Resolve a bug that mixes up argument order for generic functions.

When context locals are disabled, the order of arguments passed explicitly to
generic controller handlers is incorrect (and causes the user to interact with
e.g., a Response object, when they're really getting a Request object).

Fixes-bug: 1374683
Change-Id: I5922b0a441f1ebae032d5b0d64c9ee0f4cf018e0

2 files changed, 96 insertions, 3 deletions

diff --git a/pecan/core.py b/pecan/core.py
index 934931a..d5e4bc2 100644
--- a/pecan/core.py
+++ b/pecan/core.py
@@ -11,6 +11,10 @@ import operator
 import types
 
 import six
+if six.PY3:
+    from .compat import is_bound_method as ismethod
+else:
+    from inspect import ismethod
 
 from webob import (Request as WebObRequest, Response as WebObResponse, exc,
                    acceptparse)
@@ -737,7 +741,13 @@ class ExplicitPecan(PecanBase):
         args, varargs, kwargs = super(ExplicitPecan, self).get_args(
             state, all_params, remainder, argspec, im_self
         )
-        args = [state.request, state.response] + args
+
+        if ismethod(state.controller):
+            args = [state.request, state.response] + args
+        else:
+            # generic controllers have an explicit self *first*
+            # (because they're decorated functions, not instance methods)
+            args[1:1] = [state.request, state.response]
         return args, varargs, kwargs
 
 
diff --git a/pecan/tests/test_no_thread_locals.py b/pecan/tests/test_no_thread_locals.py
index a114840..0345391 100644
--- a/pecan/tests/test_no_thread_locals.py
+++ b/pecan/tests/test_no_thread_locals.py
@@ -1,4 +1,5 @@
-from json import dumps
+import time
+from json import dumps, loads
 import warnings
 
 from webtest import TestApp
@@ -7,7 +8,7 @@ from six import u as u_
 import webob
 import mock
 
-from pecan import Pecan, expose, abort
+from pecan import Pecan, expose, abort, Request, Response
 from pecan.rest import RestController
 from pecan.hooks import PecanHook, HookController
 from pecan.tests import PecanTestCase
@@ -1355,3 +1356,85 @@ class TestHooks(PecanTestCase):
         assert run_hook[3] == 'inside_sub'
         assert run_hook[4] == 'after1'
         assert run_hook[5] == 'after2'
+
+
+class TestGeneric(PecanTestCase):
+
+    @property
+    def root(self):
+        class RootController(object):
+
+            def __init__(self, unique):
+                self.unique = unique
+
+            @expose(generic=True, template='json')
+            def index(self, req, resp):
+                assert self.__class__.__name__ == 'RootController'
+                assert isinstance(req, Request)
+                assert isinstance(resp, Response)
+                assert self.unique == req.headers.get('X-Unique')
+                return {'hello': 'world'}
+
+            @index.when(method='POST', template='json')
+            def index_post(self, req, resp):
+                assert self.__class__.__name__ == 'RootController'
+                assert isinstance(req, Request)
+                assert isinstance(resp, Response)
+                assert self.unique == req.headers.get('X-Unique')
+                return req.json
+
+            @expose(template='json')
+            def echo(self, req, resp):
+                assert self.__class__.__name__ == 'RootController'
+                assert isinstance(req, Request)
+                assert isinstance(resp, Response)
+                assert self.unique == req.headers.get('X-Unique')
+                return req.json
+
+            @expose(template='json')
+            def extra(self, req, resp, first, second):
+                assert self.__class__.__name__ == 'RootController'
+                assert isinstance(req, Request)
+                assert isinstance(resp, Response)
+                assert self.unique == req.headers.get('X-Unique')
+                return {'first': first, 'second': second}
+
+        return RootController
+
+    def test_generics_with_im_self_default(self):
+        uniq = str(time.time())
+        with mock.patch('threading.local', side_effect=AssertionError()):
+            app = TestApp(Pecan(self.root(uniq), use_context_locals=False))
+            r = app.get('/', headers={'X-Unique': uniq})
+            assert r.status_int == 200
+            json_resp = loads(r.body.decode())
+            assert json_resp['hello'] == 'world'
+
+    def test_generics_with_im_self_with_method(self):
+        uniq = str(time.time())
+        with mock.patch('threading.local', side_effect=AssertionError()):
+            app = TestApp(Pecan(self.root(uniq), use_context_locals=False))
+            r = app.post_json('/', {'foo': 'bar'}, headers={'X-Unique': uniq})
+            assert r.status_int == 200
+            json_resp = loads(r.body.decode())
+            assert json_resp['foo'] == 'bar'
+
+    def test_generics_with_im_self_with_path(self):
+        uniq = str(time.time())
+        with mock.patch('threading.local', side_effect=AssertionError()):
+            app = TestApp(Pecan(self.root(uniq), use_context_locals=False))
+            r = app.post_json('/echo/', {'foo': 'bar'},
+                              headers={'X-Unique': uniq})
+            assert r.status_int == 200
+            json_resp = loads(r.body.decode())
+            assert json_resp['foo'] == 'bar'
+
+    def test_generics_with_im_self_with_extra_args(self):
+        uniq = str(time.time())
+        with mock.patch('threading.local', side_effect=AssertionError()):
+            app = TestApp(Pecan(self.root(uniq), use_context_locals=False))
+            r = app.get('/extra/123/456',  headers={'X-Unique': uniq})
+            assert r.status_int == 200
+            json_resp = loads(r.body.decode())
+            assert json_resp['first'] == '123'
+            assert json_resp['second'] == '456'