get-proto 1.0.1

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/get-proto@1.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/get-proto@1.0.1

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:sha256:40d1bef46cdee594dd8eca75a06cd2ad75719dc9142360da03e923054044cfa8","contract":["getProto retrieves the prototype of a standard object literal","getProto returns null for an object created with null prototype","getProto traverses inheritance chain for custom prototype links","getProto resolves class instance and derived class prototype links","getProto retrieves built-in array and function prototypes","wrapper function checkPrototype matches direct getProto behavior"],"goal":"verify pkg:npm/get-proto@1.0.1","kind":"HOW","packages":["pkg:npm/get-proto@1.0.1"],"schemaVersion":1},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","ecosystem":"npm","os":"windows","osVersionBucket":"11","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/get-proto@1.0.1"],"schemaVersion":1,"verifierAdapter":"node-typescript@1"}

import getProto from 'get-proto';

/**
 * Retrieves the prototype of the provided object.
 * @param {object} obj
 * @returns {object | null}
 */
export function checkPrototype(obj) {
  return getProto(obj);
}

export default getProto;

{
  "name": "sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample",
      "version": "1.0.0",
      "dependencies": {
        "get-proto": "1.0.1"
      }
    },
    "node_modules/call-bind-apply-helpers": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
      "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
      "license": "MIT",
      "dependencies": {
        "es-errors": "^1.3.0",
        "function-bind": "^1.1.2"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/dunder-proto": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
      "integrity": "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A==",
      "license": "MIT",
      "dependencies": {
        "call-bind-apply-helpers": "^1.0.1",
        "es-errors": "^1.3.0",
        "gopd": "^1.2.0"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/es-errors": {
      "version": "1.3.0",
      "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/es-object-atoms": {
      "version": "1.1.2",
      "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.2.tgz",
      "integrity": "sha512-HWcBoN6NileqtSydK2FqHbS/LoDd2pqrnQHLyJzBj4kOp/ky2MWMN694xOfkK8/SnUsW2DH7EfyVlydKCsm1Zw==",
      "license": "MIT",
      "dependencies": {
        "es-errors": "^1.3.0"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/function-bind": {
      "version": "1.1.2",
      "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
      "license": "MIT",
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/get-proto": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/get-proto/-/get-proto-1.0.1.tgz",
      "integrity": "sha512-sTSfBjoXBp89JvIKIefqw7U2CCebsc74kiY6awiGogKtoSGbgjYE/G/+l9sF3MWFPNc9IcoOC4ODfKHfxFmp0g==",
      "license": "MIT",
      "dependencies": {
        "dunder-proto": "^1.0.1",
        "es-object-atoms": "^1.0.0"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/gopd": {
      "version": "1.2.0",
      "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.2.0.tgz",
      "integrity": "sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    }
  }
}

{
  "name": "sample",
  "version": "1.0.0",
  "type": "module",
  "dependencies": {
    "get-proto": "1.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/get-proto@1.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/get-proto@1.0.1"
  ]
}

import assert from 'node:assert/strict';
import getProto from 'get-proto';
import { checkPrototype } from '../index.mjs';

// Case 1: getProto retrieves the prototype of a standard object literal
{
  const obj = { foo: 'bar' };
  const proto = getProto(obj);
  assert.equal(proto, Object.prototype, 'prototype of standard object should be Object.prototype');
}

// Case 2: getProto returns null for an object created with null prototype
{
  const nullProtoObj = Object.create(null);
  const proto = getProto(nullProtoObj);
  assert.equal(proto, null, 'prototype of null-prototype object should be null');
}

// Case 3: getProto traverses inheritance chain for custom prototype links
{
  const parent = { role: 'base' };
  const child = Object.create(parent);
  assert.equal(getProto(child), parent, 'prototype of child should be parent object');
  assert.equal(getProto(parent), Object.prototype, 'prototype of parent should be Object.prototype');
}

// Case 4: getProto resolves class instance and derived class prototype links
{
  class BaseEntity {}
  class UserEntity extends BaseEntity {}

  const user = new UserEntity();
  assert.equal(getProto(user), UserEntity.prototype, 'instance prototype should be UserEntity.prototype');
  assert.equal(getProto(UserEntity.prototype), BaseEntity.prototype, 'UserEntity prototype should be BaseEntity.prototype');
  assert.equal(getProto(BaseEntity.prototype), Object.prototype, 'BaseEntity prototype should be Object.prototype');
  assert.equal(getProto(UserEntity), BaseEntity, 'UserEntity class constructor prototype should be BaseEntity');
}

// Case 5: getProto retrieves built-in array and function prototypes
{
  const list = [10, 20, 30];
  assert.equal(getProto(list), Array.prototype, 'prototype of array should be Array.prototype');

  const fn = function testFunction() {};
  assert.equal(getProto(fn), Function.prototype, 'prototype of function should be Function.prototype');
}

// Case 6: wrapper function checkPrototype matches direct getProto behavior
{
  const sampleObj = { greeting: 'hello' };
  assert.equal(checkPrototype(sampleObj), getProto(sampleObj), 'checkPrototype wrapper should match direct getProto');
}

console.log('PASS: all get-proto contract assertions passed');