p-map 7.1.1: pMapSkip

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify p-map.pMapSkip in pkg:npm/p-map@7.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/p-map@7.1.1
Demonstrate these symbols/APIs:
  - p-map.pMapSkip

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:a1c050151396feef52ee8ad92cb35a1baffccdd0491de16c3d0cd08b419f8b15","contract":["pMapSkip is a Symbol('skip') sentinel exported by p-map","Returning pMapSkip from a pMap mapper omits that element from the resolved array while preserving input order","Returning pMapSkip from a pMapSettled mapper omits that element from the settled results array","Returning pMapSkip from a pMapIterable mapper skips yielding that element from the async iterable","Returning pMapSkip from a pMapKeyed or pMapSettledKeyed mapper omits the corresponding key or Map entry from the returned object or Map"],"goal":"verify p-map.pMapSkip in pkg:npm/p-map@7.1.1","kind":"HOW","packages":["pkg:npm/p-map@7.1.1"],"schemaVersion":1,"symbols":["p-map.pMapSkip"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/p-map@7.1.1"],"schemaVersion":1,"subject":"pkg:npm/p-map@7.1.1","symbols":["p-map.pMapSkip"],"verifierAdapter":"node-typescript@1"}

{
  "name": "p-map-skip-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "p-map-skip-sample",
      "version": "1.0.0",
      "dependencies": {
        "p-map": "7.1.1"
      }
    },
    "node_modules/p-map": {
      "version": "7.1.1",
      "resolved": "https://registry.npmjs.org/p-map/-/p-map-7.1.1.tgz",
      "integrity": "sha512-6Lh3jQPLthYujSrlw6ccWXBGZTkoTCz27Hd92g79LH/kjAbgoEu0t442cCCNbegPSJsA0lwDX8z0bcKtkpA32g==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    }
  }
}

{
  "name": "p-map-skip-sample",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "p-map": "7.1.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify p-map.pMapSkip in pkg:npm/p-map@7.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/p-map@7.1.1"
  ],
  "symbols": [
    "p-map.pMapSkip"
  ]
}

import assert from 'node:assert/strict';
import pMap, {pMapSkip, pMapSettled, pMapIterable, pMapKeyed, pMapSettledKeyed} from 'p-map';

assert.equal(typeof pMapSkip, 'symbol');
assert.equal(pMapSkip.description, 'skip');

// 1. pMap omits elements when mapper returns pMapSkip, preserving order of remaining elements
const mapped = await pMap([1, 2, 3, 4, 5], async (value, index) => {
	if (value % 2 === 0 || index === 4) {
		return pMapSkip;
	}
	return value * 10;
}, {concurrency: 2});
assert.deepEqual(mapped, [10, 30]);

// 2. pMapSettled omits skipped elements while retaining fulfilled and rejected statuses
const settled = await pMapSettled([1, 2, 3], async value => {
	if (value === 2) {
		return pMapSkip;
	}
	if (value === 3) {
		throw new Error('fail');
	}
	return value * 10;
});
assert.equal(settled.length, 2);
assert.deepEqual(settled[0], {status: 'fulfilled', value: 10});
assert.equal(settled[1].status, 'rejected');
assert.equal(settled[1].reason.message, 'fail');

// 3. pMapIterable skips yielding elements where mapper returns pMapSkip
const streamed = [];
for await (const item of pMapIterable([10, 20, 30, 40], async value => {
	return value === 20 || value === 40 ? pMapSkip : value + 1;
}, {concurrency: 2})) {
	streamed.push(item);
}
assert.deepEqual(streamed, [11, 31]);

// 4. pMapKeyed omits object keys and Map entries when mapper returns pMapSkip
const keyedObj = await pMapKeyed({a: 1, b: 2, c: 3}, async (value, key) => {
	return key === 'b' ? pMapSkip : value * 2;
});
assert.deepEqual(Object.keys(keyedObj), ['a', 'c']);
assert.equal(keyedObj.a, 2);
assert.equal(keyedObj.c, 6);
assert.equal('b' in keyedObj, false);

const keyedMap = await pMapKeyed(new Map([['x', 5], ['y', 6]]), async value => {
	return value === 5 ? pMapSkip : value * 3;
});
assert.equal(keyedMap instanceof Map, true);
assert.deepEqual([...keyedMap.entries()], [['y', 18]]);

// 5. pMapSettledKeyed omits keys when mapper returns pMapSkip
const settledKeyed = await pMapSettledKeyed({keep: 7, skip: 8}, async (value, key) => {
	return key === 'skip' ? pMapSkip : value;
});
assert.deepEqual(Object.keys(settledKeyed), ['keep']);
assert.deepEqual(settledKeyed.keep, {status: 'fulfilled', value: 7});
assert.equal('skip' in settledKeyed, false);