Repository navigation
In-browser runner via jco #5
Description
Run a suite in a real browser: transpile suite + host shims with jco (JSPI), drive from Node via a page driver. Lessons from webcrypto's conformance/adapters/jco/ that should be designed in from the start:
- The gating CI adapter and any interactive viewer page must share one harness module, or they drift.
- Worker-pool striping (case
index % workers), not contiguous chunks — expensive cases cluster by group. - Each worker imports its own suite + shim instances and runs its stripe strictly sequentially: no host instance sees two in-flight operations.
- A JS throw from
runmeans the guest was aborted (an unliftable error): record it as that case's failure, treat the instance as poisoned, keep the run alive. - Heartbeats + a stall watchdog; browser located via env var → system names → Playwright cache.
- Same canonical results JSON out.
Activity
lann commentedon Aug 4, 2026
The viewer-page half of this is now tracked separately as #46 (results viewer over the canonical format, useful standalone). The shared-harness constraint recorded here applies whenever #46's page grows a live-run mode.
Results viewer + live browser harness (#46, the page half of #5)
lann commentedon Aug 5, 2026
The viewer half landed (d85d396, see #46): js/viewer's Live pane runs any jco-transpiled suite in a Web Worker pool with the striping/instance-isolation rules this issue records, over a shared browser-safe
harness.mjs(inventory parsing, mark scheduling, the case loop — selftest-gated including striping partition equality). What remains for this issue is the gating browser adapter: a Node page-driver that runs a suite in headless Chromium in CI and emits results-JSONL. Per the one-harness rule, it must consumejs/viewer/harness.mjs+worker.mjsrather than carry its own loop; the heartbeat/stall-watchdog and browser-discovery pieces can port from component-webcrypto'sscripts/browser-page-driver.mjs.Root npm facade: the JS runner core as a rev-pinned git dependency
lann commentedon Aug 11, 2026
Closing: the in-browser runner exists and is consumed, just not via jco. The stack is the exported page-driver plus runtime-linked workers —
js/browser-driver.mjs(Chromium discovery via CHROME_PATH/system/Playwright cache, heartbeat stall watchdog),js/viewer/page-runner.mjs, and the deltic browser worker (#76) — all over the one sharedharness.mjsthis issue demanded, with striping, per-worker instances, trap containment, and canonical results-JSONL, gated by the verify-deltic/verify-viewer selftests and consumed by the webcrypto and websocket browser legs. The jco transpile lane this issue named was deleted in the Phase 4 cutover (#77), which retires the title's mechanism; every recorded lesson is implemented in the replacement.