Evidenceis-109

numericString gives true for string with spaces

is#109, at commit 05cdacc. A closed issue from a repository Credda did not choose.

LIVE2026-09-20

RIGHT_FAILURE

executed against the upstream checkout.

Outcome: REPRODUCED_NOT_DIAGNOSED
Wall time: 101.5s
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/is
Issue: #109
Pinned commit: 05cdaccf924c37b54f4fdd149caab5ebe2af2f1b

01The signal

The report, exactly as it was filed.

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

is#109 · as filedcommit 05cdacc

numericString gives true for string with spaces

This code  --
```js
is.numericString(' ');
is.numericString('     ');
```
returns true for both cases. 

I was expecting them to return false. Right now, the check is this --
```js
is.string(value) && value.length > 0 && !Number.isNaN(Number(value));
```
`Number` coerces whitespaces to 0 which is not taken into account right now.

I can make a PR if this was not the original intended behavior.

Repository: sindresorhus/is
Issue: #109
Commit: 05cdaccf924c37b54f4fdd149caab5ebe2af2f1b
Why this commit: The first parent of the fix commit 402fbb5a7e75ca478c135c4d8b6bf1e1ae34cce9, which GitHub binds to this issue via CLOSED_EVENT_COMMIT. 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: is.numericString(' ') produces true; the fix makes it produce false.
Expression: is.numericString(' ')
Reported output: true
Where that came from: Proposed by a model reading this report and nothing else -- it never saw the repository or the fix commit -- and read back as a claim by the same parser the harvest uses, SAME_LINE form: `is.numericString(' ') //=> true`. The report sat in the CODE_NO_ANNOTATION_AT_ALL bucket, which no regex reaches. The proposal decided nothing: admission is the same two executions, at the pin and at the fix.

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

`is.numericString(' ')` still produces true (read true)

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	`is.numericString(' ')` still produces true (read true)
right-failure	pass	Reproduced the reported failure: is.numericString(' ') produces true; the fix makes it produce false.
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 05cdacc, 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/is
git checkout 05cdaccf924c37b54f4fdd149caab5ebe2af2f1b
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