[CI/Build] Fixed a test for invalid CLI argument validation in test_cli_args.py

https://github.com/vllm-project/vllm/pull/46779

Purpose

In two tests, tests/entrypoints/openai/test_cli_args.py presented incorrect contract information, leading to a false sense of certainty.

It claimed that when combined1 with test_enable_auto_choice_fails_with_enable_reasoning-enable-auto-tool-choice, -reasoning-parser should fail. However, this combination is documented as supported (e.g., ) and does not fail correctly. The test passed because was omitted, which triggered the irrelevant check “Automatic tool selection requires a tool-call parser,” obscuring the fact that an inference conflict validation does not exist (and should not exist). I rewrote the code to ensure that documented combinations pass when the tool call parser is enabled.docs/features/tool_calling.md-tool-call-parser hunyuan_a13b --reasoning-parser hunyuan_a13bvalidate_parsed_serve_args-tool-call-parser 2. test_enable_auto_choice_passes_without_tool_call_parser was misnamed. The function’s docstring and body explicitly state that the validation fails. test_enable_auto_choice_fails_without_tool_call_parser I renamed it to match the actual behavior.

This is a test-only change; runtime behavior remains unchanged.

This is not a duplicate. I searched for public PRs regarding test_cli_args, validate_parsed_serve_args, and test_enable_auto_choice, but none of them touched this test.

Test Plan

python -m pytest tests/entrypoints/openai/test_cli_args.py -v
# lint
ruff check tests/entrypoints/openai/test_cli_args.py
ruff format --check tests/entrypoints/openai/test_cli_args.py

Test Results

28 passed in 5.48s
ruff: All checks passed! / 1 file already formatted