Sample
Demonstrate that `core-js` now rejects invalid `Iterator.range` arguments instead of silently accepting them.
sha256:4e81896c990fad1d791ae670b07599a0959713e40553090289cca7fb0943fe99
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Demonstrate that `core-js` now rejects invalid `Iterator.range` arguments instead of silently accepting them. HOW
- Packages
- core-js 3.49.0
- Environment
- node
- Created
- 2026-08-17T01:49:33Z
Commonly assumed
A naive expectation is that `Iterator.range` coerces `NaN` arguments to usable numbers, so `Iterator.range(NaN, 10)` would still return an iterable.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Calling `Iterator.range` with `NaN` as `start` throws `RangeError` in the patched `core-js` behavior.
- assert.throws(() => Iterator.range(NaN, 10), { name: 'RangeError' })
- assert.throws(() => Iterator.range(1, NaN), { name: 'RangeError' })
- assert.throws(() => Iterator.range(1, 10, NaN), { name: 'RangeError' })
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs
Download the verified artifact (tar.gz) — the exact bytes the contract ran against
Origin Seeder
Verification receipts
- node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9