make_app() now uses the debugger param in DebugMiddleware()

Setting app.debugger in setup.py now takes proper effect.
A warning is issued if the entry point is not callable.

Change-Id: I58a860b8ef0e1cb956b4554071275c024a1949d2
Closes-Bug: #1449573

docs/source/development.rst

@@ -29,11 +29,24 @@ browser for easy debugging:
 
 To further aid in debugging, the middleware includes the ability to repeat the
 offending request, automatically inserting a breakpoint, and dropping your
-console into the Python debugger, ``pdb``:
+console into the Python debugger, ``pdb.post_mortem``:
 
 .. figure:: debug-middleware-2.png
    :alt: Pecan debug middleware request debugger. 
 
+You can also use any debugger with a suitable ``post_mortem`` entry point.
+For example, to use the `PuDB Debugger <http://pypi.python.org/pypi/pudb>`_,
+set ``debugger`` like so::
+
+    import pudb
+
+    app = {
+        ...
+        'debug': True,
+        'debugger': pudb.post_mortem,
+        ...
+    }
+
 .. seealso::
 
   Refer to the `pdb documentation

pecan/__init__.py

@@ -4,19 +4,16 @@ from .core import (
 )
 from .decorators import expose
 from .hooks import RequestViewerHook
-from .middleware.debug import DebugMiddleware
-from .middleware.errordocument import ErrorDocumentMiddleware
-from .middleware.recursive import RecursiveMiddleware
-from .middleware.static import StaticFileMiddleware
-
 from .configuration import set_config, Config
 from .configuration import _runtime_conf as conf
+from . import middleware
 
 try:
     from logging.config import dictConfig as load_logging_config
 except ImportError:
     from logutils.dictconfig import dictConfig as load_logging_config  # noqa
 
+import six
 import warnings
 
 
@@ -40,6 +37,8 @@ def make_app(root, **kw):
                         debug mode is set.
     :param debug: A flag to enable debug mode.  This enables the debug
                   middleware and serving static files.
+    :param debugger: A callable to start debugging, defaulting to the Python
+                     debugger entry point ``pdb.post_mortem``.
     :param wrap_app: A function or middleware class to wrap the Pecan app.
                      This must either be a wsgi middleware class or a
                      function that returns a wsgi application. This wrapper
@@ -90,19 +89,28 @@ def make_app(root, **kw):
     # Configuration for serving custom error messages
     errors = kw.get('errors', getattr(conf.app, 'errors', {}))
     if errors:
-        app = ErrorDocumentMiddleware(app, errors)
+        app = middleware.errordocument.ErrorDocumentMiddleware(app, errors)
 
     # Included for internal redirect support
-    app = RecursiveMiddleware(app)
+    app = middleware.recursive.RecursiveMiddleware(app)
 
     # When in debug mode, load our exception dumping middleware
     static_root = kw.get('static_root', None)
     if debug:
-        app = DebugMiddleware(app)
+        debugger = kw.get('debugger', None)
+        debugger_kwargs = {}
+        if six.callable(debugger):
+            debugger_kwargs['debugger'] = debugger
+        elif debugger:
+            warnings.warn(
+                "`app.debugger` is not callable, ignoring",
+                RuntimeWarning
+            )
+        app = middleware.debug.DebugMiddleware(app, **debugger_kwargs)
 
         # Support for serving static files (for development convenience)
         if static_root:
-            app = StaticFileMiddleware(app, static_root)
+            app = middleware.static.StaticFileMiddleware(app, static_root)
 
     elif static_root:
         warnings.warn(

pecan/middleware/__init__.py

@@ -0,0 +1,4 @@
+from . import debug
+from . import errordocument
+from . import recursive
+from . import static

pecan/middleware/debug.py

@@ -253,7 +253,10 @@ class DebugMiddleware(object):
 
     To further aid in debugging, the middleware includes the ability to repeat
     the offending request, automatically inserting a breakpoint, and dropping
-    your console into the Python debugger, ``pdb``.
+    your console into the Python debugger, ``pdb.post_mortem``.
+
+    You can also use any debugger with a suitable ``post_mortem`` entry point
+    such as the `PuDB Debugger <http://pypi.python.org/pypi/pudb>`_,
 
     For more information, refer to the  `documentation for pdb
     <http://docs.python.org/library/pdb.html>`_ available on the Python
@@ -261,7 +264,7 @@ class DebugMiddleware(object):
 
     :param app: the application to wrap.
     :param debugger: a callable to start debugging, defaulting to the Python
-                     debugger, ``pdb``.
+                     debugger entry point ``pdb.post_mortem``.
     """
 
     def __init__(self, app, debugger=pdb.post_mortem):

pecan/tests/test_base.py

@@ -5,6 +5,7 @@ import warnings
 
 import webob
 from webob.exc import HTTPNotFound
+import mock
 from webtest import TestApp
 import six
 from six import b as b_
@@ -1616,6 +1617,41 @@ class TestNonCanonical(PecanTestCase):
         assert len(wrapped_apps) == 1
 
 
+class TestDebugging(PecanTestCase):
+    def test_debugger_setup(self):
+        class RootController(object):
+            pass
+
+        def debugger():
+            pass
+
+        app_conf = dict(
+            debug=True,
+            debugger=debugger
+        )
+        with mock.patch('pecan.middleware.debug.DebugMiddleware') \
+                as patched_debug_middleware:
+            app = make_app(RootController(), **app_conf)
+            args, kwargs = patched_debug_middleware.call_args
+            assert kwargs.get('debugger') == debugger
+
+    def test_invalid_debugger_setup(self):
+        class RootController(object):
+            pass
+
+        debugger = 'not_a_valid_entry_point'
+
+        app_conf = dict(
+            debug=True,
+            debugger=debugger
+        )
+        with mock.patch('pecan.middleware.debug.DebugMiddleware') \
+                as patched_debug_middleware:
+            app = make_app(RootController(), **app_conf)
+            args, kwargs = patched_debug_middleware.call_args
+            assert kwargs.get('debugger') is None
+
+
 class TestLogging(PecanTestCase):
 
     def test_logging_setup(self):