@vitest/utils 4.1.10: getSafeTimers

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 @vitest/utils.getSafeTimers in pkg:npm/%40vitest/utils@4.1.10
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40vitest/utils@4.1.10
Demonstrate these symbols/APIs:
  - @vitest/utils.getSafeTimers

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.

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import { getSafeTimers, setSafeTimers, delay } from '@vitest/utils/timers';

export { getSafeTimers, setSafeTimers, delay };

export function createSafeScheduler() {
  const timers = getSafeTimers();
  return {
    setTimeout: timers.setTimeout,
    clearTimeout: timers.clearTimeout,
    delay: (ms) => delay(ms, timers.setTimeout),
  };
}

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  "name": "sample-vitest-utils-getsafetimers",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-vitest-utils-getsafetimers",
      "version": "1.0.0",
      "dependencies": {
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      }
    },
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      "license": "MIT",
      "dependencies": {
        "tinyrainbow": "^3.1.0"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
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      "version": "4.1.10",
      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.10.tgz",
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      "dependencies": {
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        "tinyrainbow": "^3.1.0"
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      "funding": {
        "url": "https://opencollective.com/vitest"
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    },
    "node_modules/convert-source-map": {
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      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
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      "license": "MIT"
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    "node_modules/tinyrainbow": {
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      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.1.1.tgz",
      "integrity": "sha512-yau8yJdTt989Mm0Bd/236QnzEiPf2xLLTqUZRUJOo/3CB078LSwzei343DgtJVmfJKJE3TMINY1u42SQsP6mXw==",
      "license": "MIT",
      "engines": {
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}

{
  "name": "sample-vitest-utils-getsafetimers",
  "version": "1.0.0",
  "type": "module",
  "main": "index.mjs",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "@vitest/utils": "4.1.10"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @vitest/utils.getSafeTimers in pkg:npm/%40vitest/utils@4.1.10",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40vitest/utils@4.1.10"
  ],
  "symbols": [
    "@vitest/utils.getSafeTimers"
  ]
}

import assert from 'node:assert/strict';
import { getSafeTimers, setSafeTimers, delay } from '@vitest/utils/timers';
import { createSafeScheduler } from '../index.mjs';

// 1. getSafeTimers returns standard timer and scheduling functions
{
  const timers = getSafeTimers();
  assert.equal(typeof timers, 'object');
  assert.notEqual(timers, null);
  assert.equal(typeof timers.setTimeout, 'function');
  assert.equal(typeof timers.setInterval, 'function');
  assert.equal(typeof timers.clearTimeout, 'function');
  assert.equal(typeof timers.clearInterval, 'function');
  assert.equal(typeof timers.setImmediate, 'function');
  assert.equal(typeof timers.clearImmediate, 'function');
  assert.equal(typeof timers.nextTick, 'function');
  assert.equal(typeof timers.queueMicrotask, 'function');
}

// 2. getSafeTimers defaults to global timers before setSafeTimers is invoked
{
  // In a clean environment without SAFE_TIMERS_SYMBOL set, getSafeTimers returns global functions
  const timers = getSafeTimers();
  assert.equal(timers.setTimeout, globalThis.setTimeout);
  assert.equal(timers.setInterval, globalThis.setInterval);
  assert.equal(timers.clearTimeout, globalThis.clearTimeout);
  assert.equal(timers.clearInterval, globalThis.clearInterval);
  assert.equal(timers.setImmediate, globalThis.setImmediate);
  assert.equal(timers.clearImmediate, globalThis.clearImmediate);
  assert.equal(timers.queueMicrotask, globalThis.queueMicrotask);
  assert.equal(timers.nextTick, globalThis.process.nextTick);
}

// 3. getSafeTimers preserves original timer implementations after setSafeTimers snapshot and global mocking
{
  const originalSetTimeout = globalThis.setTimeout;
  const originalClearTimeout = globalThis.clearTimeout;

  // Snapshot current timers into the safe timers symbol
  setSafeTimers();

  // Mock global timers
  let mockSetTimeoutCalled = false;
  globalThis.setTimeout = function mockSetTimeout() {
    mockSetTimeoutCalled = true;
    return 999;
  };
  globalThis.clearTimeout = function mockClearTimeout() {};

  try {
    const safe = getSafeTimers();

    // getSafeTimers returns the captured snapshot, not the mocked global functions
    assert.equal(safe.setTimeout, originalSetTimeout);
    assert.notEqual(safe.setTimeout, globalThis.setTimeout);
    assert.equal(safe.clearTimeout, originalClearTimeout);
    assert.notEqual(safe.clearTimeout, globalThis.clearTimeout);

    // Calling global setTimeout triggers mock, but safe does not
    globalThis.setTimeout(() => {});
    assert.equal(mockSetTimeoutCalled, true);
  } finally {
    // Restore global functions
    globalThis.setTimeout = originalSetTimeout;
    globalThis.clearTimeout = originalClearTimeout;
  }
}

// 4. safe timer scheduling functions execute callbacks asynchronously
{
  const safe = getSafeTimers();
  let timeoutFired = false;
  let nextTickFired = false;
  let microtaskFired = false;

  await new Promise((resolve) => {
    safe.nextTick(() => {
      nextTickFired = true;
    });

    safe.queueMicrotask(() => {
      microtaskFired = true;
    });

    safe.setTimeout(() => {
      timeoutFired = true;
      resolve();
    }, 10);
  });

  assert.equal(nextTickFired, true);
  assert.equal(microtaskFired, true);
  assert.equal(timeoutFired, true);

  // Test via delay with safe scheduler
  const scheduler = createSafeScheduler();
  const startTime = Date.now();
  await scheduler.delay(15);
  const elapsed = Date.now() - startTime;
  assert.ok(elapsed >= 10, `Expected elapsed >= 10ms, got ${elapsed}ms`);
}

// 5. safe clearTimeout successfully cancels pending timer scheduled with safe setTimeout
{
  const safe = getSafeTimers();
  let cancelledFired = false;

  const timerId = safe.setTimeout(() => {
    cancelledFired = true;
  }, 20);

  safe.clearTimeout(timerId);

  // Wait long enough to ensure the cancelled timer does not fire
  await delay(40, safe.setTimeout);

  assert.equal(cancelledFired, false);
}

console.log('All @vitest/utils getSafeTimers contract assertions passed.');