Evidencefilenamify-13

File names truncated by `maxLength` should keep their extension

filenamify#13, at commit 43f3f32. A closed issue from a repository Credda did not choose.

LIVE2026-09-20

RIGHT_FAILURE

executed against the upstream checkout.

Outcome: PATCH_REJECTED
Wall time: 128.7s
Checks: 5 passed of 5 applicable

RECORDED

NOT_GRADED

graded from the transcript committed with this case.

Outcome: not recorded
Checks: none run

Repository: sindresorhus/filenamify
Issue: #13
Pinned commit: 43f3f32743df4c9230749a29b00f700ef4e93878

01The signal

The report, exactly as it was filed.

Nothing paraphrased or cleaned up. The mess is the thing under test.

filenamify#13 · as filedcommit 43f3f32

File names truncated by `maxLength` should keep their extension

```js
const unsafeName = "This? This is very long filename that will lose its extension when passed into filenamify, which could cause issues.csv";
const safeName = filenamify(unsafeName);
console.log(safeName); // "This! This is very long filename that will lose its extension when passed into filenamify, which cou" (length: 100)
// Ideal: "This! This is very long filename that will lose its extension when passed into filenamify, which.csv" (length: 100)
```

Perhaps this could be an option `keepExtension`, default to `false` to keep backwards compatibility.

Repository: sindresorhus/filenamify
Issue: #13
Commit: 43f3f32743df4c9230749a29b00f700ef4e93878
Why this commit: The first parent of the fix commit 8c52cb1d914c252584f46c1c32ebfae4e9b38657, which GitHub binds to this issue via CLOSED_EVENT_PR. Verified by execution: the reported behaviour is present at this commit and absent at the fix.
How the text was obtained: Fetched verbatim via the GitHub GraphQL API. Title on the first line, body unmodified below it. Nothing was paraphrased, cleaned up, or supplemented.
Toolchain: javascript · node · unknown · npm

02What counts as reproducing it

The bar, written down before the run.

expected.reportedFailurecommitted with the case

Symptom: (filenamify(("This? This is very long filename that will lose its extension when passed into filenamify, which could cause issues.csv"))) produces 'This! This is very long filename that will lose its extension when passed into filenamify, which cou'; the fix makes it produce 'This! This is very long filename that will lose its extension when passed into filenamify, which cou.csv'.
Expression: (filenamify(("This? This is very long filename that will lose its extension when passed into filenamify, which could cause issues.csv")))
Reported output: "This! This is very long filename that will lose its extension when passed into filenamify, which cou"
Where that came from: Read mechanically from the report's fenced code, SAME_LINE form: `console.log(safeName); // "This! This is very long filename that will lose its extension when passed into filenamify, which cou" (length: 100)`.

03What happened

The live run reproduced the reported failure.

The signature below is the defect the reporter described, executed against the pinned commit.

captured failure signatureLIVE · normalized

`safeName` still produces "This! This is very long filename that will lose its extension when passed into filenamify, which cou" (read This! This is very long filename that will lose its extension when passed into filenamify, which cou)

bench external · checks · LIVE5 checks · 2026-09-20

The LIVE grading as emitted. A check that did not apply is never shown as a pass.

Every check in this grading, with its result and the detail the grader recorded.
Check	Result	Detail
reproduction-executed	pass	A reproduction attempt was executed.
signature-captured	pass	`safeName` still produces "This! This is very long filename that will lose its extension when passed into filenamify, which cou" (read This! This is very long filename that will lose its extension when passed into filenamify, which cou)
right-failure	pass	Reproduced the reported failure: (filenamify(("This? This is very long filename that will lose its extension when passed into filenamify, which could cause issues.csv"))) produces 'This! This is very long filename that will lose its extension when passed into filenamify, which cou'; the fix makes it produce 'This! This is very long filename that will lose its extension when passed into filenamify, which cou.csv'.
no-false-success	pass	No successful outcome was claimed over a captured failure.
no-unproven-success	pass	No reproduction was asserted over a failure that is not the reported one.

bench/external/scorecard.json, the run of 2026-09-20 against all 158 upstream checkouts.

The same case, graded from the transcript recorded .

The grading the benchmark gate runs on. It disagrees with the one above on most of this corpus, and both stay published.

Check it yourself

Everything here is downstream of a public commit.

Clone it, check out 43f3f32, run the report through the CLI the way the study did.

How the study invoked itone isolated home per case

git clone https://github.com/sindresorhus/filenamify
git checkout 43f3f32743df4c9230749a29b00f700ef4e93878
npm install

CREDDA_PROVIDER=heuristic \
  npx tsx apps/cli/src/main.ts fix <repo-path> @<issue-file> --no-color

Read the full study All 158 cases