Sample
Handle Puppeteer's current Uint8Array screenshot result safely in Node.js, or request base64 from Puppeteer explicitly.
sha256:76a3d81b76db62e83d80c16f85e5325d5c0fc7fdaee250313f250abe4832154f
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
- typescript 5.9
- 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:PASS · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17
Case
- Goal
- Handle Puppeteer's current Uint8Array screenshot result safely in Node.js, or request base64 from Puppeteer explicitly. HOW
- Packages
-
puppeteer 25.7.0
- Environment
- node
- Created
- 2026-08-17T03:53:06Z
Commonly assumed
On current Puppeteer, page.screenshot() returns a Node.js Buffer, so calling result.toString('base64') uses Buffer's encoding overload.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- TypeScript 5.9 accepts Puppeteer 25.7.0 page.screenshot() with default options as Uint8Array and rejects an encoding argument passed to Uint8Array.toString.
- TypeScript accepts page.screenshot({encoding: 'base64'}) as string.
- For binary screenshot bytes in Node.js, Uint8Array.toString('base64') returns comma-separated decimal bytes while Buffer.from(bytes).toString('base64') returns base64.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs
- test/types.ts
- tsconfig.json
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- node 22 · linux alpine/x64 · docker · CONTAINER_RUN · compile:PASS · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9