[omartelo]

lich publishes every hook contract as bytes now — docs/hooks/fixtures/*.jsonl, one case per line, each naming a payload and whether lich accepts (204) or refuses (400) it — and asserts its own endpoints against them in internal/terminal/fixtures_test.go. This is the other half: the scripts in this repository build those payloads, so until now a renamed field went red only on lich's side.

node --test tests/*.test.mjs drives every hook script as a real subprocess, using the command line taken from the registration each harness actually reads (hooks/hooks.json, hooks/codex-hooks.json — quoting included), pointed at a stub HTTP server, and asserts the body it POSTs.

What is asserted

Assertion	Covers
Registration sweep (18 cases)	every script × both harnesses: exactly one request, POST, application/json, key set and value classes match some accept case's body, violates no reject case, no claude_session_id
Endpoint + token	/hook, /session-start, /session-title, /session-touched, each with ?token=$LICH_TOKEN
Reject rules	one predicate per rejected case; a rejected case with no rule fails its own test, so a contract that grows a refusal cannot slip through unmodelled
Enum pinning	accepted states and providers are derived from the fixtures, not copied beside them; registration arguments are checked against them (all four states registered by both harnesses, claude/codex only)
Provider	the Codex registration sends "provider":"codex", Claude's sends "claude", a bare invocation defaults to claude
Title extraction	Claude's ai-title line, Codex's first user_message, trimmed, JSON-escaped (quotes, backslash, tab), plus six cases that must stay silent
sed fallback	session-start still parses the payload with jq removed from PATH (Windows)
Client rules (24 cases)	five partial-environment shapes report nothing and exit 0; a 500 and a refused connection both exit 0 with an empty stdout — per script

Stdout is asserted empty everywhere. That is load-bearing on Codex, where a hook's own exit code answers a PermissionRequest.

One payload disagreed with the contract

report-title.sh checked that it had extracted something before posting:

POST /session-title  {"session_id":"…","title":"   "}

which violates the blank title case in session-title.jsonl — lich answers 400. Codex made it reachable: it names a thread after its first user message, so a prompt whose first line is indentation produced exactly that payload. Fixed in the script by trimming before the check, which also matches what lich stores. The fixture was not touched.

Nothing else disagreed.

Vendored, not fetched

The fixtures live in tests/fixtures/ as byte-identical copies, so no test reaches the network — network in a test is flake, drift is not. tests/refresh-fixtures.sh re-pulls them, and the new fixtures-drift CI job re-pulls and git diff --exit-codes the copies against omartelo/lich@main, so a contract that moves upstream goes red here on the next run.

Test plan

• node --test tests/*.test.mjs — 61 pass, 0 fail
• Mutation-checked that the assertions bite: state:"Busy" → 10 fail, claude_session_id re-added → 4 fail, path /session-touch → 2 fail, session_id dropped from the title body → 4 fail
• tests/refresh-fixtures.sh followed by git diff --exit-code -- tests/fixtures is clean