Sample

Verify how @babel/preset-env resolves ES module transformation and dynamic imports across default auto mode, caller ESM capabilities, and explicit CommonJS or UMD targets

sha256:c4a33343c181512f335c90867036291efc6169df72e7fcf2cb0b89ddd867174f

PUBLISHED L3_CONTRACT_PASS MIT-0

Case

Goal: Verify how @babel/preset-env resolves ES module transformation and dynamic imports across default auto mode, caller ESM capabilities, and explicit CommonJS or UMD targets HOW
Packages: @babel/core 8.0.1 @babel/preset-env 8.0.2
Environment: node
Created: 2026-08-16T15:45:42Z

Commonly assumed

Default modules: 'auto' in @babel/preset-env transpiles ES module import and export declarations into CommonJS require and exports statements unless an explicit bundler caller signals supportsStaticESM: true.

The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.

Contract

Default modules: 'auto' preserves static ES module import and export declarations untouched in standard execution rather than compiling them to CommonJS require and exports.
Default modules: 'auto' still desugars export * as ns syntax unless caller explicitly declares supportsExportNamespaceFrom: true, while modules: false preserves export * as unconditionally.
Passing caller with supportsStaticESM: false triggers CommonJS module compilation for static imports and exports while keeping dynamic import native by default.
Configuring modules: 'commonjs' transforms both static imports and dynamic imports to CommonJS require unless transform-dynamic-import is explicitly excluded.
Configuring modules: 'umd' wraps static module syntax in UMD factory boilerplate while preserving native dynamic import expressions.

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

csx-seed

Verification receipts

node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-16 · ed25519:d91480838ac982c9