Closes#2074
Adds FauxStep::Factory(Box<dyn Fn(&MessageRequest) -> CannedTurn + Send + Sync>)
to MockLlmClient. When a Factory step is dequeued, its closure runs
against the real outgoing MessageRequest before the response stream is
built, so any assert! panic surfaces directly from the client call
instead of later in stream polling.
Internal storage moves from VecDeque<CannedTurn> to VecDeque<FauxStep>,
but every existing public method keeps working:
- MockLlmClient::new(Vec<CannedTurn>) wraps each turn in FauxStep::Canned.
- push_turn(CannedTurn) appends as FauxStep::Canned.
Adds push_factory(closure) for tests that want the Factory branch.
Doc comment on the Factory variant captures the DeepSeek V4
thinking-mode tool-call invariant (the v0.4.9-v0.5.1 reasoning_content
drop that produced HTTP 400 on follow-up turns).
Adds:
- crates/tui/tests/reasoning_content_replayed_after_tool_call.rs — a
regression test whose factory asserts the assistant tool-call turn
carries a Thinking content block after a thinking + tool-call round.
- An additional unit test in mock.rs covering create_message_synthesizes_from_factory_turn.
All 20 tests in the new file pass, and the existing
integration_mock_llm suite (27 tests) is unchanged.
Matt Van Horn
de3a1f7773