Catch an edge case in RestController routing and properly return an HTTP 400.

Change-Id: I0e57cf719a2c3372ebc61efe71a832b0482a0a3e

pecan/rest.py

@@ -43,6 +43,19 @@ class RestController(object):
             return argspec.args[3:]
         return argspec.args[1:]
 
+    def _handle_bad_rest_arguments(self, controller, remainder, request):
+        """
+        Ensure that the argspec for a discovered controller actually matched
+        the positional arguments in the request path.  If not, raise
+        a webob.exc.HTTPBadRequest.
+        """
+        argspec = self._get_args_for_controller(controller)
+        fixed_args = len(argspec) - len(
+            request.pecan.get('routing_args', [])
+        )
+        if len(remainder) < fixed_args:
+            abort(400)
+
     @expose()
     def _route(self, args, request=None):
         '''
@@ -89,10 +102,10 @@ class RestController(object):
                 _lookup_result = self._handle_lookup(args, request)
                 if _lookup_result:
                     return _lookup_result
-        except exc.HTTPNotFound:
+        except (exc.HTTPClientError, exc.HTTPNotFound):
             #
-            # If the matching handler results in a 404, attempt to handle
-            # a _lookup method (if it exists)
+            # If the matching handler results in a 400 or 404, attempt to
+            # handle a _lookup method (if it exists)
             #
             _lookup_result = self._handle_lookup(args, request)
             if _lookup_result:
@@ -201,14 +214,10 @@ class RestController(object):
 
         # route to a get_all or get if no additional parts are available
         if not remainder or remainder == ['']:
+            remainder = list(six.moves.filter(bool, remainder))
             controller = self._find_controller('get_all', 'get')
             if controller:
-                argspec = self._get_args_for_controller(controller)
-                fixed_args = len(argspec) - len(
-                    request.pecan.get('routing_args', [])
-                )
-                if len(remainder) < fixed_args:
-                    abort(404)
+                self._handle_bad_rest_arguments(controller, remainder, request)
                 return controller, []
             abort(404)
 
@@ -232,6 +241,7 @@ class RestController(object):
         # finally, check for the regular get_one/get requests
         controller = self._find_controller('get_one', 'get')
         if controller:
+            self._handle_bad_rest_arguments(controller, remainder, request)
             return controller, remainder
 
         abort(404)

pecan/tests/test_rest.py

@@ -7,7 +7,7 @@ except:
 
 from six import b as b_
 
-from pecan import abort, expose, make_app, response
+from pecan import abort, expose, make_app, response, redirect
 from pecan.rest import RestController
 from pecan.tests import PecanTestCase
 
@@ -681,6 +681,117 @@ class TestRestController(PecanTestCase):
         assert r.status_int == 200
         assert len(loads(r.body.decode())['items']) == 1
 
+    def test_nested_get_all(self):
+
+        class BarsController(RestController):
+
+            @expose()
+            def get_one(self, foo_id, id):
+                return '4'
+
+            @expose()
+            def get_all(self, foo_id):
+                return '3'
+
+        class FoosController(RestController):
+
+            bars = BarsController()
+
+            @expose()
+            def get_one(self, id):
+                return '2'
+
+            @expose()
+            def get_all(self):
+                return '1'
+
+        class RootController(object):
+            foos = FoosController()
+
+        # create the app
+        app = TestApp(make_app(RootController()))
+
+        r = app.get('/foos/')
+        assert r.status_int == 200
+        assert r.body == b_('1')
+
+        r = app.get('/foos/1/')
+        assert r.status_int == 200
+        assert r.body == b_('2')
+
+        r = app.get('/foos/1/bars/')
+        assert r.status_int == 200
+        assert r.body == b_('3')
+
+        r = app.get('/foos/1/bars/2/')
+        assert r.status_int == 200
+        assert r.body == b_('4')
+
+        r = app.get('/foos/bars/', status=400)
+        assert r.status_int == 400
+
+        r = app.get('/foos/bars/1', status=400)
+        assert r.status_int == 400
+
+    def test_nested_get_all_with_lookup(self):
+
+        class BarsController(RestController):
+
+            @expose()
+            def get_one(self, foo_id, id):
+                return '4'
+
+            @expose()
+            def get_all(self, foo_id):
+                return '3'
+
+            @expose('json')
+            def _lookup(self, id, *remainder):
+                redirect('/lookup-hit/')
+
+        class FoosController(RestController):
+
+            bars = BarsController()
+
+            @expose()
+            def get_one(self, id):
+                return '2'
+
+            @expose()
+            def get_all(self):
+                return '1'
+
+        class RootController(object):
+            foos = FoosController()
+
+        # create the app
+        app = TestApp(make_app(RootController()))
+
+        r = app.get('/foos/')
+        assert r.status_int == 200
+        assert r.body == b_('1')
+
+        r = app.get('/foos/1/')
+        assert r.status_int == 200
+        assert r.body == b_('2')
+
+        r = app.get('/foos/1/bars/')
+        assert r.status_int == 200
+        assert r.body == b_('3')
+
+        r = app.get('/foos/1/bars/2/')
+        assert r.status_int == 200
+        assert r.body == b_('4')
+
+        r = app.get('/foos/bars/', status=400)
+        assert r.status_int == 400
+
+        r = app.get('/foos/bars/', status=400)
+
+        r = app.get('/foos/bars/1')
+        assert r.status_int == 302
+        assert r.headers['Location'].endswith('/lookup-hit/')
+
     def test_bad_rest(self):
 
         class ThingsController(RestController):
@@ -773,16 +884,16 @@ class TestRestController(PecanTestCase):
 
         # test get_all
         r = app.get('/foos')
-        assert r.status_int == 200
-        assert r.body == b_(dumps(dict(items=FoosController.data)))
+        self.assertEqual(r.status_int, 200)
+        self.assertEqual(r.body, b_(dumps(dict(items=FoosController.data))))
 
         # test nested get_all
         r = app.get('/foos/1/bars')
-        assert r.status_int == 200
-        assert r.body == b_(dumps(dict(items=BarsController.data[1])))
+        self.assertEqual(r.status_int, 200)
+        self.assertEqual(r.body, b_(dumps(dict(items=BarsController.data[1]))))
 
         r = app.get('/foos/bars', expect_errors=True)
-        assert r.status_int == 404
+        self.assertEqual(r.status_int, 400)
 
     def test_custom_with_trailing_slash(self):