Catch HTTP exceptions in Request.applicationfeature/wrapper-exceptions

3 files changed, 31 insertions, 3 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index f498b372..0a7f6dae 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,7 +4,8 @@ Werkzeug Changelog
 Version 0.14
 ------------
 
-Unreleased
+- HTTP execptions are now automatically caught by
+  ``Request.application``.
 
 
 Version 0.13
diff --git a/tests/test_wrappers.py b/tests/test_wrappers.py
index 2d68b784..33a39df7 100644
--- a/tests/test_wrappers.py
+++ b/tests/test_wrappers.py
@@ -21,7 +21,8 @@ from werkzeug._compat import iteritems
 from tests import strict_eq
 
 from werkzeug import wrappers
-from werkzeug.exceptions import SecurityError, RequestedRangeNotSatisfiable
+from werkzeug.exceptions import SecurityError, RequestedRangeNotSatisfiable, \
+    BadRequest
 from werkzeug.wsgi import LimitedStream, wrap_file
 from werkzeug.datastructures import MultiDict, ImmutableOrderedMultiDict, \
     ImmutableList, ImmutableTypeConversionDict, CharsetAccept, \
@@ -220,6 +221,24 @@ def test_stream_only_mixing():
     strict_eq(request.stream.read(), b'foo=blub+hehe')
 
 
+def test_request_application():
+    @wrappers.Request.application
+    def application(request):
+        return wrappers.Response('Hello World!')
+
+    @wrappers.Request.application
+    def failing_application(request):
+        raise BadRequest()
+
+    resp = wrappers.Response.from_app(application, create_environ())
+    assert resp.data == b'Hello World!'
+    assert resp.status_code == 200
+
+    resp = wrappers.Response.from_app(failing_application, create_environ())
+    assert b'Bad Request' in resp.data
+    assert resp.status_code == 400
+
+
 def test_base_response():
     # unicode
     response = wrappers.BaseResponse(u'öäü')
diff --git a/werkzeug/wrappers.py b/werkzeug/wrappers.py
index f89241dd..5e28bec9 100644
--- a/werkzeug/wrappers.py
+++ b/werkzeug/wrappers.py
@@ -288,6 +288,9 @@ class BaseRequest(object):
             def my_wsgi_app(request):
                 return Response('Hello World!')
 
+        As of Werkzeug 0.14 HTTP exceptions are automatically caught and
+        converted to responses instead of failing.
+
         :param f: the WSGI callable to decorate
         :return: a new WSGI callable
         """
@@ -296,10 +299,15 @@ class BaseRequest(object):
         #: the request.  The return value is then called with the latest
         #: two arguments.  This makes it possible to use this decorator for
         #: both methods and standalone WSGI functions.
+        from werkzeug.exceptions import HTTPException
         def application(*args):
             request = cls(args[-2])
             with request:
-                return f(*args[:-2] + (request,))(*args[-2:])
+                try:
+                    resp = f(*args[:-2] + (request,))
+                except HTTPException as e:
+                    resp = e.get_response(args[-2])
+                return resp(*args[-2:])
         return update_wrapper(application, f)
 
     def _get_file_stream(self, total_content_length, content_type, filename=None,