[bug] unknown categories are not handled by an error

[karlcow]

@api.route('/issues/search/<issue_category>')
in https://github.com/webcompat/webcompat.com/blob/master/webcompat/api/endpoints.py#L194-L213

We deal with category list and if not know we say new but if none of that we return something without being defined in the first place, which creates the error message:

127.0.0.1 - - [10/Aug/2015 16:51:46] "GET /api/issues/search/foobar HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/karl/.virtualenvs/webcompatcom/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/karl/code/webcompat.com/webcompat/api/endpoints.py", line 213, in get_category_from_search
    return get_search_results(query_string, params)
UnboundLocalError: local variable 'query_string' referenced before assignment

ooops, my bad.

[karlcow]

Probably could use http://flask.pocoo.org/docs/0.10/api/#flask.Blueprint.app_errorhandler

[karlcow]

food for thoughts from http://blog.luisrei.com/articles/flaskrest.html

@app.errorhandler(404)
def not_found(error=None):
    message = {
            'status': 404,
            'message': 'Not Found: ' + request.url,
    }
    resp = jsonify(message)
    resp.status_code = 404

    return resp

@app.route('/users/<userid>', methods = ['GET'])
def api_users(userid):
    users = {'1':'john', '2':'steve', '3':'bill'}

    if userid in users:
        return jsonify({userid:users[userid]})
    else:
        return not_found()

[miketaylr]

@karlcow the not_found solution looks good.

[karlcow]

And my comment is on the wrong bug. 👊

[karlcow]

Once the #676 PR is merged, I will fix #667