[BUG] Backward compatibility issues due to positional args

[nathaliellenaa]

What is the bug?

The code generation process is incorrectly adding new arguments to function signatures, causing backwards compatibility issues. Specifically, new arguments are not being added as the last parameter in function signatures. This breaks existing code that uses positional arguments, as the order of arguments matters for positional calls.

Example: The search_shards method now expects a body parameter, but it's not added as the last argument, causing test failures. See this PR for reference.

How can one reproduce the bug?

Run the test suite, specifically: test_opensearchpy/test_server/test_rest_api_spec.py::test_rest_api_spec[OpenSearch-main/rest-api-spec/src/main/resources/rest-api-spec/test/search_shards/20_slice[0]]
Observe the following error: TypeError: OpenSearch.search_shards() got an unexpected keyword argument 'body'

What is the expected behavior?

New arguments (e.g. body) should be added as the last parameter in function signatures.
The method should support both positional and keyword argument calls:

Existing positional call (should still work):
client.search_shards('books', {})

New keyword call (should now be supported):
client.search_shards(index='books', params={}, body={})

What is your host/environment?

Operating system, version.

Do you have any screenshots?

If applicable, add screenshots to help explain your problem.

Do you have any additional context?

Add any other context about the problem.

[gkamat]

The error message noted above:

TypeError: OpenSearch.search_shards() got an unexpected keyword argument 'body'

is not calling out that the body argument is in the wrong position in the function prototype. Rather, it is indicating that an unexpected named/keyword argument was supplied in the function call, that is not present in the signature.

In other words, the error has nothing to do with positional parameters.

As a matter of fact, the search_shards() method in client/__init.py__ has the following signature, with no body argument.

    def search_shards(
        self,
        index: Any = None,
        params: Any = None,
        headers: Any = None,
    ) -> Any:

The API spec does not seem to indicate the presence of a request body for the search_shards API either. The spec is perhaps defining the pre-2.19 convention, so it is not clear what the PR above is referring to, and this is likely not an issue with the code generator.

On the other hand, the test being run, search_shards/20_slice, does supply a body argument, which appears to be the cause of the error.

Perhaps tests for version 2.19 have been added to exercise new search_shards features, that don't conform to the current API, and the intention is to update the API for OpenSearch v3.0.0. If that is the case, those tests should be skipped.

[gkamat]

Apparently, the offending tests were originally intended for v3.0.0, but are now running for 2.19 per change 6202ab08980. Opened this issue.

[nathaliellenaa]

Got it. Thanks for the explanation and opening the issue for this @gkamat