The staging directory was dist/.build-XXXXXX. A build that is killed cannot remove it, the next build removed
only its own, and "files": ["dist"] put the leftover into the npm tarball. .gitignore hid it from git status and
the freshness test skipped every name starting with ".build-", so nothing reported it.
The staging directory is now .dist-staging beside the output (.<name>-staging for --out <dir>) and is cleared at
the start of each build. The freshness test no longer skips anything: a stray file under dist/ fails it.
Checked in a scratch copy: a build stopped with SIGKILL after 1.5 s leaves .dist-staging/ and an unchanged dist/;
npm pack lists 36 files, none from the staging directory; the next build removes it. New test for the same on a
temporary package. npm test: 28 pass in 8.2-9.5 s.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
scripts/build.mjs and its commit message state that a failed build does not touch dist/. That held when checked by
hand, and no test covered it, so a later change to the swap could break it unnoticed.
test/build.test.js runs a copy of the script in a temporary package with one source file and the dist/ of an
earlier build, and compares every file and directory of that package before and after. Two cases: a type error
(the first compiler run fails, TS2322) and "export =" (CommonJS compiles, the ES module run fails with TS1203, so
the staging directory already holds cjs/ and types/).
Checked in a scratch copy: with the cleanup of the staging directory removed both tests fail; with cjs/ and types/
swapped in before the ES module run the second one fails. npm test: 27 pass in 5.7 s.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
