pathval 2.0.1: setPathValue

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 setPathValue in pkg:npm/pathval@2.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/pathval@2.0.1
Demonstrate these symbols/APIs:
  - setPathValue

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:b5ea6feca41c2580d586c39c1fdc45b80693f4bb39c5d010eb4480da22469740","contract":["setPathValue sets root and nested object properties by string path","setPathValue creates intermediate objects when path segments do not exist","setPathValue creates intermediate arrays when next segment is an array index","setPathValue mutates and returns the target object","setPathValue handles escaped delimiters in property keys","setPathValue ignores unsafe prototype keys to prevent prototype pollution"],"goal":"verify setPathValue in pkg:npm/pathval@2.0.1","kind":"HOW","packages":["pkg:npm/pathval@2.0.1"],"schemaVersion":1,"symbols":["setPathValue"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/pathval@2.0.1"],"schemaVersion":1,"subject":"pkg:npm/pathval@2.0.1","symbols":["setPathValue"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-pathval-setpathvalue",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pathval-setpathvalue",
      "version": "1.0.0",
      "dependencies": {
        "pathval": "2.0.1"
      }
    },
    "node_modules/pathval": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/pathval/-/pathval-2.0.1.tgz",
      "integrity": "sha512-//nshmD55c46FuFw26xV/xFAaB5HF9Xdap7HJBBnrKdAd6/GxDBaNA1870O79+9ueg61cZLSVc+OaFlfmObYVQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 14.16"
      }
    }
  }
}

{
  "name": "sample-pathval-setpathvalue",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of setPathValue in pathval",
  "type": "module",
  "main": "src/index.js",
  "dependencies": {
    "pathval": "2.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify setPathValue in pkg:npm/pathval@2.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pathval@2.0.1"
  ],
  "symbols": [
    "setPathValue"
  ]
}

import { setPathValue } from 'pathval';

/**
 * Sets a value at a specified path on the target object.
 *
 * @param {object} obj - The target object to mutate.
 * @param {string} path - The string path (e.g. 'user.profile.name' or 'items[0]').
 * @param {*} value - The value to assign.
 * @returns {object} The mutated target object.
 */
export function setValue(obj, path, value) {
  return setPathValue(obj, path, value);
}

export { setPathValue };

import assert from 'node:assert';
import { setPathValue, setValue } from '../src/index.js';

// 1. Function exports verification
assert.strictEqual(typeof setPathValue, 'function', 'setPathValue must be a function');
assert.strictEqual(typeof setValue, 'function', 'setValue helper must be a function');

// 2. setPathValue sets root and nested object properties by string path
const obj1 = {};
const ret1 = setPathValue(obj1, 'name', 'Alice');
assert.strictEqual(ret1, obj1, 'setPathValue returns the target object');
assert.strictEqual(obj1.name, 'Alice');

setPathValue(obj1, 'address.city', 'Wonderland');
assert.strictEqual(obj1.address.city, 'Wonderland');

// 3. setPathValue creates intermediate objects when path segments do not exist
const obj2 = {};
setValue(obj2, 'config.database.credentials.port', 5432);
assert.strictEqual(obj2.config.database.credentials.port, 5432);
assert.strictEqual(typeof obj2.config, 'object');
assert.strictEqual(typeof obj2.config.database, 'object');

// 4. setPathValue creates intermediate arrays when next segment is an array index
const obj3 = {};
setPathValue(obj3, 'users[0].name', 'Bob');
assert.strictEqual(Array.isArray(obj3.users), true, 'users should be an array');
assert.strictEqual(obj3.users[0].name, 'Bob');

setPathValue(obj3, 'users[1]', 'Charlie');
assert.strictEqual(obj3.users[1], 'Charlie');

// 5. setPathValue mutates and returns the target object
const obj4 = { a: 1 };
const returnedObj = setPathValue(obj4, 'b.c', 2);
assert.strictEqual(returnedObj, obj4);
assert.strictEqual(obj4.a, 1);
assert.strictEqual(obj4.b.c, 2);

// 6. setPathValue handles escaped delimiters in property keys
const obj5 = {};
setPathValue(obj5, 'domain\\.com.enabled', true);
assert.strictEqual(obj5['domain.com'].enabled, true);

// 7. Prototype pollution protection
const obj6 = {};
setPathValue(obj6, '__proto__.polluted', true);
setPathValue(obj6, 'constructor.prototype.polluted', true);
setPathValue(obj6, 'prototype.polluted', true);
assert.strictEqual(Object.prototype.polluted, undefined, 'Object.prototype should not be polluted');
assert.strictEqual({}.polluted, undefined, 'Empty object should not have polluted property');

console.log('Contract tests passed successfully.');