type-fest 0.13.1: Stringified

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 type-fest.Stringified in pkg:npm/type-fest@0.13.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/type-fest@0.13.1
Demonstrate these symbols/APIs:
  - type-fest.Stringified

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:a19085790acf8c5d571adcfc6f4537d3ed9690c48a29c895df9ec1c13713d38b","contract":["type-fest package.json defines package name as type-fest and version as 0.13.1 with types entry point","type-fest index declarations export Stringified symbol from source/stringified","source/stringified.d.ts defines Stringified generic mapped type transforming properties of ObjectType to string","Stringified mapped type contract changes object property value types to string","Stringified preserves object key structure while mapping heterogeneous types to strings"],"goal":"verify type-fest.Stringified in pkg:npm/type-fest@0.13.1","kind":"HOW","packages":["pkg:npm/type-fest@0.13.1"],"schemaVersion":1,"symbols":["type-fest.Stringified"]},"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/type-fest@0.13.1"],"schemaVersion":1,"subject":"pkg:npm/type-fest@0.13.1","symbols":["type-fest.Stringified"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-type-fest-stringified",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-type-fest-stringified",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "type-fest": "0.13.1"
      }
    },
    "node_modules/type-fest": {
      "version": "0.13.1",
      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.13.1.tgz",
      "integrity": "sha512-34R7HTnG0XIJcBSn5XhDd7nNFPRcXYRZrBB2O2jdKqYODldSzBAqzsWoZYYvduky73toYS/ESqxPvkDf/F0XMg==",
      "license": "(MIT OR CC0-1.0)",
      "engines": {
        "node": ">=10"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    }
  }
}

{
  "name": "sample-type-fest-stringified",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "license": "MIT-0",
  "dependencies": {
    "type-fest": "0.13.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify type-fest.Stringified in pkg:npm/type-fest@0.13.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/type-fest@0.13.1"
  ],
  "symbols": [
    "type-fest.Stringified"
  ]
}

import assert from 'node:assert/strict';
import fs from 'node:fs';
import path from 'node:path';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);

// Contract 1: type-fest package.json defines package name as type-fest and version as 0.13.1 with types entry point
{
  const pkgJson = require('type-fest/package.json');
  assert.equal(pkgJson.name, 'type-fest');
  assert.equal(pkgJson.version, '0.13.1');
  assert.equal(pkgJson.types, 'index.d.ts');
}

// Contract 2: type-fest index declarations export Stringified symbol from source/stringified
{
  const pkgDir = path.dirname(require.resolve('type-fest/package.json'));
  const indexDtsPath = path.join(pkgDir, 'index.d.ts');
  assert.ok(fs.existsSync(indexDtsPath), 'index.d.ts must exist');
  const indexDtsContent = fs.readFileSync(indexDtsPath, 'utf8');
  assert.ok(
    indexDtsContent.includes("export {Stringified} from './source/stringified';"),
    'Stringified must be exported from index.d.ts'
  );
}

// Contract 3: source/stringified.d.ts defines Stringified generic mapped type transforming properties of ObjectType to string
{
  const pkgDir = path.dirname(require.resolve('type-fest/package.json'));
  const stringifiedDtsPath = path.join(pkgDir, 'source', 'stringified.d.ts');
  assert.ok(fs.existsSync(stringifiedDtsPath), 'source/stringified.d.ts must exist');
  const stringifiedContent = fs.readFileSync(stringifiedDtsPath, 'utf8');
  assert.ok(
    stringifiedContent.includes('export type Stringified<ObjectType> = {[KeyType in keyof ObjectType]: string};'),
    'Stringified must be defined as {[KeyType in keyof ObjectType]: string}'
  );
}

// Contract 4: Stringified mapped type contract changes object property value types to string
{
  function stringifyValues(obj) {
    const result = {};
    for (const [key, value] of Object.entries(obj)) {
      result[key] = String(value);
    }
    return result;
  }

  const model = { model: 'Foo', speed: 101, active: true };
  const form = stringifyValues(model);
  assert.equal(typeof form.model, 'string');
  assert.equal(typeof form.speed, 'string');
  assert.equal(typeof form.active, 'string');
  assert.deepEqual(form, {
    model: 'Foo',
    speed: '101',
    active: 'true'
  });
}

// Contract 5: Stringified preserves object key structure while mapping heterogeneous types to strings
{
  function stringifyValues(obj) {
    const result = {};
    for (const [key, value] of Object.entries(obj)) {
      result[key] = String(value);
    }
    return result;
  }

  const complexRecord = { id: 42, count: 0, flag: false };
  const stringified = stringifyValues(complexRecord);
  assert.deepEqual(Object.keys(stringified), ['id', 'count', 'flag']);
  assert.equal(stringified.id, '42');
  assert.equal(stringified.count, '0');
  assert.equal(stringified.flag, 'false');
}

console.log('All pkg:npm/type-fest@0.13.1 type-fest.Stringified contracts passed successfully.');