Expose streaming conversion utility methods

[stephentoub]

We're already exposing the non-streaming response conversions. Expose the streaming ones as well.

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull Request Overview

This PR exposes streaming conversion utility methods for both OpenAI Chat and Responses APIs, mirroring the existing non-streaming conversion methods. The changes primarily add public extension methods to convert streaming OpenAI responses to Microsoft.Extensions.AI types.

• Adds AsChatResponseUpdatesAsync methods to both chat and responses extension classes
• Updates existing conversion methods to accept optional ChatOptions parameters
• Modifies visibility of internal streaming conversion methods to support the new public APIs

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
MicrosoftExtensionsAIChatExtensions.cs	Adds streaming chat completion conversion method and updates existing method signatures
MicrosoftExtensionsAIResponsesExtensions.cs	Adds streaming response conversion method and updates existing method signatures
OpenAIChatClient.cs	Changes visibility of streaming conversion method from private to internal
OpenAIResponsesChatClient.cs	Refactors streaming logic and changes method visibility to support new public APIs
OpenAIConversionTests.cs	Adds comprehensive tests for the new streaming conversion methods

Comments suppressed due to low confidence (2)

test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIConversionTests.cs:288

• The test method AsChatResponse_ConvertsOpenAIResponse only validates null argument handling but doesn't test the actual conversion logic due to OpenAI library limitations. Consider using mocking or test doubles to provide meaningful test coverage.

        // The OpenAI library currently doesn't provide any way to create an OpenAIResponse instance,

test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIConversionTests.cs:297

• The test method AsChatResponseUpdatesAsync_ConvertsOpenAIStreamingResponseUpdates only validates null argument handling but doesn't test the actual streaming conversion logic. Consider using mocking or test doubles to provide comprehensive test coverage for the streaming functionality.

        // The OpenAI library currently doesn't provide any way to create a StreamingResponseUpdate instance,