Allow the specification to be specified as a URL.

[mjp4]

Changes proposed in this pull request:

• Allow a specification to be specified as a URL that is downloaded when the App runs. In combination with the existing mock features, this makes it a single command to run a mock server for any published API.

[perrystallings]

Do you have a few tests for this PR?

In particular I'm interested in how this would work for specs without defined operation ids.

For context, I could see this being awesome for mocking external API service during development or even as part of a testing pipeline so that you automatically get the default/example response combined with request validation.

[RobbeSneyders]

Thanks @mjp4,

I'm indeed wondering the same as @perrystallings. Another option would be to include this in the CLI instead, if that's the only place where it would be useful.

[mjp4]

Thanks both, I've added a test.

I don't have an immediate proposal for handling APIs without Operation IDs, the ones I'm interested in all do.

As it stands, and especially combined with #1874 and #1870, it has the potential to provide useful dummy output in many situations.

I was also thinking of submitting a PR for a resolver that maps arbitrary Operation IDs to functions without making assumptions about module structure. Something like:

class DictResolver(connexion.Resolver):
    def __init__(self, handler_dict):
        def function_resolver(operation_id):
            function = handler_dict.get(operation_id)
            if function is not None:
                return function
            msg = f'Cannot resolve operationId "{operation_id}"! Supported operations: {list(handler_dict.keys())}'
            raise ValueError(msg)

        self.function_resolver = function_resolver

OPERATIONS = {
    "OperationOne": lambda: ("Body Text", 200)
}

resolver = DictResolver(OPERATIONS),

[coveralls]

coverage: 94.306% (+0.09%) from 94.214%
when pulling c19743e on mjp4:allow-url-spec
into 3e64fe4 on spec-first:main.

[RobbeSneyders]

As it stands, and especially combined with #1874 and #1870, it has the potential to provide useful dummy output in many situations.

Really appreciate the effort across these PRs 👍

I was also thinking of submitting a PR for a resolver that maps arbitrary Operation IDs to functions without making assumptions about module structure.

Happy to accept it if you can fit it cleanly in the current Resolver interface.

[RobbeSneyders]

Could we reuse the code we already use to resolve remote references?

connexion/connexion/json_schema.py

Lines 56 to 62 in 5de6dcc

	def __call__(self, uri):
	response = requests.get(uri)
	response.raise_for_status()
	data = io.StringIO(response.text)
	with contextlib.closing(data) as fh:
	return yaml.load(fh, ExtendedSafeLoader)

I like that it raises a clear error for non-successful requests and doesn't use a tempfile.

[RobbeSneyders]

Can you add in the docstrings that this can be a URL? The docstring is repeated in a couple of places across the code base, so would be good to do a find and replace.

Probably also good to explicitly mention this in the CLI docs.

[mjp4]

@RobbeSneyders I think this is ready to go in?

[RobbeSneyders]

Looks good indeed, thanks @mjp4!