Make "json" property optionally callable

[malthe]

The requests library has a callable json attribute.

To make TestResponse.json "optionally callable", we use the following work-around:

class JsonResponseMixin(object):
    """
    Mixin with testing helper methods
    """

    @cached_property
    def json(self):
        """Return response data as a Python object.

        The data is deserialized using the JSON format.
        """

        # Note that during testing, this response class may already
        # provide a JSON property. We re-implement it here for
        # consistency.
        value = loads(self.data)

        # Adapt value to make it callable. Alas, the 'requests'
        # library changed its response class such that the JSON
        # property is callable.
        cls = type(value)
        return type(cls.__name__, (cls, ), {
            '__call__': lambda v: cls(v),
            '__module__': cls.__module__,
            '__reduce__': lambda v: (cls, (cls(v), )),
        })(value)

That is, you can call it or use it directly – because it's a dict whose callable returns the dict.

[jarus]

I can understand you wish to have the same API like requests but with this workaround there can be too much pitfalls. Maybe we can talk about a general change to a function instead a property.

[malthe]

It actually works really well (flawlessly) in practice. We use it in our system.

Note that in any case, this is a testing framework. It is not a library that's used in production.

-Malthe

On Wednesday, July 23, 2014, Christoph Heer [email protected] wrote:

I can understand you wish to have the same API like requests but with this workaround there can be too much pitfalls. Maybe we can talk about a general change to a function instead a property.

— Reply to this email directly or view it on GitHub https://github.com/jarus/flask-testing/issues/58#issuecomment-49888082.

[jarus]

It actually works really well (flawlessly) in practice. We use it in our system.

Okay, cool.

Note that in any case, this is a testing framework. It is not a library that's used in production.

Yes, sure but a testing framework/extension shouldn't break tests of users.

[malthe]

The testing framework should reflect the actual usage. If it does not, then it's broken. But if it does, then it's okay.

But I think perhaps it should be a switch that you can enable on the test class such as json_property = True.