std-env 4.2.0: isWorkerd

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 std-env.isWorkerd in pkg:npm/std-env@4.2.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/std-env@4.2.0
Demonstrate these symbols/APIs:
  - std-env.isWorkerd

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:sha256:74e9363984d3a38c0d2fa0e57fad2e965f09b56a17743ee165a317bcb0bc9021","contract":["isWorkerd is exported as a boolean flag from std-env","isWorkerd evaluates to false in standard Node.js environment","isWorkerd is consistent with runtime property not being workerd in Node.js","isWorkerd is mutually exclusive with isNode in standard Node.js execution"],"goal":"verify std-env.isWorkerd in pkg:npm/std-env@4.2.0","kind":"HOW","packages":["pkg:npm/std-env@4.2.0"],"schemaVersion":1,"symbols":["std-env.isWorkerd"]},"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/std-env@4.2.0"],"schemaVersion":1,"subject":"pkg:npm/std-env@4.2.0","symbols":["std-env.isWorkerd"],"verifierAdapter":"node-typescript@1"}

{
  "name": "std-env-isworkerd-verification",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "std-env-isworkerd-verification",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "std-env": "4.2.0"
      }
    },
    "node_modules/std-env": {
      "version": "4.2.0",
      "resolved": "https://registry.npmjs.org/std-env/-/std-env-4.2.0.tgz",
      "integrity": "sha512-oCUKSupKTHX53EyjDtuZQ64pjLJ6yYCtpmEw0goYxtjG9KpbRe8KAsl2tBUGU9DyMcJ0RwJ8GqJAFzMXcXW1Rw==",
      "license": "MIT"
    }
  }
}

{
  "name": "std-env-isworkerd-verification",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "description": "Clean-room verification for std-env isWorkerd",
  "dependencies": {
    "std-env": "4.2.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify std-env.isWorkerd in pkg:npm/std-env@4.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/std-env@4.2.0"
  ],
  "symbols": [
    "std-env.isWorkerd"
  ]
}

import assert from "node:assert/strict";
import { isWorkerd, runtime, isNode } from "std-env";

// 1. isWorkerd is exported as a boolean flag from std-env
assert.strictEqual(typeof isWorkerd, "boolean");

// 2. isWorkerd evaluates to false in standard Node.js environment
assert.strictEqual(isWorkerd, false);

// 3. isWorkerd is consistent with runtime property not being workerd in Node.js
assert.notStrictEqual(runtime, "workerd");
assert.strictEqual(runtime, "node");

// 4. isWorkerd is mutually exclusive with isNode in standard Node.js execution
assert.strictEqual(isNode, true);
assert.notStrictEqual(isWorkerd, isNode);

console.log("Contract passed");