Add post-mortem debugging.

CHANGES.txt

@@ -1,3 +1,9 @@
+After 0.6
+
+  - Add post-mortem debug middleware (egg:repoze.errorlog#pdbpm)
+
+  - Remove versions from dependencies.
+
 0.6
 
   - Get rid of find-link point to http://dist.repoze.org in setup.py.

README.txt

@@ -5,12 +5,9 @@ repoze.errorlog README
     This package implements a WSGI Middleware filter which intercepts
     exceptions and writes them to a Python 'logging' module channel
     (or the 'wsgi.errors' filehandle, if no channel is configured).
-
-  Installation
-
-    The simple way::
-
-      $ bin/easy_install --find-links=http://dist.repoze.org/ repoze.errorlog
+    It also allows the browsing of limited exception history via a
+    browser UI.  It also provides middleware that allows for
+    post-mortem debugging.
 
   Configuration
 
@@ -87,4 +84,15 @@ repoze.errorlog README
       url = construct_url(environ, path_info=path, 
                           querystring='entry=%s' % entry)
 
-
+  Post-Mortem Debugging
+
+    You will be dropped into Python's PDB post-mortem debugger if you
+    run your WSGI app in the foreground and use the
+    'egg:repoze.errorlog#pdbpm' entry point in your Paste
+    configuration, eg.::
+
+      [pipeline:main]
+      pipeline = egg:Paste#cgitb
+                 egg:repoze.errorlog#pdbpm
+                 myapp
+

repoze/errorlog/__init__.py

@@ -14,6 +14,7 @@
 
 from logging import getLogger
 import os
+import pdb
 import pprint
 import sys
 import traceback
@@ -175,3 +176,20 @@ def make_errorlog(app, global_conf, **local_conf):
             ignored_exceptions.append(ignored_exc)
     ignored_exceptions = tuple(ignored_exceptions)
     return ErrorLog(app, channel, keep, path, ignored_exceptions)
+
+# stolen partly from z3c.evalexception
+def PostMortemDebug(application):
+    """Middleware that catches exceptions and invokes pdb's
+    post-mortem debugging facility."""
+    def middleware(environ, start_response):
+        try:
+            return application(environ, start_response)
+        except:
+            pdb.post_mortem(sys.exc_info()[2])
+            raise
+
+    return middleware
+
+def make_post_mortem_debug(app, global_conf):
+    return PostMortemDebug(app)
+

repoze/errorlog/tests.py

@@ -177,6 +177,65 @@ def test_insert_error(self):
         self.assertEqual(elog.errors[0].__class__, Error)
         del exc_info
 
+class TestPDBPM(unittest.TestCase):
+    def _getFUT(self):
+        from repoze.errorlog import PostMortemDebug
+        return PostMortemDebug
+
+    def _makeOne(self, app):
+        f = self._getFUT()
+        return f(app)
+
+    def test_post_mortem_withexc(self):
+        app = DummyApplication(KeyError)
+        mw = self._makeOne(app)
+        fake_pdb = FakePDB()
+        try:
+            import repoze.errorlog
+            old_pdb = repoze.errorlog.pdb
+            repoze.errorlog.pdb = fake_pdb
+            environ = {}
+            self.assertRaises(KeyError, mw, environ, None)
+        finally:
+            repoze.errorlog.pdb = old_pdb
+        self.assertEqual(fake_pdb.called, True)
+
+    def test_post_mortem_noexc(self):
+        app = DummyApplication()
+        mw = self._makeOne(app)
+        fake_pdb = FakePDB()
+        try:
+            import repoze.errorlog
+            old_pdb = repoze.errorlog.pdb
+            repoze.errorlog.pdb = fake_pdb
+            environ = {}
+            result = mw(environ, None)
+        finally:
+            repoze.errorlog.pdb = old_pdb
+        self.assertEqual(fake_pdb.called, False)
+        self.assertEqual(result, ['hello world'])
+
+    def test_paste_constructor(self):
+        app = DummyApplication() 
+        from repoze.errorlog import make_post_mortem_debug
+        mw = make_post_mortem_debug(app, None)
+        fake_pdb = FakePDB()
+        try:
+            import repoze.errorlog
+            old_pdb = repoze.errorlog.pdb
+            repoze.errorlog.pdb = fake_pdb
+            environ = {}
+            result = mw(environ, None)
+        finally:
+            repoze.errorlog.pdb = old_pdb
+        self.assertEqual(fake_pdb.called, False)
+        self.assertEqual(result, ['hello world'])
+
+class FakePDB:
+    called = False
+    def post_mortem(self, *args):
+        self.called = True
+
 class DummyApplication:
     def __init__(self, exc=None):
         self.exc = exc

setup.py

@@ -47,19 +47,20 @@
       namespace_packages=['repoze'],
       zip_safe=False,
       tests_require = [
-           'meld3 >= 0.6.4',
-           'elementtree >= 1.2.6, < 1.2.7',
-           'Paste >= 1.5',
+           'meld3',
+           'elementtree',
+           'Paste',
            ],
       install_requires = [
-           'meld3 >= 0.6.4',
-           'elementtree >= 1.2.6, < 1.2.7',
-           'Paste >= 1.5',
+           'meld3',
+           'elementtree',
+           'Paste',
            ],
       test_suite="repoze.errorlog.tests",
       entry_points = """\
       [paste.filter_app_factory]
       errorlog = repoze.errorlog:make_errorlog
+      pdbpm = repoze.errorlog:make_post_mortem_debug
       """
       )