[ENG-1272] Only use `register_uri()` for multi-URL registration

[cslzchen]

Here is the piece of code for register_uri() and register_json_uri() as shown below.

def register_uri(self, method, uri, **options):
    if any(x.get('params') for x in options.get('responses', [])):
        raise ValueError('Cannot specify params in responses, call register multiple times.')
    params = options.pop('params', {})
    url = ImmutableFurl(uri, params=params)
    self.registry[(method, url)] = options.get('responses', options)

def register_json_uri(self, method, uri, **options):
    body = json.dumps(options.pop('body', None)).encode('utf-8')
    headers = {'Content-Type': 'application/json'}
    headers.update(options.pop('headers', {}))
    self.register_uri(method, uri, body=body, headers=headers, **options)

When multiple URLs are registered using the responses param, the extra header headers = {'Content-Type': 'application/json'} in register_json_uri() is not used by register_uri() at all. In fact, the body param is not used either and only the responses param takes effect. This sometimes confuses the developers when they think that register_json_uri() guarantees the Content-Type header to be added while it actually doesn't for the multi-URL registration case. This breaks tests with aiohttp3 where .json() requires a valid Content-Type header in the response all the time. Below is the proposed fix.

Given that multi-URL registration requires and only uses the raw response list, it doesn't make any sense to use register_json_uri(). The two things that register_json_uri()does for us is dumping the body and adding the header, both are redundant when we need to provide the raw responses anyway as shown below in the multi-URL scenario.

aiohttpretty.register_uri(
    'POST',
    create_tree_url,
    **{
        "responses": [
            {
                'body': json.dumps(crud_fixtures_1).encode('utf-8'),
                'status': 201,
                'headers': {'Content-Type': 'application/json'}
            },
            {
                'body': json.dumps(crud_fixtures_2).encode('utf-8'),
                'status': 201,
                'headers': {'Content-Type': 'application/json'}
            },
        ]
    }
)

Please add a docstr / comment that multi-URL registration should only use register_uri() and the developers must provide everything in the responses list. In addition, throw an error when register_json_uri() is called with responses param (i.e. the multi-URL registration case).

Here are the two related commits in the PR: Throw GitHub into the Oath Pit where the issue is discovered.

• Explicitly add the Content-Type header: e1ee3e
• Use register_uri() instead of register_json_uri(): 851578

[cslzchen]

Here is the ticket: ENG-1272.