fix(types): allow missing name on function_call_arguments.done events

[Solaris-star]

Summary

• Live Responses streaming can emit response.function_call_arguments.done without a name field.
• The generated model required name: str, so strict ResponseStreamEvent union validation failed (missing: name) and typed access was misleading after lenient construction.
• Make name optional on the responses + beta responses done events; keep present values working.
• Add unit coverage for missing/present name and for union validation.

Fixes #3472

Test plan

• pytest tests/test_response_function_call_arguments_done_event.py -o addopts= → 4 passed
• CI full suite
• Note: types are Stainless-generated; this hand-edit may need to land in the upstream OpenAPI/spec so future regenerations keep the optional field.

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Use Pydantic-v1-compatible validation in tests

In the pydantic-v1 CI session (noxfile.py installs pydantic<2 and runs the full pytest suite), this new test file fails before exercising the fix: under Pydantic v1 these models do not expose model_validate, and the later union test also calls pydantic.TypeAdapter, which is v2-only. Using the repository's compatibility helpers (or otherwise gating the v2-only union assertion) keeps the tests passing for the supported pydantic>=1.9.0,<3 range.

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[amirhosseinghanipour]

Nice, this fixes #3472. name going missing on response.function_call_arguments.done in the wild was silently swallowed by the lenient-construct fallback before, so good catch making it Optional[str] instead of pretending it's always there. A couple of things I'd flag before merging though:

• Both of these are marked # File generated from our OpenAPI spec by Stainless at the top. Hand-editing them fixes the symptom locally, but the next spec sync will just stomp this change and reintroduce name: str unless the underlying OpenAPI spec gets updated too. Might be worth pinging someone on the API/spec side so this doesn't quietly regress next release.
• Same question the issue itself raised: is name actually supposed to be absent on this event, or is that a spec/API drift bug that should get fixed upstream instead? If the field is genuinely useful (correlating without going back to output_item.added), it might be worth pushing for the API to just emit it consistently rather than accepting it can vanish.
• Test coverage is solid. Appreciate covering the union validation path too, not just the model in isolation, since that's literally what broke for OP.

[jbeckwith-oai]

Two blockers before this can land:

1. The new test module breaks the supported Pydantic v1 test matrix. Under pydantic==1.10.26, all four tests fail because BaseModel.model_validate and pydantic.TypeAdapter are v2-only APIs. The production model change itself validates correctly on v1; please express these tests through the repository compatibility helpers (for example openai._compat.model_parse for models and openai._models.validate_type for the union) so the behavior is exercised on both supported Pydantic generations rather than skipping v1.

2. The normal lint gate is red. ./scripts/lint reports an unsorted import block and an unused pytest import in tests/test_response_function_call_arguments_done_event.py; ruff format --check also says that file needs formatting. Please run the repo formatter/linter and commit the result.