bluebird 3.7.2: delay

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 bluebird.delay in pkg:npm/bluebird@3.7.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/bluebird@3.7.2
Demonstrate these symbols/APIs:
  - bluebird.delay
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:sha256:0a7aa21675f2cebd3557be8d14dacb4d84259b2bf34ce9b83ca728b906eeeb2d","constraints":{"executionContext":"node"},"contract":["assert Promise.delay returns a Promise that resolves with undefined after specified milliseconds","assert Promise.delay resolves with provided value after specified delay","assert Promise.delay waits for a promise value to resolve before delaying","assert Promise instance .delay(ms) delays fulfillment of existing promise","assert Promise instance .delay(ms) does not delay rejection when base promise rejects"],"goal":"verify bluebird.delay in pkg:npm/bluebird@3.7.2","kind":"HOW","packages":["pkg:npm/bluebird@3.7.2"],"schemaVersion":1,"symbols":["bluebird.delay"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/bluebird@3.7.2"],"schemaVersion":1,"subject":"pkg:npm/bluebird@3.7.2","symbols":["bluebird.delay"],"verifierAdapter":"node-typescript@1"}

import Promise from 'bluebird';

/**
 * Creates a promise that resolves after the specified number of milliseconds with an optional value.
 * @template T
 * @param {number} ms
 * @param {T|Promise<T>} [value]
 * @returns {Promise<T>}
 */
export function delay(ms, value) {
  return Promise.delay(ms, value);
}

export default Promise;

{
  "name": "sample-bluebird-delay",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-bluebird-delay",
      "version": "1.0.0",
      "dependencies": {
        "bluebird": "3.7.2"
      }
    },
    "node_modules/bluebird": {
      "version": "3.7.2",
      "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.7.2.tgz",
      "integrity": "sha512-XpNj6GDQzdfW+r2Wnn7xiSAd7TM3jzkxGXBGTtWKuSXv1xUV+azxAm8jdWZN06QTQk+2N2XB9jRDkvbmQmcRtg==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-bluebird-delay",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "dependencies": {
    "bluebird": "3.7.2"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify bluebird.delay in pkg:npm/bluebird@3.7.2",
  "kind": "HOW",
  "packages": [
    "pkg:npm/bluebird@3.7.2"
  ],
  "symbols": [
    "bluebird.delay"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import Promise, { delay } from '../index.mjs';

// 1. assert Promise.delay returns a Promise that resolves with undefined after specified milliseconds
{
  const t0 = Date.now();
  const res = await Promise.delay(20);
  const elapsed = Date.now() - t0;

  assert.strictEqual(res, undefined);
  assert.ok(elapsed >= 15, `Expected elapsed >= 15ms, got ${elapsed}ms`);
  assert.ok(Promise.delay(10) instanceof Promise, 'Expected instance of Promise');

  // Test helper
  const helperRes = await delay(10);
  assert.strictEqual(helperRes, undefined);
}

// 2. assert Promise.delay resolves with provided value after specified delay
{
  const res = await Promise.delay(20, 'custom-value');
  assert.strictEqual(res, 'custom-value');

  const helperRes = await delay(15, 42);
  assert.strictEqual(helperRes, 42);
}

// 3. assert Promise.delay waits for a promise value to resolve before delaying
{
  const t0 = Date.now();
  const innerPromise = Promise.delay(20, 'delayed-resolution');
  const res = await Promise.delay(20, innerPromise);
  const elapsed = Date.now() - t0;

  assert.strictEqual(res, 'delayed-resolution');
  assert.ok(elapsed >= 35, `Expected elapsed >= 35ms, got ${elapsed}ms`);
}

// 4. assert Promise instance .delay(ms) delays fulfillment of existing promise
{
  const t0 = Date.now();
  const res = await Promise.resolve(100).delay(25);
  const elapsed = Date.now() - t0;

  assert.strictEqual(res, 100);
  assert.ok(elapsed >= 20, `Expected elapsed >= 20ms, got ${elapsed}ms`);
}

// 5. assert Promise instance .delay(ms) does not delay rejection when base promise rejects
{
  const t0 = Date.now();
  let caught = null;
  try {
    await Promise.reject(new Error('immediate rejection')).delay(100);
  } catch (err) {
    caught = err;
  }
  const elapsed = Date.now() - t0;

  assert.ok(caught instanceof Error, 'Expected caught error');
  assert.strictEqual(caught.message, 'immediate rejection');
  assert.ok(elapsed < 50, `Expected immediate rejection (<50ms), took ${elapsed}ms`);
}

console.log('All bluebird.delay contract assertions passed.');