- If an ``application`` value of ``None`` is supplied to the ``create_server``

  constructor function, a ValueError is now raised eagerly instead of an error
  occuring during runtime.  See https://github.com/Pylons/waitress/pull/60

Closes #60

3 files changed, 19 insertions, 4 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index ae592be..6d5e7c1 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -16,6 +16,10 @@ Next release
 
 - Add a ``docs`` section to tox.ini that, when run, ensures docs can be built.
 
+- If an ``application`` value of ``None`` is supplied to the ``create_server``
+  constructor function, a ValueError is now raised eagerly instead of an error
+  occuring during runtime.  See https://github.com/Pylons/waitress/pull/60
+
 0.8.9 (2014-05-16)
 ------------------
 
diff --git a/waitress/server.py b/waitress/server.py
index 4d3d91a..87338c8 100644
--- a/waitress/server.py
+++ b/waitress/server.py
@@ -36,6 +36,11 @@ def create_server(application,
         server = create_server(app)
         server.run()
     """
+    if application is None:
+        raise ValueError(
+            'The "app" passed to ``create_server`` was ``None``.  You forgot '
+            'to return a WSGI app within your application.'
+            )
     adj = Adjustments(**kw)
     if adj.unix_socket and hasattr(socket, 'AF_UNIX'):
         cls = UnixWSGIServer
diff --git a/waitress/tests/test_server.py b/waitress/tests/test_server.py
index 8b48e10..0ff8871 100644
--- a/waitress/tests/test_server.py
+++ b/waitress/tests/test_server.py
@@ -2,9 +2,11 @@ import errno
 import socket
 import unittest
 
+dummy_app = object()
+
 class TestWSGIServer(unittest.TestCase):
 
-    def _makeOne(self, application, host='127.0.0.1', port=0,
+    def _makeOne(self, application=dummy_app, host='127.0.0.1', port=0,
                  _dispatcher=None, adj=None, map=None, _start=True,
                  _sock=None, _server=None):
         from waitress.server import create_server
@@ -18,7 +20,7 @@ class TestWSGIServer(unittest.TestCase):
             _sock=_sock)
 
     def _makeOneWithMap(self, adj=None, _start=True, host='127.0.0.1',
-                        port=0, app=None):
+                        port=0, app=dummy_app):
         sock = DummySock()
         task_dispatcher = DummyTaskDispatcher()
         map = {}
@@ -32,13 +34,17 @@ class TestWSGIServer(unittest.TestCase):
             _start=_start,
         )
 
+    def test_ctor_app_is_None(self):
+        self.assertRaises(ValueError, self._makeOneWithMap, app=None)
+
+
     def test_ctor_start_true(self):
         inst = self._makeOneWithMap(_start=True)
         self.assertEqual(inst.accepting, True)
         self.assertEqual(inst.socket.listened, 1024)
 
     def test_ctor_makes_dispatcher(self):
-        inst = self._makeOne(None, _start=False, map={})
+        inst = self._makeOne(_start=False, map={})
         self.assertEqual(inst.task_dispatcher.__class__.__name__,
                          'ThreadedTaskDispatcher')
 
@@ -198,7 +204,7 @@ if hasattr(socket, 'AF_UNIX'):
         def _makeOne(self, _start=True, _sock=None):
             from waitress.server import create_server
             return create_server(
-                None,
+                dummy_app,
                 map={},
                 _start=_start,
                 _sock=_sock,