readable-stream 3.6.2

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/readable-stream@3.6.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/readable-stream@3.6.2

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:c6166ab5f4597b4ea61a1b03bcc5dda50a8982febf7567dc672575f9b87cce97","contract":["Readable stream emits chunks and ends","Transform stream transforms data chunks","pipeline chains source through transform to sink and collects result"],"goal":"verify pkg:npm/readable-stream@3.6.2","kind":"HOW","packages":["pkg:npm/readable-stream@3.6.2"],"schemaVersion":1},"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/readable-stream@3.6.2"],"schemaVersion":1,"subject":"pkg:npm/readable-stream@3.6.2","verifierAdapter":"node-typescript@1"}

const { Readable, Writable, Transform, pipeline } = require('readable-stream');

/**
 * Creates a readable stream from an array of strings or Buffers.
 *
 * @param {Array<string|Buffer>} items
 * @returns {Readable}
 */
function createArrayStream(items) {
  let index = 0;
  return new Readable({
    objectMode: false,
    read() {
      if (index < items.length) {
        this.push(items[index++]);
      } else {
        this.push(null);
      }
    },
  });
}

/**
 * Creates an uppercase transform stream.
 *
 * @returns {Transform}
 */
function createUppercaseTransform() {
  return new Transform({
    transform(chunk, encoding, callback) {
      callback(null, chunk.toString().toUpperCase());
    },
  });
}

/**
 * Collects a readable stream's contents into a single string.
 *
 * @param {Readable} stream
 * @returns {Promise<string>}
 */
function collectStream(stream) {
  return new Promise((resolve, reject) => {
    let result = '';
    const sink = new Writable({
      write(chunk, encoding, callback) {
        result += chunk.toString();
        callback();
      },
    });

    pipeline(stream, sink, (err) => {
      if (err) {
        reject(err);
      } else {
        resolve(result);
      }
    });
  });
}

module.exports = {
  Readable,
  Writable,
  Transform,
  pipeline,
  createArrayStream,
  createUppercaseTransform,
  collectStream,
};

{
  "name": "sample-readable-stream",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-readable-stream",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "readable-stream": "3.6.2"
      }
    },
    "node_modules/inherits": {
      "version": "2.0.4",
      "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==",
      "license": "ISC"
    },
    "node_modules/readable-stream": {
      "version": "3.6.2",
      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.6.2.tgz",
      "integrity": "sha512-9u/sniCrY3D5WdsERHzHE4G2YCXqoG5FTHUiCC4SIbr6XcLZBY05ya9EKjYek9O5xOAwjGq+1JdGBAS7Q9ScoA==",
      "license": "MIT",
      "dependencies": {
        "inherits": "^2.0.3",
        "string_decoder": "^1.1.1",
        "util-deprecate": "^1.0.1"
      },
      "engines": {
        "node": ">= 6"
      }
    },
    "node_modules/safe-buffer": {
      "version": "5.2.1",
      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
      "integrity": "sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==",
      "funding": [
        {
          "type": "github",
          "url": "https://github.com/sponsors/feross"
        },
        {
          "type": "patreon",
          "url": "https://www.patreon.com/feross"
        },
        {
          "type": "consulting",
          "url": "https://feross.org/support"
        }
      ],
      "license": "MIT"
    },
    "node_modules/string_decoder": {
      "version": "1.3.0",
      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.3.0.tgz",
      "integrity": "sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA==",
      "license": "MIT",
      "dependencies": {
        "safe-buffer": "~5.2.0"
      }
    },
    "node_modules/util-deprecate": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz",
      "integrity": "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-readable-stream",
  "version": "1.0.0",
  "description": "Verify readable-stream stream creation, transformation, and pipeline",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "readable-stream": "3.6.2"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/readable-stream@3.6.2",
  "kind": "HOW",
  "packages": [
    "pkg:npm/readable-stream@3.6.2"
  ]
}

const assert = require('node:assert');
const {
  Readable,
  Writable,
  Transform,
  pipeline,
  createArrayStream,
  createUppercaseTransform,
  collectStream,
} = require('../index.js');

async function main() {
  // 1. Readable stream emits chunks and ends
  {
    const source = createArrayStream(['hello', ' ', 'world']);
    const chunks = [];
    source.on('data', (chunk) => chunks.push(chunk.toString()));
    await new Promise((resolve) => source.on('end', resolve));
    assert.strictEqual(chunks.join(''), 'hello world');
  }

  // 2. Transform stream transforms data chunks
  {
    const transform = createUppercaseTransform();
    const source = createArrayStream(['foo', 'bar']);
    const output = [];
    transform.on('data', (chunk) => output.push(chunk.toString()));

    pipeline(source, transform, (err) => {
      assert.ifError(err);
    });

    await new Promise((resolve) => transform.on('end', resolve));
    assert.strictEqual(output.join(''), 'FOOBAR');
  }

  // 3. pipeline chains source through transform to sink and collects result
  {
    const source = createArrayStream(['clean', '-', 'room', ' ', 'streams']);
    const transform = createUppercaseTransform();
    const transformedStream = source.pipe(transform);
    const result = await collectStream(transformedStream);
    assert.strictEqual(result, 'CLEAN-ROOM STREAMS');
  }

  console.log('Contract test passed successfully.');
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});