Fix issue with posting with no content

[jas32096]

Check if there is no content before aborting the request.

This fixes issues with posts to endpoints that have no parameters i.e.

@routes.ItemRoute.POST('/mark_read')
    def mark_read(self, move_task) -> fields.DateTimeString():
        move_task.mark_read()
        return move_task.seen_at

Without this fix, you'd have one of two issues:

>> http POST :5000/v2/move_tasks/667/mark_read 'Authorization: Bearer '(cat mtoken) 'Content-type: application/json'
HTTP/1.0 400 BAD REQUEST
Content-Length: 111
Content-Type: application/json
Date: Tue, 16 May 2017 19:57:03 GMT
Server: Werkzeug/0.12.1 Python/3.6.1

{
    "message": "Failed to decode JSON object: Expecting value: line 1 column 1 (char 0)",
    "status": 400
}

>> http POST :5000/v2/move_tasks/667/mark_read 'Authorization: Bearer '(cat mtoken)
HTTP/1.0 415 UNSUPPORTED MEDIA TYPE
Content-Length: 60
Content-Type: application/json
Date: Tue, 16 May 2017 19:57:09 GMT
Server: Werkzeug/0.12.1 Python/3.6.1

{
    "message": "Unsupported Media Type",
    "status": 415
}

[coveralls]

Coverage remained the same at 88.901% when pulling 6201adf on jas32096:master into 88b9352 on biosustain:master.

[Alain1405]

Related to #94

[lyschoening]

I believe data and request.mimetype != 'application/json' is always False. request.get_json() will always return None if the mimetype is not 'application/json' so RequestMustBeJSON never gets raised.

The check that should be made instead is if data is required, e.g. self.fields is not empty, require a JSON request otherwise allow an empty request.

if request.method in ('POST', 'PATCH', 'PUT', 'DELETE'):		
    if self.fields and request.mimetype != 'application/json':		
        raise RequestMustBeJSON()

This could be moved back into the top of the function.

A unit test should be added to make sure.

[coveralls]

Coverage remained the same at 88.901% when pulling c779367 on jas32096:master into 88b9352 on biosustain:master.

[coveralls]

Coverage remained the same at 88.901% when pulling c779367 on jas32096:master into 88b9352 on biosustain:master.

[coveralls]

Coverage decreased (-0.3%) to 88.569% when pulling 4cdcfbc on jas32096:master into 88b9352 on biosustain:master.

[jas32096]

apparently my test doesn't work in python 2

[coveralls]

Coverage increased (+0.1%) to 89.012% when pulling 1644d36 on jas32096:master into 88b9352 on biosustain:master.

[lyschoening]

Is this not something that can be tested with the regular test client?

[jas32096]

@lyschoening Not without creating an entire test app, which seems frivolous. The Flask test client is better suited for Flask apps, then extensions.