rose-ash/plans/agent-briefings/sx-gate-loop.md

W14 — Test gate & conformance infrastructure loop

Forge agent ws-W14. Role: build out W14 from the SX review remediation plan (plans/sx-review/PLAN.md, §"W14. Test gate & conformance infrastructure") — the enabler that makes every other fix verifiable. One checklist item per fire.

You are on branch loops/sx-ws-w14, worktree /root/rose-ash-loops/sx-ws-w14.

Hard guardrails (read every fire)

• TEST-ONLY. No semantics edits. Do NOT touch spec/evaluator.sx, spec/primitives.sx, spec/parser.sx, spec/render.sx, the OCaml kernel, or any host runtime. W14 pins behavior with tests and productionizes the test/runner surface; the actual fixes are other workstreams (W1–W12). A pin that fails means the finding regressed — do NOT relax the assertion, record it as a blocker.
• NO PUSH. Commit locally on loops/sx-ws-w14 only. Never push; never touch main or architecture.
• .sx files: use sx-tree MCP tools only (a hook blocks Read/Write/Edit on .sx). sx_write_file takes params file and source (NOT content — a wrong key yields a yojson … got null error and no write). .md/.sh/.ml files: normal tools are fine.
• Never pkill/kill sx_server — sibling loops share the binary. Bound every run with timeout (e.g. timeout 300 …); if it hangs, let the timeout end it.
• One item per fire, then stop. No batching.

Per-iteration procedure

1. Pick the first unchecked [ ] in the checklist.
2. Implement (test file or runner/harness change), lifting minimal repros from the review lane files (plans/sx-review/{core,hosts,conformance}.md) — they are a ready-made corpus of confirmed reprs.
3. Build + run the affected tests: sx_build (target ocaml) then timeout 300 ./hosts/ocaml/_build/default/bin/run_tests.exe <test-name> to run a single file. New spec/tests/test-*.sx files are auto-discovered.
4. Confirm green (a pin must PASS on current HEAD — the fix already landed).
5. Commit locally: git add -A && git commit with a W14: prefix.
6. Tick the box, prepend one dated line to the Progress log, stop.

Checklist

A. Test-debt pins — dc7aa709's landed fixes shipped without regression tests

Pin each confirmed-and-fixed finding with a minimal repro. Add suites to spec/tests/test-gate-pins.sx (one defsuite per finding).

• K18 [W7] — expt overflow now float-promotes (no 63-bit wrap)
• K20 [W7] — contains? now supports dict key membership
• K09/K11/K39 [W5] — longhand unquote-splicing, guard sentinel gensym, do IIFE-head
• K49 [W8] — five void elements (area/base/embed/param/track) renderable (spec side; native regen drift → see Blocked). NB: the depth/cycle guard is K16 [W8], still OPEN — not a W14 pin target until its fix lands
• crit-2 [W1] — signal-return kont pinned NON-VACUOUSLY (side-effect sentinel across two tests; a plain assert would inherit the vacuity)
• C1/C1b [W3] — command-channel crash guards pinned (scripts/test-protocol-gate.sh, seed for section E's fuzz suite)
• S4 [hosts] — soft error pages not cached (HTTP-mode pin in scripts/test-protocol-gate.sh; NB S4 lives in hosts.md, not conformance — "housekeeping" was a mislabel from F-15's tag)

B. Runner/production env unification

• Audit runner-only bindings — inventory + bidirectional ledger in scripts/test-env-parity.sh (KNOWN_DRIFT: values, call-with-values, contains-char?, trim-right, sha3-256; consequence pin: canonical-serialize broken on server; BOTH runners' sha3-256 are FAKE stubs → test CIDs ≠ production CIDs)

C. Harness honesty

• K19 — harness/runtime parity pinned (scripts/test-harness-parity.sh: drives mcp_tree sx_eval over JSON-RPC vs fresh sx_server over epoch, 12-probe battery from the finding, errors compared by message)
• C22/K104 — harness logs IO before invoking the mock (throwing-mock pin)
• C21 — real perform/suspend mode in harness
• C23 — adapter-dom render-output tests

