CodeSampleX

Sample

Promise.map with concurrency limit to transform async items

sha256:80c9caca5fc5ac442184f5a574ccd00d1e9fdc8c6ea49c69188a528350e2fdf0

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment node 22.23 linux 24 · ubuntu · glibc 2.39 x64 node 22.23 javascript npm 10

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…
2026-08-26

Case

HOW
Goal
Promise.map with concurrency limit to transform async items
Packages
Symbols
  • Promise.map
Environment
node 22.23.2
Created
2026-08-26T09:26:36Z

Contract

  1. Promise.map iterates over input items, applies async mapper, and resolves to array of transformed results in original order
  2. Promise.map enforces concurrency option so no more than specified number of mapper promises execute simultaneously
  3. Promise.map accepts input arrays containing Promises or mixed values and resolves items before passing to mapper
  4. Promise.map rejects immediately when any mapper operation throws or returns a rejected promise
  5. Promise.map handles empty iterable resolving immediately to empty array without invoking mapper
  6. Promise.map passes current item index and total array length to mapper callback

Files

  • PROMPT.md
  • csx.json
  • index.mjs
  • package-lock.json
  • package.json
  • spec.json
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

anonymous