test: Add quality and features TCK tests for JSON-RPC

[lbobinski]

Description

This PR enhances the TCK test coverage for the JSON-RPC transport by enabling the 'quality' and 'features' categories in the CI workflow.

This change aligns with Phase 1 of the transport coverage plan outlined in @docs/plan_python_639.md, ensuring the robustness and feature completeness of the existing JSON-RPC implementation before introducing additional transports.

Key changes:

• Updated .github/workflows/run-tck.yaml to include test runs with --category quality and --category features for the jsonrpc transport.

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Partial fix for #639

[gemini-code-assist]

Summary of Changes

Hello @lbobinski, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the robustness and feature coverage of the JSON-RPC transport by implementing stricter data validation and improving the TCK agent's ability to process diverse message components. These changes directly contribute to the 'quality' and 'features' categories of the transport coverage plan. Additionally, it prepares the TCK agent for future transport expansions by configuring it to expose a REST endpoint.

Highlights

• Stricter Model Validation: Pydantic models derived from A2ABaseModel now forbid extra fields, enforcing stricter schema validation and improving data integrity.
• Enhanced Message Part Validation: The TCK agent now includes robust validation for user message parts, ensuring messages are not empty and only contain supported types like TextPart, FilePart, and DataPart, failing gracefully for unsupported parts.
• REST Transport Preparation in TCK Agent: The TCK agent has been updated to expose a new /a2a/rest endpoint using A2ARESTFastAPIApplication, laying the groundwork for future REST transport testing alongside the existing JSON-RPC.

Changelog

• src/a2a/_base.py
  • Added extra='forbid' to model_config in A2ABaseModel to enforce strict schema validation for all derived models.
• tck/sut_agent.py
  • Imported A2ARESTFastAPIApplication, FilePart, DataPart, InvalidParamsError, and ServerError to support new functionalities.
  • Implemented comprehensive validation for user_message.parts within the execute function, checking for empty messages and ensuring all parts are of known types (TextPart, FilePart, DataPart). Unsupported parts now trigger a failed task status.
  • Configured the TCK agent to serve a new /a2a/rest endpoint using A2ARESTFastAPIApplication, alongside the existing JSON-RPC endpoint, to enable future REST transport testing.

Ignored Files

• Ignored by pattern: .github/workflows/** (1)
  • .github/workflows/run-tck.yaml

Activity

• No specific activity (comments, reviews, etc.) has been provided for this pull request yet.

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[gemini-code-assist]

Code Review

This pull request enhances the TCK test coverage for JSON-RPC by enabling 'quality' and 'features' tests. To pass these new tests, changes have been made to improve robustness. This includes adding extra='forbid' to the base Pydantic model to disallow unknown fields, and adding validation logic for message parts in the SUT agent. The SUT agent is also updated to run a REST server alongside the JSON-RPC server. Overall, the changes are good and improve the quality of the test agent. I have a couple of minor suggestions for code cleanup and style.

[gemini-code-assist]

There's a minor indentation issue here. This line has an extra space at the beginning. Please correct it for code style consistency.

Suggested change

	actual_part = part.root
	actual_part = part.root

[gemini-code-assist]

The task_id and context_id fields are already present in the parent TaskStatusUpdateEvent object. Including them again in this nested Message object is redundant. Consider removing them to improve code clarity and avoid data duplication.