CodeSampleX

Sample

bare-buffer 3.7.0: Buffer.prototype.readUInt16BE

Verified sample for npm bare-buffer 3.7.0: Buffer.prototype.readUInt16BE. The contract ran on node 22 · linux alpine/x64 · docker and passed.

sha256:e45c56807c381e125b5d9a1ff9d89a7a23fe831b74378ad3af0941711bb9c510

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux 24 · ubuntu · glibc 2.39 x64 npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…
2026-08-27

Case

HOW
Goal
verify Buffer.prototype.readUInt16BE in pkg:npm/bare-buffer@3.7.0
Packages
Symbols
  • Buffer.prototype.readUInt16BE
Created
2026-08-27T05:37:40Z

Contract

  1. Buffer.prototype.readUInt16BE is a function aliasing Buffer.prototype.readUint16BE
  2. buf.readUInt16BE() defaults to offset 0 and returns big-endian 16-bit unsigned integer
  3. buf.readUInt16BE(offset) reads 16-bit big-endian unsigned integer at specified byte offset
  4. buf.readUInt16BE throws RangeError when offset is out of bounds, negative, or non-integer
  5. buf.readUInt16BE throws TypeError when offset is not a number

Files

  • PROMPT.md
  • csx.json
  • index.js
  • package-lock.json
  • package.json
  • spec.json
  • test/contract.mjs

Download the source artifact (tar.gz)

Source

PROMPT.md
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.readUInt16BE 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.readUInt16BE

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.
csx.json
{"case":{"caseId":"case:sha256:96840389cb55be80d392a64b52d816c04cb3f98eb2e1ef7d53b178bb9b1b51d5","contract":["Buffer.prototype.readUInt16BE is a function aliasing Buffer.prototype.readUint16BE","buf.readUInt16BE() defaults to offset 0 and returns big-endian 16-bit unsigned integer","buf.readUInt16BE(offset) reads 16-bit big-endian unsigned integer at specified byte offset","buf.readUInt16BE throws RangeError when offset is out of bounds, negative, or non-integer","buf.readUInt16BE throws TypeError when offset is not a number"],"goal":"verify Buffer.prototype.readUInt16BE in pkg:npm/bare-buffer@3.7.0","kind":"HOW","packages":["pkg:npm/bare-buffer@3.7.0"],"schemaVersion":1,"symbols":["Buffer.prototype.readUInt16BE"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","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.readUInt16BE"],"verifierAdapter":"node-typescript@1"}
index.js
import { createRequire } from 'node:module';
import path from 'node:path';

const require = createRequire(import.meta.url);

// Ensure binding is available in Node.js environments where require.addon is absent
if (typeof Bare === 'undefined') {
  const nodeBuffer = globalThis.Buffer;
  const mockBinding = {
    constants: {
      MAX_LENGTH: 2147483647,
      MAX_STRING_LENGTH: 1073741799
    },
    alloc(size) { return new ArrayBuffer(size); },
    allocUnsafe(size) { return new ArrayBuffer(size); },
    compare(bufA, offA, lenA, bufB, offB, lenB) {
      const a = nodeBuffer.from(bufA, offA, lenA);
      const b = nodeBuffer.from(bufB, offB, lenB);
      return a.compare(b);
    },
    toStringHex(buf, offset, len) {
      return nodeBuffer.from(buf, offset, len).toString('hex');
    },
    writeHex(buf, offset, len, string) {
      return nodeBuffer.from(buf, offset, len).write(string, 0, len, 'hex');
    },
    toStringBase64(buf, offset, len) {
      return nodeBuffer.from(buf, offset, len).toString('base64');
    },
    writeBase64(buf, offset, len, string) {
      return nodeBuffer.from(buf, offset, len).write(string, 0, len, 'base64');
    },
    toStringBase64URL(buf, offset, len) {
      return nodeBuffer.from(buf, offset, len).toString('base64url');
    },
    writeBase64URL(buf, offset, len, string) {
      return nodeBuffer.from(buf, offset, len).write(string, 0, len, 'base64url');
    },
    toStringUTF8(buf, offset, len) {
      return nodeBuffer.from(buf, offset, len).toString('utf8');
    },
    writeUTF8(buf, offset, len, string) {
      return nodeBuffer.from(buf, offset, len).write(string, 0, len, 'utf8');
    },
    validateUTF8(buf, offset, len) {
      return nodeBuffer.isUtf8 ? nodeBuffer.isUtf8(nodeBuffer.from(buf, offset, len)) : true;
    },
    byteLengthUTF8(string) {
      return nodeBuffer.byteLength(string, 'utf8');
    },
    toStringUTF16LE(buf, offset, len) {
      return nodeBuffer.from(buf, offset, len).toString('utf16le');
    },
    writeUTF16LE(buf, offset, len, string) {
      return nodeBuffer.from(buf, offset, len).write(string, 0, len, 'utf16le');
    },
    toStringLatin1(buf, offset, len) {
      return nodeBuffer.from(buf, offset, len).toString('latin1');
    },
    writeLatin1(buf, offset, len, string) {
      return nodeBuffer.from(buf, offset, len).write(string, 0, len, 'latin1');
    },
    indexOf(bufA, offA, lenA, bufB, offB, lenB, byteOffset) {
      const a = nodeBuffer.from(bufA, offA, lenA);
      const b = nodeBuffer.from(bufB, offB, lenB);
      return a.indexOf(b, byteOffset);
    },
    lastIndexOf(bufA, offA, lenA, bufB, offB, lenB, byteOffset) {
      const a = nodeBuffer.from(bufA, offA, lenA);
      const b = nodeBuffer.from(bufB, offB, lenB);
      return a.lastIndexOf(b, byteOffset);
    },
    swap16(buf, offset, len) {
      nodeBuffer.from(buf, offset, len).swap16();
    },
    swap32(buf, offset, len) {
      nodeBuffer.from(buf, offset, len).swap32();
    },
    swap64(buf, offset, len) {
      nodeBuffer.from(buf, offset, len).swap64();
    }
  };

