pkce-challenge 5.0.1: verifyChallenge

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 pkce-challenge.verifyChallenge in pkg:npm/pkce-challenge@5.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/pkce-challenge@5.0.1
Demonstrate these symbols/APIs:
  - pkce-challenge.verifyChallenge

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:sha256:5c32fac853f14e0b4c8c8017882d9f98fbe6a38ce5cd362c6133319e74678a23","contract":["verifyChallenge returns true when the challenge matches the verifier","verifyChallenge returns false when the challenge does not match the verifier","verifyChallenge returns true for the RFC 7636 Appendix B test vector pair","verifyChallenge returns false when the verifier is altered","verifyChallenge returns false when the challenge is altered","verifyChallenge resolves to a boolean promise"],"goal":"verify pkce-challenge.verifyChallenge in pkg:npm/pkce-challenge@5.0.1","kind":"HOW","packages":["pkg:npm/pkce-challenge@5.0.1"],"schemaVersion":1,"symbols":["pkce-challenge.verifyChallenge"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/pkce-challenge@5.0.1"],"schemaVersion":1,"subject":"pkg:npm/pkce-challenge@5.0.1","symbols":["pkce-challenge.verifyChallenge"],"verifierAdapter":"node-typescript@1"}

import { verifyChallenge } from "pkce-challenge";

/**
 * Verifies that a given PKCE code verifier matches the expected code challenge.
 *
 * @param {string} codeVerifier - The PKCE code verifier string.
 * @param {string} expectedChallenge - The expected base64url-encoded SHA-256 challenge.
 * @returns {Promise<boolean>} True if the challenge matches the verifier, false otherwise.
 */
export async function isChallengeValid(codeVerifier, expectedChallenge) {
  return await verifyChallenge(codeVerifier, expectedChallenge);
}

export { verifyChallenge };
export default verifyChallenge;

{
  "name": "sample-pkce-challenge-verify-challenge",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pkce-challenge-verify-challenge",
      "version": "1.0.0",
      "dependencies": {
        "pkce-challenge": "5.0.1"
      }
    },
    "node_modules/pkce-challenge": {
      "version": "5.0.1",
      "resolved": "https://registry.npmjs.org/pkce-challenge/-/pkce-challenge-5.0.1.tgz",
      "integrity": "sha512-wQ0b/W4Fr01qtpHlqSqspcj3EhBvimsdh0KlHhH8HRZnMsEa0ea2fTULOXOS9ccQr3om+GcGRk4e+isrZWV8qQ==",
      "license": "MIT",
      "engines": {
        "node": ">=16.20.0"
      }
    }
  }
}

{
  "name": "sample-pkce-challenge-verify-challenge",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "description": "Clean-room code sample for pkce-challenge.verifyChallenge in pkce-challenge@5.0.1",
  "main": "index.js",
  "dependencies": {
    "pkce-challenge": "5.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkce-challenge.verifyChallenge in pkg:npm/pkce-challenge@5.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pkce-challenge@5.0.1"
  ],
  "symbols": [
    "pkce-challenge.verifyChallenge"
  ]
}

import assert from "node:assert/strict";
import { createHash } from "node:crypto";
import { verifyChallenge } from "pkce-challenge";

async function run() {
  // Reference test vector from RFC 7636 Appendix B
  const rfcVerifier = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk";
  const rfcExpectedChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM";

  // Arbitrary custom verifier and its expected SHA-256 base64url challenge
  const customVerifier = "sample_verifier_string_for_pkce_contract_test_12345";
  const customChallenge = createHash("sha256")
    .update(customVerifier)
    .digest("base64url");

  // 1. verifyChallenge returns true when the challenge matches the verifier
  const customMatches = await verifyChallenge(customVerifier, customChallenge);
  assert.equal(customMatches, true);

  // 2. verifyChallenge returns false when the challenge does not match the verifier
  const customMismatches = await verifyChallenge(customVerifier, "mismatched_challenge_value_1234567890abcdef");
  assert.equal(customMismatches, false);

  // 3. verifyChallenge returns true for the RFC 7636 Appendix B test vector pair
  const rfcMatches = await verifyChallenge(rfcVerifier, rfcExpectedChallenge);
  assert.equal(rfcMatches, true);

  // 4. verifyChallenge returns false when the verifier is altered
  const alteredVerifier = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXz";
  const alteredVerifierResult = await verifyChallenge(alteredVerifier, rfcExpectedChallenge);
  assert.equal(alteredVerifierResult, false);

  // 5. verifyChallenge returns false when the challenge is altered
  const alteredChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cz";
  const alteredChallengeResult = await verifyChallenge(rfcVerifier, alteredChallenge);
  assert.equal(alteredChallengeResult, false);

  // 6. verifyChallenge resolves to a boolean promise
  const resultPromise = verifyChallenge(customVerifier, customChallenge);
  assert.ok(resultPromise instanceof Promise);
  const boolResult = await resultPromise;
  assert.equal(typeof boolResult, "boolean");

  console.log("All pkce-challenge.verifyChallenge contract checks passed.");
}

await run();