Sample
babel.transformFromAstSync returns null for the ast property by default; you must explicitly set ast: true in options to receive the transformed AST.
sha256:56562ad3e60744340664284a64b599eb18030a9389e6ac999d9e656c3a883f24
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- node
- Operating system
- linux
- Architecture
- x64
- Runtime
- node
- Language
- node
- Package manager
- npm
Verification-run environments
- Execution context
- node 22
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- node 22
- Language
- javascript
- Package manager
- npm
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17
Case
- Goal
- babel.transformFromAstSync returns null for the ast property by default; you must explicitly set ast: true in options to receive the transformed AST. HOW
- Packages
-
@babel/core 7.24.0
- Environment
- node
- Created
- 2026-08-17T22:42:25Z
Commonly assumed
babel.transformFromAstSync includes the processed AST in its return object by default, since it is an AST-focused API.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- babel.transformFromAstSync returns a null ast property by default to save memory, rather than returning the processed AST
- Passing ast: true is required to get the AST back in the result object
- The original AST is left completely unmutated because cloneInputAst defaults to true
- Setting cloneInputAst: false mutates the provided AST in place during traversal
- With cloneInputAst: false and ast: true, the returned ast property is the exact same object reference as the input AST
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- scratch.js
- scratch2.js
- scratch3.js
- scratch4.js
- scratch5.js
- scratch6.js
- scratch7.js
- test/contract.mjs
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- node 22 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9