Exception handling in aiohttp

[SpudInNZ]

Description

I am trying to figure out how to add an exception handling method to Connexion when using the aiohttp web server. The docs at https://connexion.readthedocs.io/en/latest/exceptions.html#default-exception-handling talk of add_error_handler, but it seems this is only available for Flask?

Expected behaviour

I expect that ProblemExceptions raised by request validation can be handled by the server, so a 400 error can be returned to the client when an incorrectly formatted HTTP request is received for example.

Actual behaviour

ProblemExceptions raised are not handled, and therefore a 500 error is returned to the client when a badly formatted HTTP request is made.

Steps to reproduce

1. Define GET request in Swagger spec, for example GET /accounts
2. Enable request validation in server startup, e.g.

cnx_app.add_api('swagger.yaml',
                    pass_context_arg_name="request",
                    validate_responses=True,
                   strict_validation=True)

3. Make request with unexpected parameter, e.g. GET /accounts?someUnexpectedArg=1
4. Server returns 500 error, as no exception handler is installed that can catch the ProblemException that gets raised.

Additional info:

Python version 3.7.1
Connexion version 2.0.2

[SpudInNZ]

Any thoughts on this @dtkav ?

[dtkav]

sorry, I'm very unfamiliar with aiohttp.

…

On Wed, Mar 27, 2019, 9:32 AM Ian Bevan ***@***.***> wrote: Any thoughts on this @dtkav <https://github.com/dtkav> ? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#898 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAlPSdFfoSXDGyCf3V-_4yszKFjMkwGzks5vap_6gaJpZM4bfze_> .

[cognifloyd]

In order to add error handling in aiohttp, you need to add a middleware that catches the exception.

Related: #952, #955

In both of these PRs, a middleware handles problem exceptions.
In #952, all exceptions are turned into Problems.

[cognifloyd]

Both #952 and #955 have been merged. @SpudInNZ can you try a newer release and see if that resolves your issue?