# Architect Startup Cheat-Sheet

Fast-start notes for the architect role in this monorepo. Captured from the
`topic-feed` session (2026-08-28) to make the next session's startup faster.

## Tool locations (already installed — do not reinstall or re-verify)
- Language mutation/CRAP/DRY (JavaScript): `psf-memo-client/node_modules/.bin/`
  - `mutate4javascript`, `crap4javascript`, `dry4javascript`
- APS Babashka tools: `tmp/aps/` (single canonical checkout; refresh with
  `swarmforge/scripts/ensure-aps.sh --update`; run via `bb <task>` from that dir)
  - `gherkin-parser`, `gherkin-mutator`, `gherkin-ir-dry-checker`
- Runner adapters (for `gherkin-mutator`):
  - DB: `psf-memo-db/acceptance/lib/runner-worker.js`
  - Client: `psf-memo-client/acceptance/lib/runner-worker.js`

## Language mutation — the `--mutate-all` gotcha (IMPORTANT)
`mutate4javascript` runs in **differential mode** when a manifest is embedded in
the source file: it only re-runs mutations in functions whose hash changed since
the last run. If you add tests to kill survivors but the SOURCE is unchanged, a
plain re-run reports `Killed: 0, Survived: 0, Uncovered: 0` and silently skips
the survivors.

Prefer `swarmforge/scripts/mutate-file.sh`, which detects differential
under-selection automatically (`Selected < Covered`) and reruns once with
`--mutate-all`. Run it from the component directory:
```bash
../swarmforge/scripts/mutate-file.sh src/<file>.js --max-workers 8
```
Manual fallback when you must run the binary directly:
```bash
node ../psf-memo-client/node_modules/mutate4javascript/bin/mutate4javascript.js \
  src/<file>.js --max-workers 8 --mutate-all
```

## Gherkin soft mutation — canonical invocation
Run from `tmp/aps/`. Use `--json` and redirect stderr to `/dev/null` for a
clean parseable report (worker logs go to stderr; the report goes to stdout).
```bash
bb gherkin-mutator \
  --runner-worker "node <component>/acceptance/lib/runner-worker.js" \
  --feature <component>/specs/<feature>.feature \
  --work-dir <component>/tmp/acc-mut-<name> \
  --level soft --workers 8 --status-interval 30s --json \
  2>/dev/null > /tmp/report.json
```
Parse survivors with a small python one-liner over `d['results']` (filter
`Status == 'survived'`).

### Equivalent upper-bound survivors (no project filter hook)
APS `gherkin-mutator` exposes no project-specific mutation-filter hook, so
upper-bound steps such as `the store was read at most <max_entries> entries`
leave survivors when the bound is mutated upward (a larger bound can never
fail). Treat these as intrinsic equivalents, document them in the review
summary, and do not chase them. Prefer exact counts or independently-tied
fixture values when a bound must itself be mutatable.

## Long runs
- Mutation and gherkin-mutator runs take 60-180s each. Use `--max-workers 8` /
  `--workers 8` and `--status-interval` so progress is visible.
- Run verification sequentially (never concurrent with acceptance generation).

## Keep build dirs clean (mutation speed)
`mutate4javascript` copies the whole project (including `tmp/`) into each worker.
Stale `tmp/acceptance` (LevelDB dirs) and `target/mutation-workers` can bloat to
~1.5G and ~14G, making the worker copy alone many GB and mutation runs appear to
hang. `architect-startup.sh` now flags any of these over 100MB as `[FAIL]`.
Clean them before any mutation run:
```bash
swarmforge/scripts/clean-builds.sh
```
This cut a notifications-query mutation run from 20+ minutes to ~2 minutes.

## Refactorer forwards your own review commit back
After you send a `priority: 00` review commit to coder+refactorer, the refactorer
merges and forwards that SAME commit back to you. It is a no-op ("Already up to
date"). Recognize it immediately and just run `done_with_current.sh` — do not
re-process or re-verify.

## Startup smoke test (fast, ~seconds)
```bash
psf-memo-client/node_modules/.bin/mutate4javascript 2>&1 | head -1   # usage
psf-memo-client/node_modules/.bin/dry4javascript --help 2>&1 | head -1  # usage (NOT bare)
cd tmp/aps && bb gherkin-parser --help                              # usage
```

**IMPORTANT — never run bare `dry4javascript` as a smoke check.** With no
arguments it runs the **full test suite** (~1m50s) before reporting, so it is
not a fast readiness probe. Use `dry4javascript --help` (fast, ~0.6s) to
confirm the binary is present and runnable. The same applies to
`architect-startup.sh`, which must check `dry4javascript --help` rather than
bare `dry4javascript`.