Sample
Verify object rest, object spread, and class field boundary semantics during transpilation with @babel/preset-env
sha256:3dd3092f04a6ac53892f1cadd9b07dda91bf5c7df33b77c73608d4ea639b2d0c
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Verify object rest, object spread, and class field boundary semantics during transpilation with @babel/preset-env HOW
- Packages
- @babel/preset-env 8.0.2 @babel/core 8.0.1
- Environment
- node
- Created
- 2026-08-16T17:21:08Z
Commonly assumed
Transpiling object rest destructuring and object spread with @babel/preset-env preserves accessor descriptors like getters and copies inherited prototype properties onto the resulting object.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Transpiling object rest destructuring and object spread with @babel/preset-env evaluates getters into plain data properties, drops inherited prototype properties and non-enumerable properties, but preserves own enumerable Symbol keys.
- Transpiled class instance spread creates a plain Object, stripping prototype methods, prototype getters, and class prototype identity.
- Transpiled subclass field initialization uses [[Define]] semantics via Object.defineProperty, creating an own property without invoking matching base class setters.
- Transpiling with explicit target environments desugars rest and spread syntax into _objectWithoutProperties and _objectSpread helper functions while retaining standard evaluation order and semantics.
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 · 2026-08-16 · ed25519:d91480838ac982c9