litellm/tests/unit/router_utils
tin-berri 8e2e99670d
fix(router): continue Responses mid-stream fallbacks on models without assistant prefill (#47672)
* fix(router): avoid assistant prefill in Responses fallbacks

* fix(router): keep prefill for Claude fallbacks that take it and skip constrained continuations

A Responses fallback to a Claude model that takes assistant prefill now gets
the partial response as prefill again, so it continues mid-word without the
prompt-shape drift. Every other fallback keeps the request to continue.

A stream cut after text no longer continues when the request constrains its
output (a json_schema or json_object text format, or a forced tool_choice),
since a continued JSON document or tool call would not parse. The client gets
the primary's error, as on the chat path.

The fallback's re-sent leading space at the seam is dropped, and the prefill
shaping runs per deployment after the encrypted reasoning strip, so stripped
reasoning is never replayed.

* fix(router): guard SDK text_format, narrow forced tool_choice, read Claude base_model, and cap Responses continuation output

Cut Responses streams that asked for structured output through the SDK's text_format now surface the primary's
error instead of stitching two models' JSON. Only a required or named tool_choice counts as forced, so allowed_tools
in auto mode and hosted tool choices still continue. A Claude deployment named only through base_model keeps its
prefill continuation, and the continuation's max_output_tokens is lowered by what the cut stream already emitted.

* fix(router): quote the partial's ending in the continue request and surface the primary's error after a cut tool call

* fix(router): stop Responses fallbacks from continuing content-filter cuts and client-run tool calls

A content filter that cuts a /v1/responses stream mid-answer now returns its error, as on chat, instead of letting a content_policy_fallbacks backup finish the filtered text. Shell, apply_patch, computer, local_shell, and MCP approval items count as a started tool call. Chat continuation goes back to treating any tool_choice object as constraining, as on main

* fix(responses): count a stream of tool arguments as a started tool call

* fix(router): let Responses fallbacks continue under allowed_tools auto and after server-run tool calls

A Responses tool_choice of allowed_tools in auto mode no longer blocks the continuation, since the model may still answer in text. Hosted MCP calls and the bridge's server-run tool search no longer count as a started client tool call.

---------

Co-authored-by: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
2026-10-28 04:34:40 -07:00
..
pre_call_checks fix(router): continue Responses mid-stream fallbacks on models without assistant prefill (#47672) 2026-10-28 04:34:40 -07:00
__init__.py test: add __init__.py to intermediate tests/unit packages 2026-09-20 12:55:27 +00:00
test_access_windows.py test: move tests/test_litellm core utils, routing, responses, caching and rust_bridge into tests/unit (#43199) 2026-09-25 17:10:13 -07:00
test_add_retry_fallback_headers.py refactor: expose public hidden_params accessors (#44668) 2026-10-07 00:01:33 -07:00
test_auto_router_model_naming.py feat(ui): streamline auto-router setup with deployed decision models (#45913) 2026-10-10 20:49:59 -07:00
test_auto_router_tuning_baseline.py fix(auto-router): separate tuning and select chained heuristic (#44928) 2026-10-06 13:43:53 -07:00
test_baseline_request.py fix(router): preserve native baseline identity and accounting (#44960) 2026-10-07 11:00:31 -07:00
test_batch_utils.py fix(batches): retry confirmed pre-accounting failures (#47625) 2026-10-20 14:12:26 -07:00
test_client_initalization_utils.py test: move tests/test_litellm core utils, routing, responses, caching and rust_bridge into tests/unit (#43199) 2026-09-25 17:10:13 -07:00
test_cooldown_cache.py refactor: expose core private helpers under public names (#44871) 2026-10-07 00:05:27 +00:00
test_cooldown_handlers.py fix(router)!: count an explicit allowed_fails of 3 and keep fallback deployments out of cooldown (#46183) 2026-10-28 03:19:26 -07:00
test_deployment_pricing.py fix(router): price cost-based routing through model_info.base_model (#47617) 2026-10-20 22:20:16 +00:00
test_embedding_batch_size_check.py feat(embeddings): enforce per-request input batch limit (#44574) 2026-10-20 11:35:18 +00:00
test_fallback_event_handlers.py fix(router): keep a lone deployment warm under router allowed_fails unless the policy names the exception (#48644) 2026-10-27 15:12:53 -07:00
test_get_retry_from_policy.py fix(exceptions): map upstream 402 to PaymentRequiredError and cool down 402 deployments (#44879) 2026-10-06 20:35:13 -07:00
test_handle_error.py test: move whole-unit legacy test files into tests/unit and delete dead skips (#44807) 2026-10-07 05:02:28 +00:00
test_health_check_allowed_fails_integration.py refactor: expose core private helpers under public names (#44871) 2026-10-07 00:05:27 +00:00
test_health_state_cache.py test: move tests/test_litellm core utils, routing, responses, caching and rust_bridge into tests/unit (#43199) 2026-09-25 17:10:13 -07:00
test_kubernetes_pod_discovery.py feat(ui): show kubernetes pods on the model page (#44666) 2026-10-19 09:58:20 -07:00
test_pattern_match_deployments.py fix(proxy): match partial wildcards against prefix-stripped model ids (#46390) 2026-10-20 02:49:42 +00:00
test_prompt_caching_cache.py fix(router): skip non-dict tool entries in the prompt caching affinity key instead of raising (#47565) 2026-10-20 08:03:31 -07:00
test_ptu_shares.py feat(proxy): split Azure PTU deployments across teams with per-team PTU ceilings and PTU-hour reporting (#43043) 2026-10-15 18:44:30 +00:00
test_reasoning_effort_capability.py refactor(llms): rename model-version transformation files to family names (#48509) 2026-10-26 18:53:16 -07:00
test_request_priority.py fix(router)!: schedule default_priority requests once and reject a malformed priority (#47498) 2026-10-20 08:00:57 +00:00
test_router_health_check_routing.py test: move tests/test_litellm core utils, routing, responses, caching and rust_bridge into tests/unit (#43199) 2026-09-25 17:10:13 -07:00
test_router_interactions_endpoints.py test: move tests/test_litellm core utils, routing, responses, caching and rust_bridge into tests/unit (#43199) 2026-09-25 17:10:13 -07:00
test_router_utils_common_utils.py fix(proxy)!: answer 400 for malformed tools on count_tokens instead of crashing (#46583) 2026-10-16 14:57:53 -07:00
test_routing_read_batch.py refactor: expose core private helpers under public names (#44871) 2026-10-07 00:05:27 +00:00