Check if the model param is valid for moderations endpoint

[MunarYesen]

Currently there are only two models available for OpenAI /moderations endpoint, which are text-moderation-stable and text-moderation-latest. In the official python library openai-python. The method Moderation will check if the model param is in VALID_MODEL_NAMES and returns an error when it's not.

 def _prepare_create(cls, input, model, api_key):
        if model is not None and model not in cls.VALID_MODEL_NAMES:
            raise ValueError(
                f"The parameter model should be chosen from {cls.VALID_MODEL_NAMES} "
                f"and it is default to be None."
            )

        instance = cls(api_key=api_key)
        params = {"input": input}
        if model is not None:
            params["model"] = model
        return instance, params

It would be great if we can add similar checks before passing the request to /v1/moderations endpoint.

[codecov]

Codecov Report

Merging #437 (1b8d84d) into master (f028c28) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head 1b8d84d differs from pull request most recent head 1e82071. Consider uploading reports for the commit 1e82071 to get more accurate results

@@            Coverage Diff             @@
##           master     #437      +/-   ##
==========================================
+ Coverage   97.02%   97.03%   +0.01%     
==========================================
  Files          17       17              
  Lines         705      709       +4     
==========================================
+ Hits          684      688       +4     
  Misses         15       15              
  Partials        6        6              

Impacted Files	Coverage Δ
moderation.go	100.00% <100.00%> (ø)

[vvatanabe]

@MunaerYesiyan Thanks for PR! How about trying to write exhaustive tests for both valid and invalid models in table driven tests?

[MunarYesen]

Included valid and invalid model for moderation unit testing.
e579559

[vvatanabe]

Confirmed not supported just in case. 👍

$ curl https://api.openai.com/v1/moderations \
                    -H "Content-Type: application/json" \
                    -H "Authorization: Bearer $OPENAI_API_KEY" \
                    -d '{
                  "input": "I want to kill them.", "model": "text-moderation-001"
                }'
{

  "error": {
    "message": "Invalid value for 'model' = text-moderation-001. Please check the OpenAI documentation and try again.",
    "type": "invalid_request_error",
    "param": "model",
    "code": null
  }
}

[MunarYesen]

Confirmed not supported just in case. 👍

$ curl https://api.openai.com/v1/moderations \
                    -H "Content-Type: application/json" \
                    -H "Authorization: Bearer $OPENAI_API_KEY" \
                    -d '{
                  "input": "I want to kill them.", "model": "text-moderation-001"
                }'
{

  "error": {
    "message": "Invalid value for 'model' = text-moderation-001. Please check the OpenAI documentation and try again.",
    "type": "invalid_request_error",
    "param": "model",
    "code": null
  }
}

And it's kinda confusing as the official document uses text-moderation-005 in the response example

[vvatanabe]

@MunaerYesiyan I would like you to add a comment indicating that this constant is deprecated.

[MunarYesen]

Deprecating the text-moderation-001 model in moderation.go e579559

[vvatanabe]

@MunaerYesiyan Thanks for the pull request!