[Upd4ting]

Why

A module created from this template should spend as little time as possible on install, build, test, start and reload (ANT-1957, the second wave of the org-wide perf pass). typecheck (tsc --noEmit) and the compiles of pnpm build and pnpm test (tsc --skipLibCheck) shared one incremental state file, dist/.tsbuildinfo. Each run overwrote it with different options. A typecheck that ran after a test or a build found the --skipLibCheck state, so it checked every declaration file again. That happens on every pnpm run checks after the first and on every pre-push hook after a test.

Summary

typecheck now keeps its own state file with --tsBuildInfoFile node_modules/.cache/typecheck/.tsbuildinfo, next to the tsconfig.config.json cache already in node_modules/.cache. It checks the same program with the same options, so the diagnostics stay the same. A cached error still fails the next run. tsc itself invalidates the file from file hashes and options. pnpm build and pnpm test keep dist/.tsbuildinfo. antelopejs-sync --check accepts the script.

Readability cost: one flag on the typecheck script.

Workload and numbers

The numbers come from a module created with ajs module init --template "Module Typescript" --pm pnpm through antelopejs-verify, then pnpm install --frozen-lockfile, from current main. Node 24.22.2, pnpm 10.6.5, on a shared 16-core server.

Command	Before	After	Runs per side
pnpm run checks, repeated, before and after alternating	median 3246 ms (3146 to 4016)	median 2528 ms (2286 to 3339)	8
pnpm typecheck right after pnpm test	mean 1486 ms (1413 to 1571)	mean 592 ms (571 to 636)	8

A second interleaved run of checks on a module that already had the npx fix (#38) gave the same picture: median 3032 ms (2912 to 3480) before, 2209 ms (2143 to 2486) after. The first typecheck on a fresh clone still pays the full check, about 1.46 s, as before.

Evidence level: confirmed through end-to-end benchmarks. Impact: Medium. It saves about 0.7 to 0.9 s on each pnpm run checks after the first, a 22 to 27% cut, and about 0.9 s on each pre-push hook that follows a test or a build.

Correctness check: with export const bad: number = "x"; appended to src/index.ts, two pnpm typecheck runs in a row both fail with TS2322, and the run after the fix passes.

Related issue

ANT-1957. @antelopejs/tooling-configs writes typecheck: "tsc --noEmit" as its default script, so other templates that also build with --skipLibCheck likely pay the same cost. That belongs in tooling-configs, not here.

Verification

• pnpm run checks: Checks: 12 passed, 0 failed.
• antelopejs-verify journey <run> --plan: every journey passes, tooling/scaffold-lint-rejects (an unused local still fails typecheck) and tooling/scaffold-checks included.

Checklist

• The pull request title follows Conventional Commits.
• I added or updated tests when behavior changed. Behavior does not change. scaffold-lint-rejects and scaffold-checks cover it.
• I updated documentation when users or contributors are affected. No document names the typecheck command line.
• I documented breaking changes and migration steps. There are none.
• I did not include credentials or unrelated changes.