CodeSampleX

Sample

fflate 0.8.3: inflateSync

Verified sample for npm fflate 0.8.3: inflateSync. The contract ran on node 22 · linux debian/x64 · docker and passed: assert inflateSync decompresses valid…

sha256:72e4dfabf6d6a731a3f9147475407a5ca0eae12454879e86b93e701d4f144df3

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 node 22.23 linux 24 · ubuntu · glibc 2.39 x64 node 22.23 javascript npm 10

Verification-run environments

Environment Contract Stages Run
node 22 · linux debian/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22@sha256:8a34c4ab3ea2…
2026-09-19

Case

HOW
Goal
verify fflate.inflateSync in pkg:npm/fflate@0.8.3
Packages
Symbols
  • fflate.inflateSync
Environment
node 22.23.2
Created
2026-09-17T19:48:35Z

Contract

  1. assert inflateSync decompresses valid DEFLATE data and returns a Uint8Array
  2. assert inflateSync accurately restores original string content compressed with deflateSync
  3. assert inflateSync decompresses empty DEFLATE payload into an empty Uint8Array
  4. assert inflateSync successfully decompresses large repetitive data
  5. assert inflateSync throws an error when given invalid or corrupted deflate data

Files

  • PROMPT.md
  • csx.json
  • index.mjs
  • 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 fflate.inflateSync in pkg:npm/fflate@0.8.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/fflate@0.8.3
Demonstrate these symbols/APIs:
  - fflate.inflateSync

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:sha256:57e7ffed24d3233b91c085a453e65a66a53907dfc136b8f492c8c6a0d34d10fa","contract":["assert inflateSync decompresses valid DEFLATE data and returns a Uint8Array","assert inflateSync accurately restores original string content compressed with deflateSync","assert inflateSync decompresses empty DEFLATE payload into an empty Uint8Array","assert inflateSync successfully decompresses large repetitive data","assert inflateSync throws an error when given invalid or corrupted deflate data"],"goal":"verify fflate.inflateSync in pkg:npm/fflate@0.8.3","kind":"HOW","packages":["pkg:npm/fflate@0.8.3"],"schemaVersion":1,"symbols":["fflate.inflateSync"]},"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/fflate@0.8.3"],"schemaVersion":1,"subject":"pkg:npm/fflate@0.8.3","symbols":["fflate.inflateSync"],"verifierAdapter":"node-typescript@1"}
index.mjs
import { inflateSync, deflateSync } from 'fflate';

/**
 * Decompresses raw DEFLATE data synchronously.
 *
 * @param {Uint8Array} data - The compressed DEFLATE bytes.
 * @param {object} [opts] - Decompression options.
 * @returns {Uint8Array} The decompressed bytes.
 */
export function decompressDeflateSync(data, opts) {
  return inflateSync(data, opts);
}

/**
 * Compresses data synchronously using raw DEFLATE format.
 *
 * @param {Uint8Array} data - The uncompressed input bytes.
 * @param {object} [opts] - Compression options.
 * @returns {Uint8Array} The compressed DEFLATE bytes.
 */
export function compressDeflateSync(data, opts) {
  return deflateSync(data, opts);
}

export { inflateSync, deflateSync };
export default inflateSync;
package-lock.json
{
  "name": "sample-fflate-inflatesync",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-fflate-inflatesync",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "fflate": "0.8.3"
      }
    },
    "node_modules/fflate": {
      "version": "0.8.3",
      "resolved": "https://registry.npmjs.org/fflate/-/fflate-0.8.3.tgz",
      "integrity": "sha512-tbZNuJrLwGUp3zshBtdy4W+ORxZuIh8a5ilyIEQDC5rY1f3U20JMry0Ll3WBzU58EZKsEuJFXhb5gwv8CsPvgA==",
      "license": "MIT"
    }
  }
}
package.json
{
  "name": "sample-fflate-inflatesync",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "fflate": "0.8.3"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify fflate.inflateSync in pkg:npm/fflate@0.8.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/fflate@0.8.3"
  ],
  "symbols": [
    "fflate.inflateSync"
  ]
}
test/contract.mjs
import assert from 'node:assert/strict';
import { inflateSync, deflateSync, decompressDeflateSync, compressDeflateSync } from '../index.mjs';

// 1. assert inflateSync decompresses valid DEFLATE data and returns a Uint8Array
{
  const input = new TextEncoder().encode('Hello CodeSampleX inflateSync test!');
  const compressed = compressDeflateSync(input);
  const decompressed = decompressDeflateSync(compressed);
  assert.ok(decompressed instanceof Uint8Array, 'inflateSync must return a Uint8Array');
  assert.ok(decompressed.length > 0, 'decompressed output must not be empty');
}

// 2. assert inflateSync accurately restores original string content compressed with deflateSync
{
  const message = 'The quick brown fox jumps over the lazy dog. 1234567890!@#$%^&*()';
  const input = new TextEncoder().encode(message);
  const compressed = deflateSync(input);
  const decompressed = inflateSync(compressed);
  const restoredText = new TextDecoder().decode(decompressed);
  assert.strictEqual(restoredText, message, 'decompressed string content must match original input text exactly');
  assert.deepStrictEqual(decompressed, input, 'decompressed bytes must match original input bytes');
}

// 3. assert inflateSync decompresses empty DEFLATE payload into an empty Uint8Array
{
  const emptyInput = new Uint8Array(0);
  const compressed = deflateSync(emptyInput);
  const decompressed = inflateSync(compressed);
  assert.ok(decompressed instanceof Uint8Array, 'inflateSync must return a Uint8Array for empty payload');
  assert.strictEqual(decompressed.length, 0, 'decompressed empty payload must have length 0');
}

// 4. assert inflateSync successfully decompresses large repetitive data
{
  const repetitive = new TextEncoder().encode('ABCDEF1234567890'.repeat(500));
  const compressed = deflateSync(repetitive, { level: 9 });
  const decompressed = inflateSync(compressed);
  assert.deepStrictEqual(decompressed, repetitive, 'large repetitive decompressed data must match original bytes');
  assert.strictEqual(decompressed.length, repetitive.length, 'decompressed length must match original length');
}

// 5. assert inflateSync throws an error when given invalid or corrupted deflate data
{
  const invalidData = new Uint8Array([0x00, 0x01, 0x02, 0x03, 0x04]);
  assert.throws(
    () => {
      inflateSync(invalidData);
    },
    (err) => {
      return err instanceof Error;
    },
    'inflateSync must throw an error when provided with invalid deflate data'
  );
}

console.log('All contract assertions passed.');

Origin Seeder

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