Sample
Leaving the modules option unset in @babel/preset-env defaults to auto, preserving ESM syntax when caller.supportsStaticESM is true and converting to CommonJS when false.
sha256:0e5c41047e8f368cb12ecb51f5efc04ac1bc1078de279411af5aee5b26a6cb52
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
- Leaving the modules option unset in @babel/preset-env defaults to auto, preserving ESM syntax when caller.supportsStaticESM is true and converting to CommonJS when false. HOW
- Packages
-
@babel/preset-env 8.0.2
- Environment
- node
- Created
- 2026-08-17T06:38:17Z
Commonly assumed
@babel/preset-env defaults the modules option to commonjs, unconditionally transforming import statements into require calls regardless of caller capabilities.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- When the modules option is left unset, @babel/preset-env defaults to 'auto' and preserves static import and export declarations unchanged when caller.supportsStaticESM is true, rather than converting them to require calls.
- When the modules option is left unset with caller.supportsStaticESM set to false, @babel/preset-env transpiles ESM imports into CommonJS require calls and exports.
- Explicitly setting modules to 'commonjs' forces transformation to require calls even when caller.supportsStaticESM is true.
- Explicitly setting modules to false preserves ESM import statements even when caller.supportsStaticESM is false.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- 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