Fix for Case Sensitivity Issue in Python Library When Retrieving Feature Flag Payload

[reihtw]

When trying to retrieve the feature flag payload, it is not possible to do so using uppercase characters because the code always converts the provided feature flag key to lowercase.

This issue occurs only in the Python library. I tried retrieving the payload using other languages, and it works normally.

[dmarticus]

Hi @reihtw, sorry for the delay in reviewing this, I was OOO for the last week.

I reproduced this issue locally and confirmed that your fix works. Thanks for the contribution! Do you mind adding a test to test/test_feature_flags.py that verifies this behavior? It couldn't hurt to encode these types of bugs into our tests. Something like this

    @mock.patch("posthog.client.decide")
    def test_boolean_feature_flag_payload_for_capitalized_feature_flags_decide(
        self, patch_decide
    ):
        patch_decide.return_value = {"featureFlagPayloads": {"PERSON-FLAG": 300}}
        self.assertEqual(
            self.client.get_feature_flag_payload(
                "PERSON-FLAG", "some-distinct-id", person_properties={"region": "USA"}
            ),
            300,
        )

        self.assertEqual(
            self.client.get_feature_flag_payload(
                "PERSON-FLAG",
                "some-distinct-id",
                match_value=True,
                person_properties={"region": "USA"},
            ),
            300,
        )
        self.assertEqual(patch_decide.call_count, 2)

and maybe another one for the local evaluation path is all we would need :)

Thank you!