Imported from Capsem triage report tooling-06-missing-tests-mock-http-routing-shapes.md.
- Severity:
medium
- Category:
missing-test
- Area:
capsem-mock-server
- Location:
crates/capsem-mock-server/src/main.rs:306-602 (route), MCP/model builders 745-1317; tests in mod tests at 1631-1677
- Confidence:
verified
Summary
The mock exists to stand in for real upstreams so proxy/model/MCP tests can assert against a known shape. Yet only three things are tested: deterministic_bytes caching, the DNS fixture answer, and the WebSocket accept hash. The entire HTTP route table — the tool-call branching in openai_chat_response, the streaming-vs-nonstreaming branch selection, mcp_response, responses_response, the Anthropic/Gemini shapes, and the log_request record schema — has no coverage. A drift between the mock's emitted shape and the contract the proxy tests rely on would not be caught here.
Evidence
Test module (lines 1631-1677) contains exactly: deterministic_bytes_are_cached_and_correct (1636), dns_fixture_answers_known_names_and_rejects_unknown (1645), websocket_accept_matches_rfc_fixture (1659). No test constructs a request and calls route(), nor asserts on any model/MCP builder output.
High-value untested logic with real branching:
openai_chat_response (745): emits a tool call iff tools present OR is_baked_doctor_openai_smoke matches (793) — a narrow exact-match heuristic (single user message, content == "hello", model == "mock-local") that silently changes the response shape.mcp_response (1256): method dispatch for initialize/tools.list/tools.call/resources.* and the -32601 fallback.mcp_payload_should_delay (1319): the doc://slow / slow_sleep trigger that injects a 2s sleep.find_hex32 (1220) / find_root_txt_path (1228) / write_target (1212): token/path extraction that determines the printf ... > path command every model fixture emits.log_request (1339): the JSON record schema (lowercased headers, /log body omission, response-byte accounting via the LogBody extension).
Impact
The mock's job is contract fidelity. Any of the above can drift (e.g. a builder field rename, a changed dispatch key, a broken token-extraction regex) and every consuming test would keep passing while silently asserting against the wrong upstream shape — exactly the failure mode that makes a mock dangerous.
Suggested fix
Add unit tests that call route() (or the individual builders) with representative request bodies and assert on the parsed JSON shape: tool-call vs no-tool-call selection, MCP dispatch results and the error fallback, write_target extraction over a payload containing a hex32 token and a /root/...txt path, and a log_request round-trip asserting the record fields (especially /log body omission and lowercased header keys).
Triage
Confirmed from the local reviewed report in /Users/elie/git/capsem/tmp/bugs/tooling-06-missing-tests-mock-http-routing-shapes.md. Track implementation in the triage sprint; add regression coverage before fixing.
Imported from Capsem triage report
tooling-06-missing-tests-mock-http-routing-shapes.md.mediummissing-testcapsem-mock-servercrates/capsem-mock-server/src/main.rs:306-602(route), MCP/model builders745-1317; tests inmod testsat1631-1677verifiedSummary
The mock exists to stand in for real upstreams so proxy/model/MCP tests can assert against a known shape. Yet only three things are tested:
deterministic_bytescaching, the DNS fixture answer, and the WebSocket accept hash. The entire HTTProutetable — the tool-call branching inopenai_chat_response, the streaming-vs-nonstreaming branch selection,mcp_response,responses_response, the Anthropic/Gemini shapes, and thelog_requestrecord schema — has no coverage. A drift between the mock's emitted shape and the contract the proxy tests rely on would not be caught here.Evidence
Test module (lines 1631-1677) contains exactly:
deterministic_bytes_are_cached_and_correct(1636),dns_fixture_answers_known_names_and_rejects_unknown(1645),websocket_accept_matches_rfc_fixture(1659). No test constructs a request and callsroute(), nor asserts on any model/MCP builder output.High-value untested logic with real branching:
openai_chat_response(745): emits a tool call ifftoolspresent ORis_baked_doctor_openai_smokematches (793) — a narrow exact-match heuristic (single user message, content == "hello", model == "mock-local") that silently changes the response shape.mcp_response(1256): method dispatch for initialize/tools.list/tools.call/resources.* and the-32601fallback.mcp_payload_should_delay(1319): thedoc://slow/slow_sleeptrigger that injects a 2s sleep.find_hex32(1220) /find_root_txt_path(1228) /write_target(1212): token/path extraction that determines theprintf ... > pathcommand every model fixture emits.log_request(1339): the JSON record schema (lowercased headers,/logbody omission, response-byte accounting via theLogBodyextension).Impact
The mock's job is contract fidelity. Any of the above can drift (e.g. a builder field rename, a changed dispatch key, a broken token-extraction regex) and every consuming test would keep passing while silently asserting against the wrong upstream shape — exactly the failure mode that makes a mock dangerous.
Suggested fix
Add unit tests that call
route()(or the individual builders) with representative request bodies and assert on the parsed JSON shape: tool-call vs no-tool-call selection, MCP dispatch results and the error fallback,write_targetextraction over a payload containing a hex32 token and a/root/...txtpath, and alog_requestround-trip asserting the record fields (especially/logbody omission and lowercased header keys).Triage
Confirmed from the local reviewed report in
/Users/elie/git/capsem/tmp/bugs/tooling-06-missing-tests-mock-http-routing-shapes.md. Track implementation in the triage sprint; add regression coverage before fixing.