D. WASM corpus runner

• F2 — promote conformance's run_wasm.js prototype into CI

E. Epoch-loop protocol fuzz + skip-list

• C3/C4/C5/C6/C7 — epoch protocol fuzz suite
• F10 — hs-upstream skip-list so browser-only FAILs mean something
• C9 — empty suite label

F. Differential battery

• F8 — cross-host differential battery (same source, all hosts agree)

Progress log (newest first)

• 2026-07-04 — K19 harness-parity pin (item C.1). Authored scripts/test-harness-parity.sh: drives mcp_tree.exe sx_eval with raw JSON-RPC over stdio and a fresh sx_server.exe over the epoch protocol, running the finding's exact 12-probe battery (empty?/get/ split/equal?/contains?/keyword-name/char-code/parse-number) through both and failing on ANY divergence. Errors normalized to their inner message so identical failures compare equal (keyword-name :kw errors the same way on both — keywords evaluate to strings before the call). Result: 12/12 parity — dc7aa709's 8-entry stopgap alignment holds; this pin keeps it honest until the real fix (mcp_tree links sx_primitives) lands in the hosts lane. Test-only.
• 2026-07-04 — Section B: env-parity audit + ledger. Probed a fresh sx_server over the epoch protocol (deps-check + live eval). Confirmed runner-only drift: values/call-with-values (run_tests.ml:1131/1140), contains-char? (rt.ml:728 + rt.js:85), trim-right (JS runner only — absent even from the OCaml runner), sha3-256 (rt.ml:745 + rt.js:88). Consequence verified live: (canonical-serialize 42) on the server → Undefined symbol: contains-char? (content addressing broken for ANY number outside the runners). Worse than the finding: BOTH runners' sha3-256 are FAKE stubs (OCaml uses Hashtbl.hash!) while production has real crypto-sha3-256 — every CID computed in tests differs from production CIDs. Authored scripts/test-env-parity.sh as a bidirectional ledger: MUST_HAVE regressions fail; a KNOWN_DRIFT binding appearing also fails (forces ledger + consequence-pin update when W5/W7/W12 land fixes). 7/7 green. Test-only.
• 2026-07-04 — S4 error-page-cache pin (item A.7) — section A COMPLETE. Extended scripts/test-protocol-gate.sh with an HTTP-mode case: fresh sx_server.exe --http <random-port> (timeout-bounded, own PID killed at end), GET the same nonexistent path twice, assert BOTH requests re-render (2 [sx-http] lines — pre-fix the 2nd was cache-served at 0.0005s) and the [cache] … error page, not cached is_err gate line appears. Findings from prototyping: standalone worktree renders ALL docs pages as soft error pages (no content), so a positive "real page IS cached" control is not assertable here — documented in the script; startup takes ~12-15s (poll loop, 40s budget). 5/5 protocol-gate green + 267/0 sx pins. Test-only.
• 2026-07-04 — C1/C1b command-channel pins (item A.6). These are protocol-level, not .sx-suite pins: authored scripts/test-protocol-gate.sh — each case spawns its OWN timeout-bounded sx_server.exe (no shared process touched) and asserts three things: an (error N "Malformed command line: ...") response is emitted, the follow-up epoch still evaluates (process survived), and no Fatal error escapes / exit is clean. Cases: C1 unterminated list (exact review repro), C1 plain-garbage line, C1b non-ASCII byte (café), plus a well-formed control session. 4/4 green. The script is deliberately structured to grow into section E's fuzz suite (C3–C7). Test-only.
