Support generic mapping in builtin assertrepr compare

[DavideCanton]

What's the problem this feature will solve?

Having a nicely formatted assert when comparing mappings that are not subclass of dicts.

Describe the solution you'd like

I think it's enough to change the check in _compare_eq_any and similar that at the moment does isinstance(x, dict) to mapping, since it seems that _compare_eq_dict already supports mappings.

Alternative Solutions

At the moment, I just do assert dict(d1) == dict(d2)

Additional context

[RonnyPfannschmidt]

This will need nuance

There's multiple config/attrdict/box libraries that make this error prone

[CaselIT]

Making it opt-in in some way would also be fine if there are concerns about enabling it by default

[DavideCanton]

I can't see how this is error prone with mappings while it was already implemented for sequences:

class MySequence:
    def __init__(self, data):
        self.data = data

    def __getitem__(self, index):
        return self.data[index]

    def __len__(self):
        return len(self.data)

    def __repr__(self):
        return f"MySequence({self.data})"


def test_foo():
    assert MySequence([1, 2, 3]) == [1, 2, 4]

tests/foo_test.py::test_foo FAILED                                                                                                                                                                           [100%]

===================================================================================================== FAILURES =====================================================================================================
_____________________________________________________________________________________________________ test_foo _____________________________________________________________________________________________________

    def test_foo():
>       assert MySequence([1, 2, 3]) == [1, 2, 4]
E       assert MySequence([1, 2, 3]) == [1, 2, 4]
E         
E         Full diff:
E         + MySequence([1, 2, 3])
E         - [
E         -     1,
E         -     2,
E         -     4,
E         - ]

tests/foo_test.py:16: AssertionError
============================================================================================= short test summary info ==============================================================================================
FAILED tests/foo_test.py::test_foo - assert MySequence([1, 2, 3]) == [1, 2, 4]
================================================================================================ 1 failed in 0.07s =================================================================================================

[RonnyPfannschmidt]

Sequence is far easier than a number of mappings with extra behavior

That being said i ran a experiment and the issue is less severe than anticipated