[FEATURE] Generated tests for generated code

[VachaShah]

Coming from #511 (review), as @dblock suggested, we should have tests for all the generated code we are putting in, starting with some basic tests that are also generated.

[saimedhi]

I recommend using this Yaml test runner for integration tests. https://github.com/opensearch-project/opensearch-py/blob/main/test_opensearchpy/test_server/test_rest_api_spec.py

[VachaShah]

@saimedhi Can we generate some tests from this?

[saimedhi]

The YAML test runner generates tests based on the spec https://github.com/saimedhi/OpenSearch/tree/main/rest-api-spec/src/main/resources/rest-api-spec/test
These tests are stored temporarily and won't be saved. While I'm not certain if these tests can be displayed in clients, they are running and can be utilized.

[dblock]

I think some unit tests wouldn't hurt either.

[dblock]

@saimedhi Are we generating with the recent changes when a new API is added? If we do we can close this.

[saimedhi]

Currently tests are not generated. This needs to be done :)