Add FunctionInvokingChatClient.CurrentContext

[MackinnonBuck]

Allows AI functions to access the current FunctionInvokingChatClient.FunctionInvocationContext.

This can be used to access the chat history or terminate the function invocation loop.

Fixes#5705

Microsoft Reviewers: Open in CodeFlow

[stephentoub]

Thanks!

[Copilot]

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/FunctionInvokingChatClient.cs:670

• Ensure that CurrentContext is reset appropriately after the function invocation to avoid unintended side effects.

CurrentContext = context;

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[dotnet-comment-bot]

‼️Found issues‼️

Project	Coverage Type	Expected	Actual
Microsoft.Extensions.Caching.Hybrid	Line	86	77.82 🔻

🎉 Good job! The coverage increased 🎉
Update MinCodeCoverage in the project files.

Project	Expected	Actual
Microsoft.Extensions.AI	88	89

Full code coverage report: https://dev.azure.com/dnceng-public/public/_build/results?buildId=912643&view=codecoverage-tab

[dotnet-comment-bot]

‼️Found issues‼️

Project	Coverage Type	Expected	Actual
Microsoft.Extensions.Caching.Hybrid	Line	86	77.7 🔻

🎉 Good job! The coverage increased 🎉
Update MinCodeCoverage in the project files.

Project	Expected	Actual
Microsoft.Extensions.AI	88	89

Full code coverage report: https://dev.azure.com/dnceng-public/public/_build/results?buildId=912705&view=codecoverage-tab