chore: run jest in two worker processes (closes #426)

The test and test:verbose scripts ran jest with one worker per CPU core,
about 47 processes and 7-8 GiB per run on the shared 48-core build host.
They now pass --maxWorkers=2. One process took the suite past the
30-second cap in script/test, so two it is; the cap is unchanged.
make check, the pre-commit hook and script/cibuild all reach jest
through these scripts. The suite timings quoted in the script/test and
Dockerfile comments are updated to match.

Model: opus-5-5

Dockerfile

@@ -9,9 +9,9 @@ WORKDIR /app
 ENV AUTISTMASK_LINT_NATIVE=1
 
 # script/test's default 30s bound is the host figure, against a suite that
-# takes 23-29s there with three jest workers. In here the same suite starts on
-# a cold jest cache and shares the runner with the rest of the build, so 30s
-# is too tight — it killed a healthy suite at 30.6s on a cold CI cache. 180s
+# runs in about 28s there. In here the same suite starts on a cold jest cache
+# and shares the runner with the rest of the build, so 30s is marginal rather
+# than a bound — it killed a healthy suite at 30.6s on a cold CI cache. 180s
 # still catches a hang in three minutes and cannot be tripped by a suite that
 # is merely running on contended hardware.
 ENV AUTISTMASK_TEST_TIMEOUT=180

TODO.md

@@ -45,16 +45,14 @@ but the review is broader than any of them.
 
 # Completed Steps
 
-- 2026-10-04: `make test` runs jest in three worker processes
+- 2026-10-04: `make test` runs jest in two worker processes
   ([#426](https://git.eeqj.de/sneak/AutistMask/issues/426)). The `test` and
   `test:verbose` scripts in `package.json` ran `jest --forceExit`, which starts
   one worker per CPU core: about 47 processes and 7-8 GiB per run on the shared
-  48-core build host. They now pass `--maxWorkers=3`, and the suite takes 23-29s
-  there: inside the 30-second cap in `script/test`, which is unchanged, but not
-  by much, because `tests/persistedFieldContract.test.js` alone takes most of it
-  ([#428](https://git.eeqj.de/sneak/AutistMask/issues/428)). One or two workers
-  went past the cap. `make check`, the pre-commit hook and `script/cibuild` all
-  run the suite through these scripts.
+  48-core build host. They now pass `--maxWorkers=2`. One process took the suite
+  past the 30-second cap in `script/test`, which is unchanged; two workers stay
+  inside it, though on the busy build host only just. `make check`, the
+  pre-commit hook and `script/cibuild` all run the suite through these scripts.
 
 - 2026-10-04: The error container on each dApp approval screen keeps its height
   when an error appears

package.json

@@ -6,8 +6,8 @@
     "license": "GPL-3.0",
     "private": true,
     "scripts": {
-        "test": "jest --forceExit --maxWorkers=3",
-        "test:verbose": "jest --forceExit --maxWorkers=3 --verbose",
+        "test": "jest --forceExit --maxWorkers=2",
+        "test:verbose": "jest --forceExit --maxWorkers=2 --verbose",
         "build": "node build.js",
         "lint": "eslint . && prettier --check .",
         "fmt": "prettier --write .",

script/test

@@ -1,16 +1,16 @@
 #!/bin/sh
 # script/test: run the test suite.
 #
-# jest runs three worker processes (package.json), not one per CPU core: on a
+# jest runs two worker processes (package.json), not one per CPU core: on a
 # many-core shared host one per core took gigabytes of RAM per run.
 #
 # The timeout bounds a hung suite; it is not a performance budget. On the busy
-# shared build host the suite takes 23-29s with three workers, so
-# REPO_POLICIES' 30s cap is tight there, not comfortable. Inside the image the
-# same suite also pays a cold jest cache and shares the runner with the rest of
-# the build, which is not what that budget describes, so the Dockerfile raises
-# the bound through AUTISTMASK_TEST_TIMEOUT. A cap a healthy suite can trip on a
-# cold cache produces a red that means nothing, and teaches "just run it again".
+# shared build host the suite takes about 28s with two workers and
+# REPO_POLICIES' 30s cap is the bound. Inside the image the same suite also
+# pays a cold jest cache and shares the runner with the rest of the build,
+# which is not what that budget describes, so the Dockerfile raises the bound
+# through AUTISTMASK_TEST_TIMEOUT. A cap a healthy suite can trip on a cold
+# cache produces a red that means nothing, and teaches "just run it again".
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"