Sample

Prevent silent loss of AST modifications and missing AST results in @babel/core transformFromAstSync

sha256:9843a6619f29d4771b0ea7422ee91f41aed92d821140d6e877a16dc292949c9e

Case

Goal

Prevent silent loss of AST modifications and missing AST results in @babel/core transformFromAstSync HOW

Packages

@babel/core 8.0.1

Environment

node

Created

2026-08-17T01:44:28Z

Commonly assumed

transformFromAstSync modifies the provided AST object in place during traversal and populates result.ast with the transformed tree.

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

Contract

• transformFromAstSync preserves the input AST node unmodified and sets result.ast to null unless cloneInputAst is set to false and ast is set to true.
• inputAst.program.body[0].kind remains 'let' when cloneInputAst defaults to true
• defaultResult.ast is strictly null on default invocations
• cloneInputAst: false mutates the passed AST in place, changing kind to 'const'
• explicitResult.ast returns the root File AST node only when options.ast is explicitly true

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 · 2026-08-17 · ed25519:d91480838ac982c9