Sample
core-js 3.42.0: Demonstrate that core-js/configurator overrides polyfill aggressiveness via usePolyfill, useNative, and useFeatureDetection, and that useNative still installs polyfills for undefined features.
Verified sample for npm core-js 3.42.0: Demonstrate that core-js/configurator overrides polyfill aggressiveness via usePolyfill, useNative, and…
sha256:e5be7751aab154725b5932787866e2f8beb21e17e99d2d2d8e5ba395c71f8f2c
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
node linux x64 node node npm
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-18 |
| node 22 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-18 |
Case
HOW- Goal
- Demonstrate that core-js/configurator overrides polyfill aggressiveness via usePolyfill, useNative, and useFeatureDetection, and that useNative still installs polyfills for undefined features.
- Packages
- Symbols
-
- core-js/configurator
- Environment
- node
- Created
- 2026-08-18T00:52:08Z
Contract
- Calling core-js/configurator with usePolyfill forces replacement of compliant native methods upon module import, whereas useNative preserves native implementations but still installs polyfills when the target property is undefined.
- usePolyfill with Array.prototype.toReversed replaces the native implementation.
- Normalization accepts Array#findLast and array.findlastindex interchangeably.
- useNative with structuredClone preserves the native structuredClone implementation.
- useFeatureDetection resets earlier forced aggressiveness overrides back to feature detection.
- useNative with Iterator.range installs the polyfill when the native property is absent.
- Calling configurator after a module has already been imported does not retroactively replace already-evaluated methods.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs