Only catch TypeError/ValueError for object lookups

[rpkilby]

Fixes #6025. Basically, get_object() should handle the type/value error from .get() by reraising as a more specific exception type.

cc @tomchristie, @tveastman

[blueyed]

Needs a test though (https://codecov.io/gh/encode/django-rest-framework/pull/6028/diff).

[lovelydinosaur]

Neat route around, yup.

[lovelydinosaur]

I think this could have a clearer docstring. Mention that we use it to indicate when invalid values are passed to ‘queryset.get()’.

[rpkilby]

Are the new docstrings more clear? Generally, these exceptions will only be caught internally, so it should be fine?

[rpkilby]

Thanks @blueyed - test added.

[blueyed]

@rpkilby
Not really covered still: https://codecov.io/gh/encode/django-rest-framework/pull/6028/diff.

See #6050 for making this more accessible via Github's status API - i.e. it would show up with "Show all checks".

[rpkilby]

The updated tests should sufficiently cover the changeset.

[blueyed]

What about the following to please coverage? (used elsewhere already)

diff --git i/tests/test_relations.py w/tests/test_relations.py
index 3c76f009..9326b565 100644
--- i/tests/test_relations.py
+++ w/tests/test_relations.py
@@ -200,7 +200,7 @@ def test_hyperlinked_related_lookup_does_not_exist(self):
     def test_hyperlinked_related_internal_type_error(self):
         class Field(serializers.HyperlinkedRelatedField):
             def get_object(self, incorrect, signature):
-                pass
+                raise NotImplementedError()  # pragma: no cover
 
         field = Field(view_name='example', queryset=self.queryset)
         with pytest.raises(TypeError):

[rpkilby]

Makes sense - raising NotImplementedError is more appropriate than just silently passing. I've also added NotImplementedError to the coverage line exclusions.

[rpkilby]

btw, merged the setup.cfg changes in another PR.

Changes made