Unit testing OpenAI dotnet classes - internal + sealed

[gjz22]

We use OpenAI chat completion service, but OpenAIChatMessageContent is sealed and has an internal method constructor. Are there any ways people are unit testing classes that use this object?

[sophialagerkranspandey]

We recommend checking out details on Unit Testing here: https://devblogs.microsoft.com/semantic-kernel/unit-testing-with-semantic-kernel/

[dluc]

@gjz22 OpenAIChatCompletionService methods return these types, which have a public ctor

• ChatMessageContent
• StreamingChatMessageContent
• TextContent
• StreamingTextContent

That should allow to mock SK responses.

[gjz22]

Thank you for the details! My understanding is that in order to use chat completion service function calling you must downcast ChatMessageContent to OpenAIChatMessageContent, which is a sealed class with an internal constructor making it effectively not able to be mocked.

Newer versions of semantic kernel have FunctionCallContent, which probably I can use to mock the output to get the function call content. In my tests I'd need to be able to mock a function / plugin + arguments for the call for my use case, which don't seem to be in the link shared above.

Thanks!