• 2026-07-04 — crit-2 non-vacuous pin (item A.5). The original bug's signature — handler value becomes the WHOLE program result, discarding every outer frame including the covering test's own assert — means a plain (assert= repro expected) pin would pass vacuously on regression. Added suite gate-crit2-signal-return-kont with a side-effect sentinel: test 1 runs both repros (("outer" 43 "end") list shape + raise-continuable → 143) then set!s a top-level flag; test 2 independently asserts the flag — if the continuation is ever dropped again, test 1 "passes" but test 2 fails loudly. Third test pins the exact shipped-test expr (51). Verified both repro shapes live via sx_eval first. 267 passed / 0 failed. Test-only.
• 2026-07-03 — K49 void-elements pin (item A.4) + regen-drift DISCOVERY. Corrected the checklist label first: K49 is "five void elements unrenderable" (core.md:335), not the depth guard (that's K16, OPEN). Added suite gate-K49-void-elements-renderable (3 tests): spec HTML_TAGS contains all five; (render-to-html '(base :href "x") (make-env)) → <base href="x" />; all five render self-closing. Runner-env gotchas: current-env/symbol are not bound in run_tests — use (make-env) and literal quoted forms. Discovery: the first draft pinned via the runner's native render-html and FAILED — hosts/ocaml/lib/sx_render.ml (generated) was never regenerated after dc7aa709's spec fix, so the native render path still errors on the five tags. Recorded under Blocked; live evidence for F13 (regen-diff gate). 264 passed / 0 failed. Test-only.
• 2026-07-03 — K09/K11/K39 W5 special-form pins (item A.3). Three suites added to spec/tests/test-gate-pins.sx: gate-K09-longhand-unquote-splicing (R7RS longhand (unquote-splicing X) now splices, incl. empty-list case; shorthand still works), gate-K11-guard-reraise-forgeable (a body/clause value shaped like (list '__guard-reraise__ X) is returned as data, not misread as a re-raise — sentinel is now gensym'd), gate-K39-do-iife-head ((do ((fn (x) x) 5) 99) → 99, not a misparsed do-loop — exact core.md repro). Gotchas hit and fixed: quasiquoted bare idents are symbols not strings, and assert= compares with = (not equal?, which returns false on these spliced lists). 261 passed / 0 failed under OCaml run_tests. Test-only.
• 2026-07-03 — K20 contains?-dict pin (item A.2). Mapped K-codes by core.md severity order (K17 append!, K18 expt, K19 harness-drift, K20 contains?-dict). Added suite gate-K20-contains-dict to spec/tests/test-gate-pins.sx (4 tests): present dict key → true, missing key → false, list membership unchanged, string substring unchanged. Repro from core.md ("(contains? {:a 1} :a) threw contains?: 2 args"). 8/8 green across both suites under OCaml run_tests. Test-only.
• 2026-07-03 — K18 expt-overflow pin (item A.1). Bootstrapped this briefing from PLAN.md §W14 (the referenced file did not exist yet). Added spec/tests/test-gate-pins.sx with suite gate-K18-expt-overflow (4 tests): small exponents stay exact (2^0=1, 2^10=1024), 2^62 > 0 (no negative 63-bit wrap), 2^100 > 0 (no wrap-to-zero), 2^100 is a number (float promotion). Verified 4/4 green under the OCaml run_tests kernel. Test-only.

Blocked

• K49 native path — sx_render.ml regen drift (found 2026-07-03 while pinning A.4): dc7aa709 fixed HTML_TAGS in spec/render.sx but never re-ran hosts/ocaml/bootstrap_render.py, so the generated hosts/ocaml/lib/sx_render.ml still carries a stale html_tags_list without area/base/embed/param/track. The runner's native render-html convenience (and any native fast-path render) therefore STILL throws Undefined symbol: base — dc7aa709's "verified on the native binary" claim did not cover this path. Fix = regen (hosts lane, semantics-adjacent — out of scope for this test-only loop). This is a live instance of F13 (regen-diff CI gate, section-B/D territory): a regen-diff check would have caught it at commit time. The K49 pin covers the spec side only; when the regen lands, extend the suite with render-html-path assertions.