The previous check proved _load_endpoints_config returns a fresh object by
clearing the first result and reloading. That mutates shared state and only
works while the loader happens not to cache, so a future cache would corrupt
every later test rather than fail this one.
Compare the two loads by identity and equality instead. Verified red-before-green:
adding a module-level cache to the loader fails this test, removing it passes.
Mutation testing surfaced three factory functions whose tests ran against them
but asserted nothing that a mutation could break, so every planted bug survived.
- litellm/llms/litellm_proxy/skills/code_execution.py: the OpenAI and Anthropic
tool schemas were unpinned (the Anthropic one was not reached by any test at
all) and the handler's default fallbacks were unchecked
- litellm/containers/endpoint_factory.py: the endpoints.json contract, the
generated sync/async function set and the response-type mapping were unpinned
- litellm/llms/openai_like/dynamic_config.py: the generated Responses API config
class had no coverage of auth header, URL resolution or the store override
The openai_like tests clear _responses_config_cache around each test. Without
that, the module-level cache hands back a class built before the mutation and
the tests pass against mutated code.
Verified by re-running mutmut per scope:
llms/litellm_proxy 45.2% -> 62.8% (70 mutants newly killed)
containers 36.8% -> 84.3% (45 mutants newly killed)
llms/openai_like 55.7% -> 66.9% (34 mutants newly killed)
