writeonce/docs/stories/language-runtime-database/07-logwatcher-proof.md

Iteration 7 — log-watcher proof workload

Format: product/story-iteration-template. Part of Story — one language, one runtime, one database, one binary.

Goals

• The language's driving workload runs for real: the Haxe log-watcher daemon (~1,200 lines) re-expressed file-for-file in .wo at docs/examples/log-watcher/, compiled by woc, detecting a silent death on a live file.
• The README mapping table's "could not express" column is empty — the systems track's acceptance bar: nothing in a real daemon exceeded the language.

Status: ✅ landed 2026-08-15. Compile-and-run met 2026-08-14 (zero diagnostics, 106 KB standalone binary, all three modes work); the executable half landed 2026-08-15 — zero ASan leaks in all three modes, SIGTERM ends parked syscalls, fds flat across 200 requests, and the LW_SOAK gate holds RSS/descriptors flat under sustained load. just log-watcher: 7 checks, 0 failures. The work is recorded in plan/compiler/2026-08-14-logwatcher-executable.md and nothing else blocks this iteration.

Acceptance Criteria

• What to achieve?
  • Given the eight-file .wo port (logtail, watcher, cron, probes, supervisor, mcp, tools, main),
  • when woc compiles the sample and the ported fixture groups run,
  • then compilation is clean and every fixture mirrors its named Haxe test case with matching behavior.
• What to achieve?
  • Given the built sample running watch against a growing tempfile,
  • when the feed ends with an error line and the quiet period elapses,
  • then exactly one detection line appends to the JSONL sink — the original's measured behavior, reproduced.
• What to achieve?
  • Given the README mapping table,
  • when the iteration closes,
  • then every row names its .hx sibling and deliberate divergences, and the could-not-express column is empty.
• What to achieve? (added 2026-08-14 — compiling is not running)
  • Given any of the three modes started under a sanitizer build,
  • when it is signalled to stop after a soak,
  • then it exits cleanly on SIGTERM alone, reports zero leaks, and its resident size and descriptor count are flat across the soak.

Out Of Scope

• The sqlite-backed minilog tools — expressible when iteration 9's SQL lands; recorded as scoped-out, not inexpressible.
• New language or stdlib features: a gap found here is a defect report against iterations 5/6, and this iteration stops until it's resolved.

Info

• The .wo files may be authored docs-first ahead of this iteration (spec 2026-08-07-logwatcher-sample-and-principles-design.md); this iteration is where they must actually compile and run.
• The pure-core discipline (tail state machine, cron math, MCP handle socket-free and clock-injected) is preserved — the original's best design decision.

Proposed Solution

• The authoring plan (docs/superpowers/plans/2026-08-01-log-watcher-sample.md) is spent: the .wo files exist and compile.
• What remains is plan/compiler/2026-08-14-logwatcher-executable.md — six tasks, every one traced to a measurement on this sample: the ownership pass learning stdlib return types, dropping a projected temporary, the runtime's own argv container, honouring the stop signal in blocking calls, closing accepted connections, and a soak that would have caught all of it.
• just log-watcher (scripts/log-watcher-accept.sh) is this iteration's gate: compile, watch alert, cron schedule, and three MCP checks today; the soak joins it in the last task.