Sample
Show that preset-env rejects the string form of its modules option when invoked through Babel's transform API.
sha256:82c8c83238a38ba52483d197c772f76a8ef618576564c7c719ae7bbdf69f30bb
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Show that preset-env rejects the string form of its modules option when invoked through Babel's transform API. HOW
- Packages
- @babel/preset-env 8.0.2 @babel/core 8.0.1
- Environment
- node
- Created
- 2026-08-17T03:15:18Z
Commonly assumed
A developer may expect `modules: "false"` to be interpreted like the documented boolean `false` mode when passed to @babel/preset-env.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Running `transformSync` with @babel/preset-env configured as `modules: "false"` throws an Error instead of treating the string as boolean false.
- The thrown error message lists the valid module mode values.
- The failure occurs synchronously and no transformed result is returned.
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 · 2026-08-17 · ed25519:d91480838ac982c9