bare-stream 2.13.3: isWritable

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 bare-stream.isWritable in pkg:npm/bare-stream@2.13.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/bare-stream@2.13.3
Demonstrate these symbols/APIs:
  - bare-stream.isWritable
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:sha256:7e96936bbebe03516f39419d0c2f0fc850c0d3dfeae7b1033a4630758c7bb72e","constraints":{"executionContext":"node"},"contract":["isWritable returns true for an open Writable stream","isWritable returns false when a Writable stream is ending or finished","isWritable returns false when a Writable stream is destroyed","isWritable returns true for open Duplex, Transform, and PassThrough streams and false once ended","isWritable returns falsy for a purely Readable stream","isWritable returns falsy for non-stream objects without writable stream properties"],"goal":"verify bare-stream.isWritable in pkg:npm/bare-stream@2.13.3","kind":"HOW","packages":["pkg:npm/bare-stream@2.13.3"],"schemaVersion":1,"symbols":["bare-stream.isWritable"]},"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/bare-stream@2.13.3"],"schemaVersion":1,"subject":"pkg:npm/bare-stream@2.13.3","symbols":["bare-stream.isWritable"],"verifierAdapter":"node-typescript@1"}

const { Writable, Readable, Duplex, Transform, PassThrough, isWritable } = require('bare-stream');

/**
 * Checks whether a given stream is writable.
 * @param {object} stream
 * @returns {boolean}
 */
function checkWritable(stream) {
  return Boolean(isWritable(stream));
}

module.exports = {
  Writable,
  Readable,
  Duplex,
  Transform,
  PassThrough,
  isWritable,
  checkWritable
};

{
  "name": "sample-bare-stream-is-writable",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-bare-stream-is-writable",
      "version": "1.0.0",
      "dependencies": {
        "bare-stream": "2.13.3"
      }
    },
    "node_modules/b4a": {
      "version": "1.8.1",
      "resolved": "https://registry.npmjs.org/b4a/-/b4a-1.8.1.tgz",
      "integrity": "sha512-aiqre1Nr0B/6DgE2N5vwTc+2/oQZ4Wh1t4NznYY4E00y8LCt6NqdRv81so00oo27D8MVKTpUa/MwUUtBLXCoDw==",
      "license": "Apache-2.0",
      "peerDependencies": {
        "react-native-b4a": "*"
      },
      "peerDependenciesMeta": {
        "react-native-b4a": {
          "optional": true
        }
      }
    },
    "node_modules/bare-events": {
      "version": "2.9.2",
      "resolved": "https://registry.npmjs.org/bare-events/-/bare-events-2.9.2.tgz",
      "integrity": "sha512-AIPKioV7/Y/8KfZ3AAhjPJxLLbY49S64Ym5DakZlUg75qQiTgUq9hEJoEwa4eUezPUlXRy/i5NpsKvo9jgKmoA==",
      "license": "Apache-2.0",
      "peerDependencies": {
        "bare-abort-controller": "*"
      },
      "peerDependenciesMeta": {
        "bare-abort-controller": {
          "optional": true
        }
      }
    },
    "node_modules/bare-stream": {
      "version": "2.13.3",
      "resolved": "https://registry.npmjs.org/bare-stream/-/bare-stream-2.13.3.tgz",
      "integrity": "sha512-Kc+brLqvEqGkjyfiwJmImAOqLZL7OsoLKuavx+hJjgVV3nLTOjloJyPMFxjUPerGGHrNH0fLU06jjykMLWrERQ==",
      "license": "Apache-2.0",
      "dependencies": {
        "b4a": "^1.8.1",
        "streamx": "^2.25.0",
        "teex": "^1.0.1"
      },
      "peerDependencies": {
        "bare-abort-controller": "*",
        "bare-buffer": "*",
        "bare-events": "*"
      },
      "peerDependenciesMeta": {
        "bare-abort-controller": {
          "optional": true
        },
        "bare-buffer": {
          "optional": true
        },
        "bare-events": {
          "optional": true
        }
      }
    },
    "node_modules/events-universal": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/events-universal/-/events-universal-1.0.1.tgz",
      "integrity": "sha512-LUd5euvbMLpwOF8m6ivPCbhQeSiYVNb8Vs0fQ8QjXo0JTkEHpz8pxdQf0gStltaPpw0Cca8b39KxvK9cfKRiAw==",
      "license": "Apache-2.0",
      "dependencies": {
        "bare-events": "^2.7.0"
      }
    },
    "node_modules/fast-fifo": {
      "version": "1.3.2",
      "resolved": "https://registry.npmjs.org/fast-fifo/-/fast-fifo-1.3.2.tgz",
      "integrity": "sha512-/d9sfos4yxzpwkDkuN7k2SqFKtYNmCTzgfEpz82x34IM9/zc8KGxQoXg1liNC/izpRM/MBdt44Nmx41ZWqk+FQ==",
      "license": "MIT"
    },
    "node_modules/streamx": {
      "version": "2.28.1",
      "resolved": "https://registry.npmjs.org/streamx/-/streamx-2.28.1.tgz",
      "integrity": "sha512-zEzXb0s5Cds7tqMH6rhZ05lcJydCWiQPEwiNngVqzsxCc962vLY4Uw+mW7od8kDH258k2Uz/JrOkdIAAhSh9VA==",
      "license": "MIT",
      "dependencies": {
        "events-universal": "^1.0.0",
        "fast-fifo": "^1.3.2",
        "text-decoder": "^1.1.0"
      }
    },
    "node_modules/teex": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/teex/-/teex-1.0.1.tgz",
      "integrity": "sha512-eYE6iEI62Ni1H8oIa7KlDU6uQBtqr4Eajni3wX7rpfXD8ysFx8z0+dri+KWEPWpBsxXfxu58x/0jvTVT1ekOSg==",
      "license": "MIT",
      "dependencies": {
        "streamx": "^2.12.5"
      }
    },
    "node_modules/text-decoder": {
      "version": "1.2.7",
      "resolved": "https://registry.npmjs.org/text-decoder/-/text-decoder-1.2.7.tgz",
      "integrity": "sha512-vlLytXkeP4xvEq2otHeJfSQIRyWxo/oZGEbXrtEEF9Hnmrdly59sUbzZ/QgyWuLYHctCHxFF4tRQZNQ9k60ExQ==",
      "license": "Apache-2.0",
      "dependencies": {
        "b4a": "^1.6.4"
      }
    }
  }
}

