clone-response 1.0.3: clone response stream with metadata and body

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: clone response stream with metadata and body
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/clone-response@1.0.3
Demonstrate these symbols/APIs:
  - cloneResponse

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:sha256:2c7c87ea6ac0ed22fb2a90b77759f784f24d36e4991fe3513d998ad4206a9a77","contract":["cloneResponse clones a readable stream while copying response metadata including statusCode, statusMessage, and headers","cloneResponse throws TypeError when input is missing or lacks a pipe method","cloneResponse preserves custom properties and pipes multi-chunk payload to the clone"],"goal":"clone response stream with metadata and body","kind":"HOW","packages":["pkg:npm/clone-response@1.0.3"],"schemaVersion":1,"symbols":["cloneResponse"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/clone-response@1.0.3"],"schemaVersion":1,"subject":"pkg:npm/clone-response@1.0.3","symbols":["cloneResponse"],"verifierAdapter":"node-typescript@1"}

{
  "name": "clone-response-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "clone-response-sample",
      "version": "1.0.0",
      "dependencies": {
        "clone-response": "1.0.3"
      }
    },
    "node_modules/clone-response": {
      "version": "1.0.3",
      "resolved": "https://registry.npmjs.org/clone-response/-/clone-response-1.0.3.tgz",
      "integrity": "sha512-ROoL94jJH2dUVML2Y/5PEDNaSHgeOdSDicUyS7izcF63G6sTc/FTjLub4b8Il9S8S0beOfYt0TaA5qvFK+w0wA==",
      "license": "MIT",
      "dependencies": {
        "mimic-response": "^1.0.0"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
    "node_modules/mimic-response": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/mimic-response/-/mimic-response-1.0.1.tgz",
      "integrity": "sha512-j5EctnkH7amfV/q5Hgmoal1g2QHFJRraOtmx0JpIqkxhBhI/lJSl1nMpQ45hVarwNETOoWEimndZ4QK0RHxuxQ==",
      "license": "MIT",
      "engines": {
        "node": ">=4"
      }
    }
  }
}

{
  "name": "clone-response-sample",
  "version": "1.0.0",
  "dependencies": {
    "clone-response": "1.0.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "clone response stream with metadata and body",
  "kind": "HOW",
  "packages": [
    "pkg:npm/clone-response@1.0.3"
  ],
  "symbols": [
    "cloneResponse"
  ]
}

'use strict';

const cloneResponse = require('clone-response');

/**
 * Creates a duplicate of an HTTP response stream with copied metadata and stream body.
 *
 * @param {import('stream').Readable} response - The original response stream to clone.
 * @returns {import('stream').PassThrough} The cloned response stream.
 */
function createResponseClone(response) {
  return cloneResponse(response);
}

/**
 * Helper to collect all data chunks from a readable stream as a utf-8 string.
 *
 * @param {import('stream').Readable} stream - The stream to read.
 * @returns {Promise<string>} The concatenated text content.
 */
function readStreamToString(stream) {
  return new Promise((resolve, reject) => {
    let data = '';
    stream.setEncoding('utf8');
    stream.on('data', chunk => {
      data += chunk;
    });
    stream.on('end', () => {
      resolve(data);
    });
    stream.on('error', err => {
      reject(err);
    });
  });
}

module.exports = {
  cloneResponse,
  createResponseClone,
  readStreamToString,
};

'use strict';

const assert = require('node:assert/strict');
const { PassThrough } = require('node:stream');
const {
  cloneResponse,
  createResponseClone,
  readStreamToString,
} = require('../src/index.js');

async function main() {
  // Contract 1: cloneResponse clones a readable stream while copying response metadata including statusCode, statusMessage, and headers
  {
    const original = new PassThrough();
    original.statusCode = 200;
    original.statusMessage = 'OK';
    original.headers = {
      'content-type': 'application/json',
      'cache-control': 'max-age=3600',
    };
    original.rawHeaders = [
      'Content-Type',
      'application/json',
      'Cache-Control',
      'max-age=3600',
    ];

    const clone = createResponseClone(original);

    assert.strictEqual(clone.statusCode, 200, 'Cloned stream should preserve statusCode');
    assert.strictEqual(clone.statusMessage, 'OK', 'Cloned stream should preserve statusMessage');
    assert.deepStrictEqual(
      clone.headers,
      {
        'content-type': 'application/json',
        'cache-control': 'max-age=3600',
      },
      'Cloned stream should preserve headers object'
    );
    assert.deepStrictEqual(
      clone.rawHeaders,
      [
        'Content-Type',
        'application/json',
        'Cache-Control',
        'max-age=3600',
      ],
      'Cloned stream should preserve rawHeaders array'
    );

    const payload = JSON.stringify({ message: 'cloned stream response data' });
    const readPromise = readStreamToString(clone);

    original.write(payload);
    original.end();

    const output = await readPromise;
    assert.strictEqual(output, payload, 'Cloned stream body should match original streamed data');
  }

  // Contract 2: cloneResponse throws TypeError when input is missing or lacks a pipe method
  {
    const missingOrNonPipeInputs = [null, undefined, 42, 'not-a-stream', {}];

    for (const invalid of missingOrNonPipeInputs) {
      assert.throws(
        () => cloneResponse(invalid),
        (err) => {
          assert.ok(err instanceof TypeError, 'Should throw a TypeError');
          assert.strictEqual(
            err.message,
            'Parameter `response` must be a response stream.',
            'Error message must match expected stream requirement'
          );
          return true;
        }
      );
    }

    assert.throws(
      () => cloneResponse({ pipe: 'not-a-function' }),
      (err) => {
        assert.ok(err instanceof TypeError, 'Should throw a TypeError when pipe is not callable');
        assert.strictEqual(err.message, 'response.pipe is not a function');
        return true;
      }
    );
  }

  // Contract 3: cloneResponse preserves custom properties and pipes multi-chunk payload to the clone
  {
    const original = new PassThrough();
    original.customTraceId = 'req-12345';
    original.statusCode = 206;

    const clone = createResponseClone(original);
    assert.strictEqual(clone.customTraceId, 'req-12345', 'Cloned stream should copy custom response properties');
    assert.strictEqual(clone.statusCode, 206, 'Cloned stream should preserve statusCode 206');

    const readPromise = readStreamToString(clone);

    original.write('chunk1-');
    original.write('chunk2-');
    original.end('chunk3');

    const output = await readPromise;
    assert.strictEqual(output, 'chunk1-chunk2-chunk3', 'Cloned stream should stream all chunks sequentially');
  }

  console.log('All pkg:npm/clone-response@1.0.3 contracts passed successfully.');
}

main().catch((err) => {
  console.error('Contract test failed:', err);
  process.exit(1);
});