Add Module.app_errorhandler, like Flask.errorhandler.

flask.py

@@ -612,6 +612,15 @@ def app_context_processor(self, f):
             .setdefault(None, []).append(f))
         return f
 
+    def app_errorhandler(self, code):
+        """Like :meth:`Flask.errorhandler` but for a module.  This
+        handler is used for all requests, even if outside of the module.
+        """
+        def decorator(f):
+            self._record(lambda s: s.app.errorhandler(code)(f))
+            return f
+        return decorator
+
     def _record(self, func):
         self._register_events.append(func)
 

tests/flask_tests.py

@@ -260,7 +260,7 @@ def error():
         assert rv.data == 'not found'
         rv = c.get('/error')
         assert rv.status_code == 500
-        assert 'internal server error' in rv.data
+        assert 'internal server error' == rv.data
 
     def test_response_creation(self):
         app = flask.Flask(__name__)
@@ -536,6 +536,30 @@ def index():
         app.register_module(admin, url_prefix='/admin')
         assert app.test_client().get('/admin/').data == '42'
 
+    def test_error_handling(self):
+        app = flask.Flask(__name__)
+        admin = flask.Module(__name__, 'admin')
+        @admin.app_errorhandler(404)
+        def not_found(e):
+            return 'not found', 404
+        @admin.app_errorhandler(500)
+        def internal_server_error(e):
+            return 'internal server error', 500
+        @admin.route('/')
+        def index():
+            flask.abort(404)
+        @admin.route('/error')
+        def error():
+            1 // 0
+        app.register_module(admin)
+        c = app.test_client()
+        rv = c.get('/')
+        assert rv.status_code == 404
+        assert rv.data == 'not found'
+        rv = c.get('/error')
+        assert rv.status_code == 500
+        assert 'internal server error' == rv.data
+
 
 class SendfileTestCase(unittest.TestCase):