Refactor APIs for Items

[kdokm]

As a developer I need to refactor the code using a more advanced framework So that I can have generated documentation automatically

Details and Assumptions

• Using Flask-RESTX and Swagger
• Refactor the /shopcarts/{user_id}/items and /shopcarts/{user_id}/items/{item_id} routes
• Make sure all of the proper error codes returned (~e.g. 400 for an invalid user_id or item_id meaning not a non-negative integer, NOT 404~) [EDIT: prof said default 404 for those is the right thing to do so switch back to /shopcarts/\<int:user_id>] :(
• After refactoring use flask routes to list all routes, make sure there are no static gets or other routes not specified by our API explicitly.

• [UPDATE] Can delete MOST of (probably not all) error_handler.py when this is done since Flask_RESTX will handle errors automatically

  Acceptance Criteria

  Given we have refactored the above routes
  When we run nosetests and behave on the tests we had previously written on these routes
  Then all tests pass

[TimothyXu]

can put swagger tags (for auto-generating docs0 in a different story if need be

[TimothyXu]

Copying my comment in the GitHub PR for bookkeeping purposes. Most of the work is done which is great! Refactoring is fine. But 3 issues to deal with:

1. As prof said in our slack channel, A 400_BAD_REQUEST is reserved for the payload. Not the path. so we need to change all the urls back to int:shopcart_id etc. and not check for them manually. And when we try to call e.g. /shopcarts/wrongid we should get the default 404 from Flask and that's fine.
2. Once this is done we should also delete most of error_handlers.py so they don't impact our nosetests coverage
3. Unless I'm understanding HTML incorrectly due to not knowing any front end, we need to get rid of the static get route at /static/path:filename.

[TimothyXu]

1 and 2 done, need to possibly do 3 (please someone who knows how websites work chime in lol)