[BUG] ImageSize changed to Internal after update to tsp 49

[m-nash]

This diff here shows ImageSize changed to internal after updating to tsp 49 even though it is used.

https://github.com/Azure/azure-sdk-for-net/pull/39275/files#diff-b3c91385d402437b3802172c456a65b99264b90c4049dcd88f37acd4dc1b7843R14

I have fixed this with manual code for now but we should investigate / fix this.

[archerzz]

@m-nash After the investigation, I think that change is expected. I guess there used to be a bug in accessibility determination in TCGC, which has been fixed in the latest version.

Check the current OpenAI definition: https://github.com/Azure/azure-rest-api-specs/blob/4c38cb9966cd6afbb03c7e9b14997720a728baee/specification/cognitiveservices/OpenAI.Inference/client.tsp#L17C1-L18C39

ImageGenerationOptions is internal by definition, since it's only used by beginAzureBatchImageGeneration which is internal. As you can see in the definition, @@include is added to intentionally make it public.

However, that doesn't work in C#, because generator doesn't support @@include. So ImageGenerationOptions should be internal, so is its child ImageSize (see here).

In OpenAI .NET SDK, we wrote custom codes to make ImageGenerationOptions public. But that won't impact the accessibility of ImageSize.

So, in your PR, you added a snippet of custom codes to make ImageSize public, which is actually expected.

I think the better way to fix it is to update the OpenAI typespec definitions to adopt the new accessibility decorators.

[archerzz]

The correct tsp declaration of ImageSize will be fixed in Azure/azure-rest-api-specs#25856

[pshao25]

Already fixed in azure-sdk-for-net.