@vitest/utils 4.1.10: notNullish

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.notNullish 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.notNullish

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:ab9cd22d6f3536c61d496bb0fadb42a4176d9de9a1d3914df5a3b7ea7a208b99","contract":["notNullish returns false for null and undefined","notNullish returns true for falsy values including false, 0, -0, 0n, empty string, and NaN","notNullish returns true for truthy primitive values including non-empty strings, numbers, booleans, and symbols","notNullish returns true for objects, arrays, functions, and regex instances","notNullish acts as an array filter predicate removing only null and undefined while preserving other falsy values"],"goal":"verify @vitest/utils.notNullish in pkg:npm/%40vitest/utils@4.1.10","kind":"HOW","packages":["pkg:npm/%40vitest/utils@4.1.10"],"schemaVersion":1,"symbols":["@vitest/utils.notNullish"]},"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/%40vitest/utils@4.1.10"],"schemaVersion":1,"subject":"pkg:npm/%40vitest/utils@4.1.10","symbols":["@vitest/utils.notNullish"],"verifierAdapter":"node-typescript@1"}

import { notNullish } from '@vitest/utils/helpers';

export { notNullish };

export function filterNotNullish(items) {
  return items.filter(notNullish);
}

export function isNotNullish(value) {
  return notNullish(value);
}

{
  "name": "sample-vitest-utils-notnullish",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-vitest-utils-notnullish",
      "version": "1.0.0",
      "dependencies": {
        "@vitest/utils": "4.1.10"
      }
    },
    "node_modules/@vitest/pretty-format": {
      "version": "4.1.10",
      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.1.10.tgz",
      "integrity": "sha512-W1HsjSH4MXQ9YfmmhLAoIYf1HRfekQCGngeIgcei6MP5QQGWUe0gkopdZQaVCFO+JDJMrAJGwa5pRpNpvy4P8Q==",
      "license": "MIT",
      "dependencies": {
        "tinyrainbow": "^3.1.0"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
    "node_modules/@vitest/utils": {
      "version": "4.1.10",
      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.10.tgz",
      "integrity": "sha512-fy9am/HWxbaGt/Sawrp90vt6Y6jQwf1RX77cz3uwoJwJVMli/e1IEwRPnMNJ7vKfPTwo0diXifkpPvwH9v7nGA==",
      "license": "MIT",
      "dependencies": {
        "@vitest/pretty-format": "4.1.10",
        "convert-source-map": "^2.0.0",
        "tinyrainbow": "^3.1.0"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
    "node_modules/convert-source-map": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
      "integrity": "sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==",
      "license": "MIT"
    },
    "node_modules/tinyrainbow": {
      "version": "3.1.1",
      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.1.1.tgz",
      "integrity": "sha512-yau8yJdTt989Mm0Bd/236QnzEiPf2xLLTqUZRUJOo/3CB078LSwzei343DgtJVmfJKJE3TMINY1u42SQsP6mXw==",
      "license": "MIT",
      "engines": {
        "node": ">=14.0.0"
      }
    }
  }
}

{
  "name": "sample-vitest-utils-notnullish",
  "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.notNullish in pkg:npm/%40vitest/utils@4.1.10",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40vitest/utils@4.1.10"
  ],
  "symbols": [
    "@vitest/utils.notNullish"
  ]
}

import assert from 'node:assert/strict';
import { notNullish } from '@vitest/utils/helpers';
import { filterNotNullish, isNotNullish } from '../index.mjs';

// 1. notNullish returns false for null and undefined
{
  assert.equal(notNullish(null), false);
  assert.equal(notNullish(undefined), false);
  assert.equal(notNullish(void 0), false);
  assert.equal(isNotNullish(null), false);
  assert.equal(isNotNullish(undefined), false);
}

// 2. notNullish returns true for falsy values including false, 0, -0, 0n, empty string, and NaN
{
  assert.equal(notNullish(false), true);
  assert.equal(notNullish(0), true);
  assert.equal(notNullish(-0), true);
  assert.equal(notNullish(0n), true);
  assert.equal(notNullish(''), true);
  assert.equal(notNullish(NaN), true);
  assert.equal(isNotNullish(false), true);
  assert.equal(isNotNullish(0), true);
  assert.equal(isNotNullish(''), true);
  assert.equal(isNotNullish(NaN), true);
}

// 3. notNullish returns true for truthy primitive values including non-empty strings, numbers, booleans, and symbols
{
  assert.equal(notNullish('hello'), true);
  assert.equal(notNullish(42), true);
  assert.equal(notNullish(-1), true);
  assert.equal(notNullish(Infinity), true);
  assert.equal(notNullish(-Infinity), true);
  assert.equal(notNullish(true), true);
  assert.equal(notNullish(Symbol('id')), true);
  assert.equal(notNullish(123n), true);
  assert.equal(isNotNullish('hello'), true);
  assert.equal(isNotNullish(42), true);
  assert.equal(isNotNullish(true), true);
}

// 4. notNullish returns true for objects, arrays, functions, and regex instances
{
  assert.equal(notNullish({}), true);
  assert.equal(notNullish({ a: 1 }), true);
  assert.equal(notNullish(Object.create(null)), true);
  assert.equal(notNullish([]), true);
  assert.equal(notNullish([1, 2, 3]), true);
  assert.equal(notNullish(() => {}), true);
  assert.equal(notNullish(function test() {}), true);
  assert.equal(notNullish(/abc/i), true);
  assert.equal(notNullish(new Date()), true);
  assert.equal(isNotNullish({}), true);
  assert.equal(isNotNullish([]), true);
}

// 5. notNullish acts as an array filter predicate removing only null and undefined while preserving other falsy values
{
  const mixed = [0, null, 'hello', undefined, false, '', NaN, null, { key: 'value' }, []];
  const filtered = mixed.filter(notNullish);
  assert.equal(filtered.length, 7);
  assert.equal(filtered[0], 0);
  assert.equal(filtered[1], 'hello');
  assert.equal(filtered[2], false);
  assert.equal(filtered[3], '');
  assert.ok(Number.isNaN(filtered[4]));
  assert.deepEqual(filtered[5], { key: 'value' });
  assert.deepEqual(filtered[6], []);

  const helperFiltered = filterNotNullish(mixed);
  assert.equal(helperFiltered.length, 7);
  assert.equal(helperFiltered[0], 0);
  assert.equal(helperFiltered[1], 'hello');
  assert.equal(helperFiltered[2], false);
  assert.equal(helperFiltered[3], '');
  assert.ok(Number.isNaN(helperFiltered[4]));
}

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