should.not_have.key(...) not working properly

[chris922]

In the examples the following line is given, but it asserts to a failure using grappa 0.1.10:

{'bar': True} | should.not_have.key('foo')

See https://grappa.readthedocs.io/en/latest/operators.html#keys

The following error will be shown:

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
...\Python37\lib\site-packages\grappa\test.py:208: in __ror__
    return self.__overload__(value)
...\Python37\lib\site-packages\grappa\test.py:196: in __overload__
    return self.__call__(subject, overload=True)
...\Python37\lib\site-packages\grappa\test.py:73: in __call__
    return self._trigger() if overload else Test(subject)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <grappa.test.Test object at 0x00000230CAC56F60>

    def _trigger(self):
        """
        Trigger assertions in the current test engine.
    
        Raises:
            AssertionError: in case of assertion error.
            Exception: in case of any other assertion error.
        """
        log.debug('[test] trigger with context: {}'.format(self._ctx))
    
        try:
            err = self._engine.run(self._ctx)
        except Exception as _err:
            err = _err
        finally:
            # Important: reset engine state to defaults
            self._engine.reset()
            self._root._engine.reset()
    
        # If error is present, raise it!
        if err:
>           raise err
E           AssertionError: Oops! Something went wrong!
E           
E             The following assertion was not satisfied
E               subject "{'bar': True}" should not have key "foo"
E           
E             Where
E               File "...", line 11, in test_grappa_issue
E           
E               11| >     {'bar': True} | should.not_have.key('foo')
E               12|   

...\Python37\lib\site-packages\grappa\test.py:113: AssertionError

(I removed some lines of our code, so don't be confused about the line numbering)

[AndreiBarsan]

Can confirm, this check is buggy in 0.1.12!