deep-is 0.1.4

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 pkg:npm/deep-is@0.1.4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/deep-is@0.1.4
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - 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:sha256:91828b0edbdea457f77f451668c1776cd5034b5dffa3c83247832687d75bd488","constraints":{"executionContext":"node"},"contract":["deepIs returns true for identical primitives and false for distinct primitives","deepIs treats NaN as equal to NaN in scalar and nested structures","deepIs distinguishes positive zero and negative zero unlike standard equality","deepIs evaluates Date instances by their timestamps","deepIs evaluates nested arrays recursively","deepIs evaluates nested objects regardless of key order","deepIs correctly handles arguments objects and structural type mismatches"],"goal":"verify pkg:npm/deep-is@0.1.4","kind":"HOW","packages":["pkg:npm/deep-is@0.1.4"],"schemaVersion":1},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/deep-is@0.1.4"],"schemaVersion":1,"subject":"pkg:npm/deep-is@0.1.4","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-deep-is",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-deep-is",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "deep-is": "0.1.4"
      }
    },
    "node_modules/deep-is": {
      "version": "0.1.4",
      "resolved": "https://registry.npmjs.org/deep-is/-/deep-is-0.1.4.tgz",
      "integrity": "sha512-oIPzksmTg4/MriiaYGO+okXDT7ztn/w3Eptv/+gSIdMdKsJo0u4CfYNFJPy+4SKMuCqGw2wxnA+URMg3t8a/bQ==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-deep-is",
  "version": "1.0.0",
  "description": "verify pkg:npm/deep-is@0.1.4",
  "main": "src/index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "deep-is": "0.1.4"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/deep-is@0.1.4",
  "kind": "HOW",
  "packages": [
    "pkg:npm/deep-is@0.1.4"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "runtime": "node@22.23.2"
  }
}

'use strict';

const deepIs = require('deep-is');

/**
 * Compare two values for deep equality according to the deep-is algorithm.
 *
 * @param {*} actual - The value to test.
 * @param {*} expected - The expected value.
 * @returns {boolean} True if values are deeply equal, false otherwise.
 */
function isEqual(actual, expected) {
  return deepIs(actual, expected);
}

module.exports = {
  deepIs,
  isEqual
};

'use strict';

const assert = require('assert');
const { deepIs, isEqual } = require('../src/index');

// 1. Module export verification
{
  assert.strictEqual(typeof deepIs, 'function');
  assert.strictEqual(typeof isEqual, 'function');
}

// 2. deepIs returns true for identical primitives and false for distinct primitives
{
  assert.strictEqual(deepIs(1, 1), true);
  assert.strictEqual(deepIs('hello', 'hello'), true);
  assert.strictEqual(deepIs(true, true), true);
  assert.strictEqual(deepIs(null, null), true);
  assert.strictEqual(deepIs(undefined, undefined), true);
  assert.strictEqual(deepIs(1, 2), false);
  assert.strictEqual(deepIs('a', 'b'), false);
  assert.strictEqual(deepIs(true, false), false);
  assert.strictEqual(deepIs(null, undefined), false);
}

// 3. deepIs treats NaN as equal to NaN in scalar and nested structures
{
  assert.strictEqual(deepIs(NaN, NaN), true);
  assert.strictEqual(isEqual(NaN, NaN), true);
  assert.strictEqual(deepIs([NaN], [NaN]), true);
  assert.strictEqual(deepIs({ value: NaN }, { value: NaN }), true);
}

// 4. deepIs distinguishes positive zero and negative zero unlike standard equality
{
  assert.strictEqual(deepIs(0, 0), true);
  assert.strictEqual(deepIs(-0, -0), true);
  assert.strictEqual(deepIs(0, -0), false);
  assert.strictEqual(deepIs(-0, 0), false);
  assert.strictEqual(deepIs([0], [-0]), false);
  assert.strictEqual(deepIs({ num: 0 }, { num: -0 }), false);
}

// 5. deepIs evaluates Date instances by their timestamps
{
  const d1 = new Date(1700000000000);
  const d2 = new Date(1700000000000);
  const d3 = new Date(1700000000001);
  assert.strictEqual(deepIs(d1, d2), true);
  assert.strictEqual(deepIs(d1, d3), false);
}

// 6. deepIs evaluates nested arrays recursively
{
  assert.strictEqual(deepIs([1, 2, 3], [1, 2, 3]), true);
  assert.strictEqual(deepIs([1, [2, [3]]], [1, [2, [3]]]), true);
  assert.strictEqual(deepIs([1, 2, 3], [1, 2, 4]), false);
  assert.strictEqual(deepIs([1, 2], [1, 2, 3]), false);
}

// 7. deepIs evaluates nested objects regardless of key order
{
  assert.strictEqual(deepIs({ a: 1, b: 2 }, { b: 2, a: 1 }), true);
  assert.strictEqual(
    deepIs({ x: { y: 'nested', z: 42 } }, { x: { z: 42, y: 'nested' } }),
    true
  );
  assert.strictEqual(deepIs({ a: 1, b: 2 }, { a: 1, b: 3 }), false);
  assert.strictEqual(deepIs({ a: 1 }, { a: 1, b: undefined }), false);
}

// 8. deepIs correctly handles arguments objects and structural type mismatches
{
  function getArgs() {
    return arguments;
  }
  const args1 = getArgs(1, 2, 3);
  const args2 = getArgs(1, 2, 3);
  assert.strictEqual(deepIs(args1, args2), true);
  assert.strictEqual(deepIs(args1, [1, 2, 3]), false);
  assert.strictEqual(deepIs(null, {}), false);
  assert.strictEqual(deepIs({}, null), false);
}

console.log('All deep-is contract tests passed.');