  const mainPath = require.resolve('bare-buffer');
  const bindingPath = path.join(path.dirname(mainPath), 'binding.js');
  require.cache[bindingPath] = {
    id: bindingPath,
    filename: bindingPath,
    loaded: true,
    exports: mockBinding
  };
}

const Buffer = require('bare-buffer');

export function readUInt16BE(buffer, offset = 0) {
  return buffer.readUInt16BE(offset);
}

export function readUInt16BEArray(buffer, offset = 0, count) {
  const result = [];
  const numElements = count !== undefined ? count : Math.floor((buffer.length - offset) / 2);
  for (let i = 0; i < numElements; i++) {
    result.push(buffer.readUInt16BE(offset + i * 2));
  }
  return result;
}

export { Buffer };
export default Buffer;
package-lock.json
{
  "name": "sample-bare-buffer-read-uint16-be",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-bare-buffer-read-uint16-be",
      "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"
      }
    }
  }
}
package.json
{
  "name": "sample-bare-buffer-read-uint16-be",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "bare-buffer": "3.7.0"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify Buffer.prototype.readUInt16BE in pkg:npm/bare-buffer@3.7.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/bare-buffer@3.7.0"
  ],
  "symbols": [
    "Buffer.prototype.readUInt16BE"
  ]
}
test/contract.mjs
import assert from 'node:assert/strict';
import Buffer, { readUInt16BE, readUInt16BEArray } from '../index.js';

// 1. Buffer.prototype.readUInt16BE exists and aliases readUint16BE
assert.strictEqual(typeof Buffer.prototype.readUInt16BE, 'function', 'readUInt16BE must be a prototype method');
assert.strictEqual(Buffer.prototype.readUInt16BE, Buffer.prototype.readUint16BE, 'readUInt16BE must alias readUint16BE');

// 2. Default offset is 0 and reads big-endian 16-bit unsigned integer
const buf1 = Buffer.from([0x12, 0x34]);
assert.strictEqual(buf1.readUInt16BE(), 0x1234, 'Default offset should read first 2 bytes as big-endian (0x1234 = 4660)');
assert.strictEqual(buf1.readUInt16BE(0), 4660, 'Explicit offset 0 should equal 4660');

// 3. Big-endian byte order verification across numeric boundaries
const maxBuf = Buffer.from([0xff, 0xff]);
assert.strictEqual(maxBuf.readUInt16BE(0), 65535, '0xFFFF should decode to 65535');

const zeroBuf = Buffer.from([0x00, 0x00]);
assert.strictEqual(zeroBuf.readUInt16BE(0), 0, '0x0000 should decode to 0');

const midBuf = Buffer.from([0x80, 0x00]);
assert.strictEqual(midBuf.readUInt16BE(0), 32768, '0x8000 should decode to 32768');

const asymmetryBuf = Buffer.from([0x01, 0x02]);
assert.strictEqual(asymmetryBuf.readUInt16BE(0), 0x0102, '0x01, 0x02 must decode to 0x0102 (258), not little-endian 0x0201 (513)');

// 4. Reading at arbitrary positive offsets in a larger buffer
const multiBuf = Buffer.from([0xaa, 0x12, 0x34, 0x56, 0x78, 0xbb]);
assert.strictEqual(multiBuf.readUInt16BE(1), 0x1234, 'Offset 1 should read 0x1234');
assert.strictEqual(multiBuf.readUInt16BE(3), 0x5678, 'Offset 3 should read 0x5678');
assert.strictEqual(multiBuf.readUInt16BE(4), 0x78bb, 'Offset 4 should read 0x78bb');

// 5. Helper function wrappers
assert.strictEqual(readUInt16BE(multiBuf, 1), 0x1234, 'readUInt16BE helper should read 0x1234 at offset 1');
const seqBuf = Buffer.from([0x00, 0x0a, 0x00, 0x14, 0x00, 0x1e]);
assert.deepStrictEqual(readUInt16BEArray(seqBuf), [10, 20, 30], 'readUInt16BEArray should decode sequence of uint16 BE values');

// 6. RangeError thrown on bounds violation
const smallBuf = Buffer.from([0x01, 0x02]);
assert.throws(() => {
  smallBuf.readUInt16BE(1);
}, { name: 'RangeError' }, 'Offset with less than 2 bytes remaining must throw RangeError');

assert.throws(() => {
  smallBuf.readUInt16BE(2);
}, { name: 'RangeError' }, 'Offset at end of buffer must throw RangeError');

assert.throws(() => {
  smallBuf.readUInt16BE(-1);
}, { name: 'RangeError' }, 'Negative offset must throw RangeError');

const emptyBuf = Buffer.alloc(0);
assert.throws(() => {
  emptyBuf.readUInt16BE(0);
}, { name: 'RangeError' }, 'Reading from empty buffer must throw RangeError');

assert.throws(() => {
  smallBuf.readUInt16BE(0.5);
}, { name: 'RangeError' }, 'Non-integer offset must throw RangeError');

// 7. TypeError thrown on non-numeric offset type
assert.throws(() => {
  smallBuf.readUInt16BE('0');
}, { name: 'TypeError' }, 'String offset must throw TypeError');

assert.throws(() => {
  smallBuf.readUInt16BE(null);
}, { name: 'TypeError' }, 'Null offset must throw TypeError');

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

Origin Seeder

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