Sample
core-js 3.50.0: Demonstrate that core-js 3.50 captures the built-in URL.prototype.toString when installing a missing URL.prototype.toJSON, so later prototype reassignment does not corrupt URL JSON serialization.
Verified sample for npm core-js 3.50.0: Demonstrate that core-js 3.50 captures the built-in URL.prototype.toString when installing a missing…
sha256:771727fb4ca310f83f1ec90c4a2f32315fedc9adae20af901d39e2e339f493f2
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 |
2026-08-17 |
| 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 3.50 captures the built-in URL.prototype.toString when installing a missing URL.prototype.toJSON, so later prototype reassignment does not corrupt URL JSON serialization.
- Packages
- Symbols
-
- core-js/actual/url
- URL.prototype.toJSON
- URL.prototype.toString
- URL.prototype.pathname
- Environment
- node
- Created
- 2026-08-17T01:49:38Z
Contract
- When the host URL.prototype.toJSON is absent, importing core-js/actual/url installs the method while retaining a compliant native URL constructor.
- The installed toJSON serializes an opaque mailto URL as mailto:sample-user and its pathname remains sample-user.
- After URL.prototype.toString is reassigned, String(url) observes the replacement but url.toJSON() still returns the original serialized URL.
Files
- csx.json
- package-lock.json
- package.json
- test/contract.cjs