jsonfile 4.0.0: readFileSync, writeFileSync

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 pkg:npm/jsonfile@4.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/jsonfile@4.0.0
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:sha256:6ceb292542425b9dc325d1beac25fda9d9e486fad0d36ddbd983db239d44660e","constraints":{"executionContext":"node"},"contract":["jsonfile.writeFileSync writes an object to a file as JSON","jsonfile.readFileSync reads and parses JSON from a file synchronously"],"goal":"verify pkg:npm/jsonfile@4.0.0","kind":"HOW","packages":["pkg:npm/jsonfile@4.0.0"],"schemaVersion":1,"symbols":["readFileSync","writeFileSync"]},"contractCommand":["node","test/contract.cjs"],"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/jsonfile@4.0.0"],"schemaVersion":1,"subject":"pkg:npm/jsonfile@4.0.0","symbols":["readFileSync","writeFileSync"],"verifierAdapter":"node-typescript@1"}

const jsonfile = require('jsonfile');

function writeConfig(filePath, data) {
  jsonfile.writeFileSync(filePath, data, { spaces: 2 });
}

function readConfig(filePath) {
  return jsonfile.readFileSync(filePath);
}

module.exports = {
  writeConfig,
  readConfig
};

{
  "name": "sample-jsonfile-verify",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-jsonfile-verify",
      "version": "1.0.0",
      "dependencies": {
        "jsonfile": "4.0.0"
      }
    },
    "node_modules/graceful-fs": {
      "version": "4.2.11",
      "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.11.tgz",
      "integrity": "sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ==",
      "license": "ISC",
      "optional": true
    },
    "node_modules/jsonfile": {
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
      "integrity": "sha512-m6F1R3z8jjlf2imQHS2Qez5sjKWQzbuuhuJ/FKYFRZvPE3PuHcSMVZzfsLhGVOkfd20obL5SWEBew5ShlquNxg==",
      "license": "MIT",
      "optionalDependencies": {
        "graceful-fs": "^4.1.6"
      }
    }
  }
}

{
  "name": "sample-jsonfile-verify",
  "version": "1.0.0",
  "private": true,
  "description": "verify pkg:npm/jsonfile@4.0.0",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.cjs"
  },
  "dependencies": {
    "jsonfile": "4.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/jsonfile@4.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/jsonfile@4.0.0"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

const assert = require('assert');
const fs = require('fs');
const path = require('path');
const os = require('os');
const jsonfile = require('jsonfile');
const { writeConfig, readConfig } = require('../index.js');

const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'jsonfile-test-'));
const filePath = path.join(tmpDir, 'test.json');

try {
  const originalData = {
    title: "sample",
    version: "1.0.0",
    enabled: true,
    count: 42,
    nested: {
      key: "value"
    }
  };

  writeConfig(filePath, originalData);
  assert.strictEqual(fs.existsSync(filePath), true, 'File should exist after write');

  const rawContent = fs.readFileSync(filePath, 'utf8');
  assert.deepStrictEqual(JSON.parse(rawContent), originalData, 'Raw JSON should match original data');

  const readData = readConfig(filePath);
  assert.deepStrictEqual(readData, originalData, 'Read data should deep strict equal original data');

  const directPath = path.join(tmpDir, 'direct.json');
  jsonfile.writeFileSync(directPath, { direct: true });
  const directData = jsonfile.readFileSync(directPath);
  assert.strictEqual(directData.direct, true);

  console.log('Contract tests passed successfully.');
  process.exit(0);
} finally {
  try {
    fs.rmSync(tmpDir, { recursive: true, force: true });
  } catch (e) {
    // Ignore cleanup error
  }
}