walk-up-path 3.0.1: walkUpPath

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 walkUpPath in pkg:npm/walk-up-path@3.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/walk-up-path@3.0.1
Demonstrate these symbols/APIs:
  - walkUpPath

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:sha256:7ae42f1934c951002d6c0851ef5812b849d61ab0754ae87fa670f9b46f144010","contract":["walkUpPath (exported as walkUp in walk-up-path v3) is a generator function returning an iterable iterator","walkUpPath walks up a multi-segment path from leaf to filesystem root without repeating root","walkUpPath resolves relative paths against the current working directory before walking up to root","walkUpPath on the root path yields only the root path once and terminates immediately","walkUpPath normalizes trailing separators and dot segments via path.resolve before yielding"],"goal":"verify walkUpPath in pkg:npm/walk-up-path@3.0.1","kind":"HOW","packages":["pkg:npm/walk-up-path@3.0.1"],"schemaVersion":1,"symbols":["walkUpPath"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/walk-up-path@3.0.1"],"schemaVersion":1,"subject":"pkg:npm/walk-up-path@3.0.1","symbols":["walkUpPath"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-walk-up-path",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-walk-up-path",
      "version": "1.0.0",
      "dependencies": {
        "walk-up-path": "3.0.1"
      }
    },
    "node_modules/walk-up-path": {
      "version": "3.0.1",
      "resolved": "https://registry.npmjs.org/walk-up-path/-/walk-up-path-3.0.1.tgz",
      "integrity": "sha512-9YlCL/ynK3CTlrSRrDxZvUauLzAswPCrsaCgilqFevUYpeEW0/3ScEjaa3kbW/T0ghhkEr7mv+fpjqn1Y1YuTA==",
      "license": "ISC"
    }
  }
}

{
  "name": "sample-walk-up-path",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "walk-up-path": "3.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify walkUpPath in pkg:npm/walk-up-path@3.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/walk-up-path@3.0.1"
  ],
  "symbols": [
    "walkUpPath"
  ]
}

import assert from 'node:assert/strict';
import path from 'node:path';
import { walkUp, walkUp as walkUpPath } from 'walk-up-path';

const root = path.parse(process.cwd()).root;

// 1. walkUpPath (exported as walkUp in walk-up-path v3) is a generator function returning an iterable iterator
{
  assert.equal(typeof walkUp, 'function');
  assert.strictEqual(walkUpPath, walkUp);
  const gen = walkUpPath(root);
  assert.equal(typeof gen.next, 'function');
  assert.equal(typeof gen[Symbol.iterator], 'function');
  assert.strictEqual(gen[Symbol.iterator](), gen);
}

// 2. walkUpPath walks up a multi-segment path from leaf to filesystem root without repeating root
{
  const deepPath = path.join(root, 'alpha', 'beta', 'gamma');
  const visited = Array.from(walkUpPath(deepPath));
  assert.deepEqual(visited, [
    path.join(root, 'alpha', 'beta', 'gamma'),
    path.join(root, 'alpha', 'beta'),
    path.join(root, 'alpha'),
    root,
  ]);
}

// 3. walkUpPath resolves relative paths against the current working directory before walking up to root
{
  const relPath = path.join('nested', 'leaf');
  const expectedStart = path.resolve(relPath);
  const visited = Array.from(walkUpPath(relPath));
  assert.equal(visited[0], expectedStart);
  assert.equal(visited[visited.length - 1], root);
  for (let i = 0; i < visited.length - 1; i++) {
    assert.equal(visited[i + 1], path.dirname(visited[i]));
    assert.notEqual(visited[i], visited[i + 1]);
  }
}

// 4. walkUpPath on the root path yields only the root path once and terminates immediately
{
  const visited = Array.from(walkUpPath(root));
  assert.deepEqual(visited, [root]);
}

// 5. walkUpPath normalizes trailing separators and dot segments via path.resolve before yielding
{
  const unnormalized = path.join(root, 'alpha', 'beta', '.', 'gamma') + path.sep;
  const visited = Array.from(walkUpPath(unnormalized));
  assert.deepEqual(visited, [
    path.join(root, 'alpha', 'beta', 'gamma'),
    path.join(root, 'alpha', 'beta'),
    path.join(root, 'alpha'),
    root,
  ]);
}