is-cidr 5.1.1: isCidr, v4, v6

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 pkg:npm/is-cidr@5.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/is-cidr@5.1.1

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:d2cc2f03d42ff958ee29494820e94965a83c744e1e93fc6646b84506c33e6a9a","contract":["isCidr(str) returns 4 for valid IPv4 CIDR strings, 6 for valid IPv6 CIDR strings, and 0 for non-CIDR or plain IP strings","v4(str) and isCidr.v4(str) return true only for valid IPv4 CIDR notation and false for IPv6 CIDR or invalid inputs","v6(str) and isCidr.v6(str) return true only for valid IPv6 CIDR notation and false for IPv4 CIDR or invalid inputs"],"goal":"verify pkg:npm/is-cidr@5.1.1","kind":"HOW","packages":["pkg:npm/is-cidr@5.1.1"],"schemaVersion":1,"symbols":["isCidr","v4","v6"]},"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/is-cidr@5.1.1"],"schemaVersion":1,"subject":"pkg:npm/is-cidr@5.1.1","symbols":["isCidr","v4","v6"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample",
      "version": "1.0.0",
      "dependencies": {
        "is-cidr": "5.1.1"
      }
    },
    "node_modules/cidr-regex": {
      "version": "4.1.3",
      "resolved": "https://registry.npmjs.org/cidr-regex/-/cidr-regex-4.1.3.tgz",
      "integrity": "sha512-86M1y3ZeQvpZkZejQCcS+IaSWjlDUC+ORP0peScQ4uEUFCZ8bEQVz7NlJHqysoUb6w3zCjx4Mq/8/2RHhMwHYw==",
      "license": "BSD-2-Clause",
      "dependencies": {
        "ip-regex": "^5.0.0"
      },
      "engines": {
        "node": ">=14"
      }
    },
    "node_modules/ip-regex": {
      "version": "5.0.0",
      "resolved": "https://registry.npmjs.org/ip-regex/-/ip-regex-5.0.0.tgz",
      "integrity": "sha512-fOCG6lhoKKakwv+C6KdsOnGvgXnmgfmp0myi3bcNwj3qfwPAxRKWEuFhvEFF7ceYIz6+1jRZ+yguLFAmUNPEfw==",
      "license": "MIT",
      "engines": {
        "node": "^12.20.0 || ^14.13.1 || >=16.0.0"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
    "node_modules/is-cidr": {
      "version": "5.1.1",
      "resolved": "https://registry.npmjs.org/is-cidr/-/is-cidr-5.1.1.tgz",
      "integrity": "sha512-AwzRMjtJNTPOgm7xuYZ71715z99t+4yRnSnSzgK5err5+heYi4zMuvmpUadaJ28+KCXCQo8CjUrKQZRWSPmqTQ==",
      "license": "BSD-2-Clause",
      "dependencies": {
        "cidr-regex": "^4.1.1"
      },
      "engines": {
        "node": ">=14"
      }
    }
  }
}

{
  "name": "sample",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "is-cidr": "5.1.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/is-cidr@5.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/is-cidr@5.1.1"
  ]
}

import assert from "node:assert/strict";
import isCidr, { v4, v6 } from "is-cidr";

assert.equal(isCidr("192.168.0.0/24"), 4);
assert.equal(isCidr("2001:db8::/32"), 6);
assert.equal(isCidr("192.168.0.1"), 0);
assert.equal(isCidr("not-a-cidr"), 0);

assert.equal(v4("10.0.0.0/8"), true);
assert.equal(v4("2001:db8::/32"), false);
assert.equal(isCidr.v4("172.16.0.0/12"), true);
assert.equal(isCidr.v4("fe80::/10"), false);

assert.equal(v6("2001:db8::/32"), true);
assert.equal(v6("10.0.0.0/8"), false);
assert.equal(isCidr.v6("fe80::/10"), true);
assert.equal(isCidr.v6("192.168.1.0/24"), false);