cidr-regex 4.1.3: cidrRegex.v4, v4

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 cidrRegex.v4 in pkg:npm/cidr-regex@4.1.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/cidr-regex@4.1.3
Demonstrate these symbols/APIs:
  - cidrRegex.v4

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:df6b148a2dc69f5b58ec4d0a8d6ebc65c95cf518783b8e2ab462360986df59f1","contract":["cidrRegex.v4({ exact: true }) matches valid IPv4 CIDR strings (prefix 0-32) and rejects bare IPs, invalid prefixes, IPv6 CIDRs, or surrounding text","cidrRegex.v4() defaults to a global RegExp for extracting IPv4 CIDR blocks from text while ignoring IPv6 CIDRs","cidrRegex.v4 and the named export v4 are the same function"],"goal":"verify cidrRegex.v4 in pkg:npm/cidr-regex@4.1.3","kind":"HOW","packages":["pkg:npm/cidr-regex@4.1.3"],"schemaVersion":1,"symbols":["cidrRegex.v4","v4"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/cidr-regex@4.1.3"],"schemaVersion":1,"subject":"pkg:npm/cidr-regex@4.1.3","symbols":["cidrRegex.v4","v4"],"verifierAdapter":"node-typescript@1"}

import cidrRegex, { v4 } from "cidr-regex";

export function isExactIpv4Cidr(input) {
  return cidrRegex.v4({ exact: true }).test(input);
}

export function extractIpv4Cidrs(text) {
  return text.match(cidrRegex.v4()) ?? [];
}

export { v4 };

{
  "name": "cidr-regex-v4-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "cidr-regex-v4-sample",
      "version": "1.0.0",
      "dependencies": {
        "cidr-regex": "4.1.3"
      }
    },
    "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"
      }
    }
  }
}

{
  "name": "cidr-regex-v4-sample",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "cidr-regex": "4.1.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify cidrRegex.v4 in pkg:npm/cidr-regex@4.1.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/cidr-regex@4.1.3"
  ],
  "symbols": [
    "cidrRegex.v4"
  ]
}

import assert from "node:assert/strict";
import cidrRegex, { v4 } from "cidr-regex";
import { isExactIpv4Cidr, extractIpv4Cidrs } from "../index.mjs";

// cidrRegex.v4 and named export v4 reference the same function
assert.equal(cidrRegex.v4, v4);

// Exact matching accepts valid IPv4 CIDRs with prefix length 0..32
assert.equal(isExactIpv4Cidr("0.0.0.0/0"), true);
assert.equal(isExactIpv4Cidr("192.168.1.0/24"), true);
assert.equal(isExactIpv4Cidr("10.0.0.1/32"), true);

// Exact matching rejects invalid prefix lengths, bare IPv4s, IPv6 CIDRs, and surrounding text
assert.equal(isExactIpv4Cidr("192.168.1.0/33"), false);
assert.equal(isExactIpv4Cidr("192.168.1.1"), false);
assert.equal(isExactIpv4Cidr("2001:db8::/32"), false);
assert.equal(isExactIpv4Cidr("range 192.168.1.0/24 end"), false);

// Default non-exact call returns a global RegExp that extracts only IPv4 CIDRs from text
const regexDefault = cidrRegex.v4();
assert.equal(regexDefault.global, true);

const sampleText = "Subnets: 10.0.0.0/8, 2001:db8::/32, and 172.16.0.0/12.";
assert.deepEqual(extractIpv4Cidrs(sampleText), ["10.0.0.0/8", "172.16.0.0/12"]);
assert.deepEqual(extractIpv4Cidrs("no ipv4 cidr here"), []);