{
  "name": "sample-bare-stream-is-writable",
  "version": "1.0.0",
  "private": true,
  "description": "verify bare-stream.isWritable in pkg:npm/bare-stream@2.13.3",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "bare-stream": "2.13.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify bare-stream.isWritable in pkg:npm/bare-stream@2.13.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/bare-stream@2.13.3"
  ],
  "symbols": [
    "bare-stream.isWritable"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

const assert = require('node:assert/strict');
const {
  Writable,
  Readable,
  Duplex,
  Transform,
  PassThrough,
  isWritable,
  checkWritable
} = require('../index.js');

// 1. isWritable returns true for an open Writable stream
const writableStream = new Writable({
  write(chunk, cb) {
    cb();
  }
});
assert.strictEqual(isWritable(writableStream), true, 'Open Writable stream should be writable');
assert.strictEqual(checkWritable(writableStream), true);

// 2. isWritable returns false when a Writable stream is ending or finished
writableStream.end();
assert.strictEqual(isWritable(writableStream), false, 'Ended Writable stream should not be writable');
assert.strictEqual(checkWritable(writableStream), false);

// 3. isWritable returns false when a Writable stream is destroyed
const destroyedStream = new Writable({
  write(chunk, cb) {
    cb();
  }
});
assert.strictEqual(isWritable(destroyedStream), true);
destroyedStream.destroy();
assert.strictEqual(isWritable(destroyedStream), false, 'Destroyed Writable stream should not be writable');
assert.strictEqual(checkWritable(destroyedStream), false);

// 4. isWritable returns true for open Duplex, Transform, and PassThrough streams
const duplexStream = new Duplex({
  read() {},
  write(chunk, cb) {
    cb();
  }
});
assert.strictEqual(isWritable(duplexStream), true, 'Open Duplex stream should be writable');
duplexStream.end();
assert.strictEqual(isWritable(duplexStream), false, 'Ended Duplex stream should not be writable');

const transformStream = new Transform({
  transform(chunk, cb) {
    cb(null, chunk);
  }
});
assert.strictEqual(isWritable(transformStream), true, 'Open Transform stream should be writable');
transformStream.end();
assert.strictEqual(isWritable(transformStream), false, 'Ended Transform stream should not be writable');

const passThroughStream = new PassThrough();
assert.strictEqual(isWritable(passThroughStream), true, 'Open PassThrough stream should be writable');
passThroughStream.end();
assert.strictEqual(isWritable(passThroughStream), false, 'Ended PassThrough stream should not be writable');

// 5. isWritable returns falsy for a purely Readable stream
const readableStream = new Readable({
  read() {
    this.push(null);
  }
});
assert.strictEqual(Boolean(isWritable(readableStream)), false, 'Readable stream should not be writable');
assert.strictEqual(checkWritable(readableStream), false);

// 6. isWritable returns falsy for non-stream objects
assert.strictEqual(Boolean(isWritable({})), false, 'Plain object should not be writable');
assert.strictEqual(checkWritable({}), false);

console.log('Contract assertions passed successfully.');