type-fest 0.13.1: ValueOf

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.ValueOf 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.ValueOf

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:sha256:29b21561c77d83b69ef5a4d5afe530f1541d072bcf34612f9154230808cdc55b","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 ValueOf symbol from source/value-of","ValueOf type definition accepts generic ObjectType and ValueType parameters","ValueOf constrains ValueType to extend keyof ObjectType with default of keyof ObjectType","ValueOf indexes ObjectType by ValueType to return the union of property value types"],"goal":"verify type-fest.ValueOf in pkg:npm/type-fest@0.13.1","kind":"HOW","packages":["pkg:npm/type-fest@0.13.1"],"schemaVersion":1,"symbols":["type-fest.ValueOf"]},"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.ValueOf"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-type-fest-value-of",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-type-fest-value-of",
      "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-value-of",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "license": "MIT-0",
  "dependencies": {
    "type-fest": "0.13.1"
  }
}

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

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 ValueOf symbol from source/value-of
{
  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 {ValueOf} from './source/value-of';"),
    'ValueOf must be exported from index.d.ts'
  );
}

// Contract 3: ValueOf type definition accepts generic ObjectType and ValueType parameters
{
  const pkgDir = path.dirname(require.resolve('type-fest/package.json'));
  const valueOfDtsPath = path.join(pkgDir, 'source', 'value-of.d.ts');
  assert.ok(fs.existsSync(valueOfDtsPath), 'source/value-of.d.ts must exist');
  const valueOfContent = fs.readFileSync(valueOfDtsPath, 'utf8');
  assert.ok(
    valueOfContent.includes('export type ValueOf<ObjectType, ValueType'),
    'ValueOf must accept ObjectType and ValueType type parameters'
  );
}

// Contract 4: ValueOf constrains ValueType to extend keyof ObjectType with default of keyof ObjectType
{
  const pkgDir = path.dirname(require.resolve('type-fest/package.json'));
  const valueOfDtsPath = path.join(pkgDir, 'source', 'value-of.d.ts');
  const valueOfContent = fs.readFileSync(valueOfDtsPath, 'utf8');
  assert.ok(
    valueOfContent.includes('ValueType extends keyof ObjectType = keyof ObjectType>'),
    'ValueOf must constrain ValueType to extend keyof ObjectType with default keyof ObjectType'
  );
}

// Contract 5: ValueOf indexes ObjectType by ValueType to return the union of property value types
{
  const pkgDir = path.dirname(require.resolve('type-fest/package.json'));
  const valueOfDtsPath = path.join(pkgDir, 'source', 'value-of.d.ts');
  const valueOfContent = fs.readFileSync(valueOfDtsPath, 'utf8');
  assert.ok(
    valueOfContent.includes('= ObjectType[ValueType];'),
    'ValueOf must index ObjectType by ValueType'
  );
}

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