bare-buffer 3.7.0: Buffer.prototype.writeInt16BE

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 Buffer.prototype.writeInt16BE in pkg:npm/bare-buffer@3.7.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/bare-buffer@3.7.0
Demonstrate these symbols/APIs:
  - Buffer.prototype.writeInt16BE
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: esm
  - 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:fe79bf551e2e7a88e2485d5ca52250516157e490cd9ea2f8703ac085cc0c9454","constraints":{"executionContext":"node"},"contract":["writeInt16BE writes positive 16-bit signed integer in big-endian byte order at specified offset","writeInt16BE writes negative 16-bit signed integer as two's complement in big-endian byte order","writeInt16BE returns the offset plus number of bytes written","writeInt16BE throws RangeError when offset is out of buffer bounds","writeInt16BE throws RangeError when offset is negative"],"goal":"verify Buffer.prototype.writeInt16BE in pkg:npm/bare-buffer@3.7.0","kind":"HOW","packages":["pkg:npm/bare-buffer@3.7.0"],"schemaVersion":1,"symbols":["Buffer.prototype.writeInt16BE"]},"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","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/bare-buffer@3.7.0"],"schemaVersion":1,"subject":"pkg:npm/bare-buffer@3.7.0","symbols":["Buffer.prototype.writeInt16BE"],"verifierAdapter":"node-typescript@1"}

import Module from 'node:module';

const mockBinding = {
  constants: {
    MAX_LENGTH: 2147483647,
    MAX_STRING_LENGTH: 1073741799
  },
  alloc(len) {
    return new ArrayBuffer(len);
  },
  allocUnsafe(len) {
    return new ArrayBuffer(len);
  }
};

const origCompile = Module.prototype._compile;
Module.prototype._compile = function (content, filename) {
  if (filename.includes('bare-buffer/binding.js')) {
    this.exports = mockBinding;
    this.loaded = true;
    return;
  }
  return origCompile.call(this, content, filename);
};

const { default: Buffer } = await import('bare-buffer');

export function writeInt16BE(buffer, value, offset = 0) {
  return buffer.writeInt16BE(value, offset);
}

export function createBuffer(size) {
  return Buffer.alloc(size);
}

export default Buffer;

{
  "name": "sample-bare-buffer-write-int16be",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-bare-buffer-write-int16be",
      "version": "1.0.0",
      "dependencies": {
        "bare-buffer": "3.7.0"
      }
    },
    "node_modules/bare-buffer": {
      "version": "3.7.0",
      "resolved": "https://registry.npmjs.org/bare-buffer/-/bare-buffer-3.7.0.tgz",
      "integrity": "sha512-/xRTbBuLis7sE3Izii0A0yOm+WqH1/gh12UVqkpIAOLZ4gWluyK0THbGB+UysKI8ZBjcZ+MaEs9Auxcyiz2yLA==",
      "license": "Apache-2.0",
      "engines": {
        "bare": ">=1.20.0"
      }
    }
  }
}

{
  "name": "sample-bare-buffer-write-int16be",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "bare-buffer": "3.7.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify Buffer.prototype.writeInt16BE in pkg:npm/bare-buffer@3.7.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/bare-buffer@3.7.0"
  ],
  "symbols": [
    "Buffer.prototype.writeInt16BE"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "esm",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import Buffer, { writeInt16BE, createBuffer } from '../index.js';

// 1. writeInt16BE writes positive 16-bit signed integer in big-endian byte order at specified offset
const buf1 = createBuffer(4);
const ret1 = writeInt16BE(buf1, 0x1234, 0);
assert.strictEqual(buf1[0], 0x12, 'First byte must be high byte 0x12');
assert.strictEqual(buf1[1], 0x34, 'Second byte must be low byte 0x34');
assert.strictEqual(buf1.readInt16BE(0), 0x1234, 'readInt16BE must return written 0x1234');

// 2. writeInt16BE writes negative 16-bit signed integer as two's complement in big-endian byte order
const buf2 = createBuffer(4);
const ret2 = writeInt16BE(buf2, -1234, 2);
assert.strictEqual(buf2[2], 0xfb, 'Third byte must be high byte 0xfb');
assert.strictEqual(buf2[3], 0x2e, 'Fourth byte must be low byte 0x2e');
assert.strictEqual(buf2.readInt16BE(2), -1234, 'readInt16BE must return written -1234');

// 3. writeInt16BE returns the offset plus number of bytes written
assert.strictEqual(ret1, 2, 'writeInt16BE at offset 0 must return offset + 2 = 2');
assert.strictEqual(ret2, 4, 'writeInt16BE at offset 2 must return offset + 2 = 4');

// 4. writeInt16BE throws RangeError when offset is out of buffer bounds
assert.throws(() => {
  const smallBuf = createBuffer(2);
  writeInt16BE(smallBuf, 0x1234, 2);
}, RangeError, 'writeInt16BE must throw RangeError when offset exceeds buffer capacity');

// 5. writeInt16BE throws RangeError when offset is negative
assert.throws(() => {
  const smallBuf = createBuffer(4);
  writeInt16BE(smallBuf, 0x1234, -1);
}, RangeError, 'writeInt16BE must throw RangeError when offset is negative');

console.log('Contract verification finished successfully.');