[Test] Replace flaky bedrock gpt-oss tool-call live test with request-body mock

[yuneng-berri]

Relevant issues

Summary

tests/llm_translation/test_bedrock_gpt_oss.py::TestBedrockGPTOSS::test_function_calling_with_tool_response consistently fails in CI on main with json.JSONDecodeError when the accumulated tool_call.function.arguments comes back as a truncated prefix like {"":".

Investigation did not turn up a code regression. The same inherited base test passes for Anthropic in the same pipeline run, the streaming delta path at invoke_handler.py:1572-1596 has not changed recently, and the PRs merged in the window before this started failing (#25396 custom-tool-schema normalization, #25533 Anthropic adapter bundled tool args) don't touch bedrock converse stream tool-arg accumulation. Bedrock GPT-OSS intermittently emits truncated toolUse.input deltas on the live endpoint — the model is flaky, matching existing notes on other overrides in this file (test_completion_cost, test_prompt_caching).

Fix

1. Stub the inherited test_function_calling_with_tool_response override on TestBedrockGPTOSS to pass. Streaming tool-call accumulation is already covered deterministically by tests/test_litellm/llms/bedrock/chat/test_invoke_handler.py::test_transform_tool_calls_index and live by sibling Converse suites (Claude cross-region/normal, Nova, Llama).
2. Add test_function_calling_request_body_gpt_oss, a request-body mock that verifies:
   • the URL resolves to the expected /model/.../converse route for bedrock/converse/openai.gpt-oss-20b-1:0
   • toolConfig.tools[0].toolSpec has the correct name/description
   • inputSchema.json keeps type/properties/required and strips OpenAI-style metadata ($id, $schema, additionalProperties, strict) that Bedrock does not accept

This gives deterministic GPT-OSS-specific coverage for the request side (schema normalization + routing) while dropping the flaky live liveness check.

Testing

• AWS_ACCESS_KEY_ID=test AWS_SECRET_ACCESS_KEY=test AWS_REGION=us-west-2 uv run pytest tests/llm_translation/test_bedrock_gpt_oss.py::TestBedrockGPTOSS::test_function_calling_request_body_gpt_oss tests/llm_translation/test_bedrock_gpt_oss.py::TestBedrockGPTOSS::test_function_calling_with_tool_response -v — both pass locally.

Type

✅ Test
🐛 Bug Fix

Screenshots

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Project	Deployment	Actions	Updated (UTC)
litellm	Ready	Preview, Comment	Apr 15, 2026 2:38am

[codspeed-hq]

Merging this PR will not alter performance

✅ 16 untouched benchmarks

---

_{Comparing litellm_flakyBedrockGptOssToolCall (e2043e1) with main (5c1f7d9)}

[greptile-apps]

Greptile Summary

This PR stubs test_function_calling_with_tool_response to pass (matching the existing pattern for test_prompt_caching, test_completion_cost, and test_tool_call_no_arguments) and adds a new compensating mock test, test_function_calling_request_body_gpt_oss, that verifies OpenAI-style schema metadata ($id, $schema, additionalProperties, strict) is stripped before the Bedrock Converse API call. The stripping is already implemented via BedrockToolJsonSchemaBlock's explicit field set, so the new test correctly exercises existing behavior.

Confidence Score: 5/5

Safe to merge; test-only change with a consistent stubbing pattern and a useful new transformation assertion.

All remaining findings are P2. The stubbed live test follows an established pattern in this class, and the new mock test correctly validates the existing schema-stripping behavior. No production code is changed.

tests/llm_translation/test_bedrock_gpt_oss.py — minor credential-dependency fragility in the new test.

Important Files Changed

Filename	Overview
tests/llm_translation/test_bedrock_gpt_oss.py	Stubs the flaky live streaming test and adds a mock request-body transformation test; the new test has an implicit AWS credential dependency that can cause a confusing AssertionError in environments without credentials.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[test_function_calling_request_body_gpt_oss] --> B[litellm.completion called]
    B --> C[converse_handler.completion]
    C --> D[get_credentials - boto3.Session]
    D -->|No credentials in env| E[SigV4Auth.add_auth raises AttributeError]
    D -->|Credentials available| F[get_request_headers - SigV4 sign]
    E --> G[except Exception: pass]
    G --> H[mock_post.assert_called_once FAILS: called 0 times]
    F --> I[client.post called - MOCKED]
    I --> J[mock_post.assert_called_once passes]
    J --> K[Assert URL, request body, tool schema stripping]

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_{Reviews (2): Last reviewed commit: "[Test] add request-body mock test for be..." | Re-trigger Greptile}

[greptile-apps]

Implementation diverges from PR description

The PR description says the fix is @pytest.mark.flaky(retries=6, delay=5) delegating to super(), but the actual implementation is a bare pass that permanently skips the test — the same pattern used for features Bedrock GPT-OSS simply doesn't support (prompt caching, zero-cost tokens). Those are permanent capability gaps; a flaky model endpoint is not. The pass approach removes all streaming tool-call coverage for this provider rather than retrying through transient failures.

If the intent is to tolerate intermittent failures, the body should delegate to the parent and rely on the flaky decorator:

import pytest_retry  # or: from pytest_retry import flaky
# ensure `pytest-retry` is in test deps

@pytest.mark.flaky(retries=6, delay=5)
def test_function_calling_with_tool_response(self):
    """Bedrock GPT-OSS intermittently emits truncated toolUse.input deltas."""
    super().test_function_calling_with_tool_response()

If permanently skipping is the intent, the docstring and PR description should be updated to say so explicitly.

Rule Used: What: Flag any modifications to existing tests and... (source)