co 4.6.0: execute generator function yielding promises using co

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: execute generator function yielding promises using co
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/co@4.6.0
Demonstrate these symbols/APIs:
  - co

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:cc7f7f07cf05e9f81195a1ae852b2bed8dc8791e90cec7a2e8a90b4adda88a35","contract":["co(fn*) executes generator and resolves sequential yielded promises to return value","co(fn*) resolves arrays of yielded promises concurrently","co(fn*) propagates rejections from yielded promises as error rejections"],"goal":"execute generator function yielding promises using co","kind":"HOW","packages":["pkg:npm/co@4.6.0"],"schemaVersion":1,"symbols":["co"]},"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/co@4.6.0"],"schemaVersion":1,"subject":"pkg:npm/co@4.6.0","symbols":["co"],"verifierAdapter":"node-typescript@1"}

import co from 'co';

export function runGenerator(generatorFn) {
  return co(generatorFn);
}

{
  "name": "sample-co-generator-runner",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-co-generator-runner",
      "version": "1.0.0",
      "dependencies": {
        "co": "4.6.0"
      }
    },
    "node_modules/co": {
      "version": "4.6.0",
      "resolved": "https://registry.npmjs.org/co/-/co-4.6.0.tgz",
      "integrity": "sha512-QVb0dM5HvG+uaxitm8wONl7jltx8dqhfU33DcqtOZcLSVIKSDDLDi7+0LbAKiyI8hD9u42m2YxXSkMGWThaecQ==",
      "license": "MIT",
      "engines": {
        "iojs": ">= 1.0.0",
        "node": ">= 0.12.0"
      }
    }
  }
}

{
  "name": "sample-co-generator-runner",
  "version": "1.0.0",
  "type": "module",
  "dependencies": {
    "co": "4.6.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "execute generator function yielding promises using co",
  "kind": "HOW",
  "packages": [
    "pkg:npm/co@4.6.0"
  ],
  "symbols": [
    "co"
  ]
}

import assert from 'node:assert/strict';
import co from 'co';

async function testCoExecution() {
  const result = await co(function* () {
    const a = yield Promise.resolve(10);
    const b = yield Promise.resolve(20);
    return a + b;
  });
  assert.equal(result, 30, 'co should resolve yielded promises sequentially');

  const arrayResult = await co(function* () {
    const res = yield [
      Promise.resolve(1),
      Promise.resolve(2),
      Promise.resolve(3)
    ];
    return res;
  });
  assert.deepEqual(arrayResult, [1, 2, 3], 'co should resolve arrays of promises in parallel');

  let errorCaught = false;
  try {
    await co(function* () {
      yield Promise.reject(new Error('yield error'));
    });
  } catch (err) {
    errorCaught = true;
    assert.equal(err.message, 'yield error');
  }
  assert.equal(errorCaught, true, 'co should reject when a yielded promise rejects');

  console.log('Contract tests passed successfully.');
}

testCoExecution();