test: add responses api more cases

[bzp2010]

Summary by CodeRabbit

• Tests
  • Enhanced test coverage for response handling with additional scenarios covering event ordering, metadata persistence, replay behavior, input validation, streaming operations, and error handling.

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: fd40fd3b-f188-43eb-892e-03290281d853

📥 Commits

Reviewing files that changed from the base of the PR and between cc43c0c and 1d6ab42.

📒 Files selected for processing (1)

• tests/proxy/responses.test.ts

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📝 Walkthrough

Walkthrough

This PR extends the /v1/responses proxy route test suite with comprehensive end-to-end assertions covering streaming behavior, response storage and replay via previous_response_id, input validation, mixed output types, and error handling during bridge failures. Two older generic tests are removed.

Changes

Proxy /v1/responses endpoint test suite

Layer / File(s)	Summary
Baseline streaming and response transformation tests/proxy/responses.test.ts	New test validates exact SSE event ordering for text responses, verifies response/output ID rewriting to aresp_ pattern, and confirms terminal usage token totals.
Input validation and early rejection tests/proxy/responses.test.ts	New test rejects /v1/responses requests containing input_image entries with only file_id, returning invalid_request_error before upstream dispatch.
Storage and response replay behavior tests/proxy/responses.test.ts	Two new tests verify that store: true persists metadata and enables previous_response_id replay with merged message history; store: false blocks replay with previous_response_not_found error.
Mixed output item streaming tests/proxy/responses.test.ts	New test validates correct streaming of combined message and function-call outputs, verifies output_item.added events, and confirms function-call argument reconstruction.
Bridge failure and error streaming tests/proxy/responses.test.ts	New test simulates mid-stream bridge failure, asserting error event emission, absence of response.completed, and error message containing choice index.
Test suite consolidation tests/proxy/responses.test.ts	Removes two older generic tests for previous_response_id replay wiring and validation, consolidating their assertions into the new specific test cases.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

🚥 Pre-merge checks | ✅ 5 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
E2e Test Quality Review	⚠️ Warning	JSON.parse calls (lines 224, 496, 497, 562) lack error handling. No try-catch blocks or validation. Violates requirement to check all return values for errors.	Wrap JSON.parse in try-catch. Alternatively, validate event.data is defined and valid JSON before parsing. Add defensive assertions before type conversions.

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'test: add responses api more cases' is directly related to the changeset, which adds comprehensive test cases to the responses API test suite.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Security Check	✅ Passed	Test-only file with mock services. All credentials are test values. No sensitive data logging. Authorization, validation and error handling properly tested. No security issues found.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch bzp/test-responses-more-cases

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