic=True) on special methods (_route,
 _lookup, _default).

Change-Id: Ie180cc4092ab1457dd97176cc72c563e1d4c561f
---
 pecan/decorators.py         |  5 +++++
 pecan/tests/test_generic.py | 23 +++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/pecan/decorators.py b/pecan/decorators.py
index ed054ec..36d33fa 100644
--- a/pecan/decorators.py
+++ b/pecan/decorators.py
@@ -55,6 +55,11 @@ def expose(template=None,
 
         # handle generic controllers
         if generic:
+            if f.__name__ in ('_default', '_lookup', '_route'):
+                raise ValueError(
+                    'The special method %s cannot be used as a generic '
+                    'controller' % f.__name__
+                )
             cfg['generic'] = True
             cfg['generic_handlers'] = dict(DEFAULT=f)
             cfg['allowed_methods'] = []
diff --git a/pecan/tests/test_generic.py b/pecan/tests/test_generic.py
index 19127fc..0478799 100644
--- a/pecan/tests/test_generic.py
+++ b/pecan/tests/test_generic.py
@@ -86,3 +86,26 @@ class TestGeneric(PecanTestCase):
         r = app.delete('/sub/sub/joe/is/cool')
         assert r.status_int == 200
         assert r.body == b_(dumps(dict(result='joe', args='is, cool')))
+
+
+class TestGenericWithSpecialMethods(PecanTestCase):
+
+    def test_generics_not_allowed(self):
+
+        class C(object):
+
+            def _default(self):
+                pass
+
+            def _lookup(self):
+                pass
+
+            def _route(self):
+                pass
+
+        for method in (C._default, C._lookup, C._route):
+            self.assertRaises(
+                ValueError,
+                expose(generic=True),
+                getattr(method, '__func__', method)
+            )