readable-stream 2.3.8: Readable

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 readable-stream.Readable in pkg:npm/readable-stream@2.3.8
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/readable-stream@2.3.8
Demonstrate these symbols/APIs:
  - readable-stream.Readable

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:sha256:76315e97f860a9e864a1e58286611975ae900a7dc7d863ce4c4f68975e618b84","contract":["Readable stream emits queued chunks in flowing mode via data and end events","Readable stream in paused mode supports synchronous read via readable events","Readable stream with objectMode pushes and reads JavaScript objects"],"goal":"verify readable-stream.Readable in pkg:npm/readable-stream@2.3.8","kind":"HOW","packages":["pkg:npm/readable-stream@2.3.8"],"schemaVersion":1,"symbols":["readable-stream.Readable"]},"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@2.3.8"],"schemaVersion":1,"subject":"pkg:npm/readable-stream@2.3.8","symbols":["readable-stream.Readable"],"verifierAdapter":"node-typescript@1"}

const { Readable } = require('readable-stream');

/**
 * Creates a Readable stream that emits items from an array.
 *
 * @param {Array<string|Buffer>} items
 * @param {object} [options]
 * @returns {Readable}
 */
function createReadableStream(items = [], options = {}) {
  let index = 0;
  return new Readable({
    ...options,
    read() {
      if (index < items.length) {
        this.push(items[index++]);
      } else {
        this.push(null);
      }
    },
  });
}

/**
 * Creates an object-mode Readable stream that emits object items.
 *
 * @param {Array<any>} items
 * @returns {Readable}
 */
function createObjectStream(items = []) {
  return createReadableStream(items, { objectMode: true });
}

module.exports = {
  Readable,
  createReadableStream,
  createObjectStream,
};

{
  "name": "sample-readable-stream-readable",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-readable-stream-readable",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "readable-stream": "2.3.8"
      }
    },
    "node_modules/core-util-is": {
      "version": "1.0.3",
      "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.3.tgz",
      "integrity": "sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ==",
      "license": "MIT"
    },
    "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/isarray": {
      "version": "1.0.0",
      "resolved": "https://registry.npmjs.org/isarray/-/isarray-1.0.0.tgz",
      "integrity": "sha512-VLghIWNM6ELQzo7zwmcg0NmTVyWKYjvIeM83yjp0wRDTmUnrM678fQbcKBo6n2CJEF0szoG//ytg+TKla89ALQ==",
      "license": "MIT"
    },
    "node_modules/process-nextick-args": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-2.0.1.tgz",
      "integrity": "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag==",
      "license": "MIT"
    },
    "node_modules/readable-stream": {
      "version": "2.3.8",
      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.3.8.tgz",
      "integrity": "sha512-8p0AUk4XODgIewSi0l8Epjs+EVnWiK7NoDIEGU0HhE7+ZyY8D1IMY7odu5lRrFXGg71L15KG8QrPmum45RTtdA==",
      "license": "MIT",
      "dependencies": {
        "core-util-is": "~1.0.0",
        "inherits": "~2.0.3",
        "isarray": "~1.0.0",
        "process-nextick-args": "~2.0.0",
        "safe-buffer": "~5.1.1",
        "string_decoder": "~1.1.1",
        "util-deprecate": "~1.0.1"
      }
    },
    "node_modules/safe-buffer": {
      "version": "5.1.2",
      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.1.2.tgz",
      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==",
      "license": "MIT"
    },
    "node_modules/string_decoder": {
      "version": "1.1.1",
      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.1.1.tgz",
      "integrity": "sha512-n/ShnvDi6FHbbVfviro+WojiFzv+s8MPMHBczVePfUpDJLwoLT0ht1l4YwBCbi8pJAveEEdnkHyPyTP/mzRfwg==",
      "license": "MIT",
      "dependencies": {
        "safe-buffer": "~5.1.0"
      }
    },
    "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-readable",
  "version": "1.0.0",
  "description": "Verify readable-stream Readable stream implementation and data emission",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "readable-stream": "2.3.8"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify readable-stream.Readable in pkg:npm/readable-stream@2.3.8",
  "kind": "HOW",
  "packages": [
    "pkg:npm/readable-stream@2.3.8"
  ],
  "symbols": [
    "readable-stream.Readable"
  ]
}

const assert = require('node:assert');
const { Readable, createReadableStream, createObjectStream } = require('../index.js');

async function main() {
  // 1. Readable stream emits queued chunks in flowing mode via data and end events
  {
    const stream = createReadableStream(['chunk1', 'chunk2', 'chunk3']);
    const received = [];

    stream.on('data', (chunk) => {
      received.push(chunk.toString());
    });

    await new Promise((resolve, reject) => {
      stream.on('end', resolve);
      stream.on('error', reject);
    });

    assert.deepStrictEqual(received, ['chunk1', 'chunk2', 'chunk3']);
  }

  // 2. Readable stream in paused mode supports synchronous read via readable events
  {
    const stream = createReadableStream(['alpha', 'beta']);
    const chunks = [];

    await new Promise((resolve, reject) => {
      stream.on('readable', () => {
        let chunk;
        while ((chunk = stream.read()) !== null) {
          chunks.push(chunk.toString());
        }
      });
      stream.on('end', resolve);
      stream.on('error', reject);
    });

    assert.strictEqual(chunks.join(''), 'alphabeta');
  }

  // 3. Readable stream with objectMode pushes and reads JavaScript objects
  {
    const objects = [{ id: 1, name: 'first' }, { id: 2, name: 'second' }];
    const stream = createObjectStream(objects);
    const collected = [];

    stream.on('data', (item) => {
      collected.push(item);
    });

    await new Promise((resolve, reject) => {
      stream.on('end', resolve);
      stream.on('error', reject);
    });

    assert.deepStrictEqual(collected, objects);
  }

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

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