fix: issues https://github.com/hugapi/hug/issues/911

hug/interface.py

@@ -932,8 +932,11 @@ def __call__(self, request, response, api_version=None, **kwargs):
                 )[::-1]:
                     if isinstance(exception, match_exception_type):
                         for potential_handler in exception_handlers:
-                            if not isinstance(exception, potential_handler.exclude):
-                                handler = potential_handler
+                            if hasattr(potential_handler, "exclude") and isinstance(exception, potential_handler.exclude):
+                                continue
+
+                            handler = potential_handler
+                            break
 
             if not handler:
                 raise exception

tests/test_exception_handler.py

@@ -0,0 +1,50 @@
+import hug
+import time
+
+base_error_message = "500 Internal Server Error"
+friendly_error_message = "Friendly error message"
+
+
+class BaseError(Exception):
+    code = 500
+    message = base_error_message
+
+    def __init__(self):
+        ...
+
+    def __str__(self):
+        return self.message
+
+
+class FriendlyError(BaseError):
+    message = friendly_error_message
+
+
+api = hug.API(__name__)
+
+
+# @hug.exception(UserError, api=api)
+def handler_friendly_error(request, response, exception):
+    # do something
+    response.status = hug.falcon.HTTP_200
+    data = dict(data=None, msg=exception.message, timestamp=time.time(), code=exception.code)
+    response.body = hug.output_format.json(data)
+
+
+def test_handler_direct_exception():
+    @hug.object.urls("/test", requires=())
+    class MyClass(object):
+        @hug.object.get()
+        def test(self):
+            raise FriendlyError()
+
+    api.http.add_exception_handler(FriendlyError, handler_friendly_error)
+    assert hug.test.get(api, "/test").data.get("msg", "") == friendly_error_message
+
+    # fix issues: https://github.com/hugapi/hug/issues/911
+    api.http.add_exception_handler(BaseError, handler_friendly_error)
+    assert hug.test.get(api, "/test").data.get("msg", "") == friendly_error_message
+
+
+if __name__ == "__main__":
+    test_handler_direct_exception()