pretty-format 27.5.1: DEFAULT_OPTIONS

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 pretty-format.DEFAULT_OPTIONS in pkg:npm/pretty-format@27.5.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/pretty-format@27.5.1
Demonstrate these symbols/APIs:
  - pretty-format.DEFAULT_OPTIONS

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:sha256:9aff184435abedf605e55d8cf01a304e40a204358394084596a174596bc728f3","contract":["DEFAULT_OPTIONS exposes baseline formatting configuration with standard defaults","getDefaultOptions returns a clone matching DEFAULT_OPTIONS","isValidOptionKey validates option keys against DEFAULT_OPTIONS properties","formatValue formats objects using default two-space indentation and properties","formatValue supports custom option overrides including min and indent","formatValue throws an error when unknown option keys not in DEFAULT_OPTIONS are provided","formatValue respects the default callToJSON option"],"goal":"verify pretty-format.DEFAULT_OPTIONS in pkg:npm/pretty-format@27.5.1","kind":"HOW","packages":["pkg:npm/pretty-format@27.5.1"],"schemaVersion":1,"symbols":["pretty-format.DEFAULT_OPTIONS"]},"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/pretty-format@27.5.1"],"schemaVersion":1,"subject":"pkg:npm/pretty-format@27.5.1","symbols":["pretty-format.DEFAULT_OPTIONS"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-pretty-format-default-options",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pretty-format-default-options",
      "version": "1.0.0",
      "dependencies": {
        "pretty-format": "27.5.1"
      }
    },
    "node_modules/ansi-regex": {
      "version": "5.0.1",
      "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-5.0.1.tgz",
      "integrity": "sha512-quJQXlTSUGL2LH9SUXo8VwsY4soanhgo6LNSm84E1LBcE8s3O0wpdiRzyR9z/ZZJMlMWv37qOOb9pdJlMUEKFQ==",
      "license": "MIT",
      "engines": {
        "node": ">=8"
      }
    },
    "node_modules/ansi-styles": {
      "version": "5.2.0",
      "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-5.2.0.tgz",
      "integrity": "sha512-Cxwpt2SfTzTtXcfOlzGEee8O+c+MmUgGrNiBcXnuWxuFJHe6a5Hz7qwhwe5OgaSYI0IJvkLqWX1ASG+cJOkEiA==",
      "license": "MIT",
      "engines": {
        "node": ">=10"
      },
      "funding": {
        "url": "https://github.com/chalk/ansi-styles?sponsor=1"
      }
    },
    "node_modules/pretty-format": {
      "version": "27.5.1",
      "resolved": "https://registry.npmjs.org/pretty-format/-/pretty-format-27.5.1.tgz",
      "integrity": "sha512-Qb1gy5OrP5+zDf2Bvnzdl3jsTf1qXVMazbvCoKhtKqVs4/YK4ozX4gKQJJVyNe+cajNPn0KoC0MC3FUmaHWEmQ==",
      "license": "MIT",
      "dependencies": {
        "ansi-regex": "^5.0.1",
        "ansi-styles": "^5.0.0",
        "react-is": "^17.0.1"
      },
      "engines": {
        "node": "^10.13.0 || ^12.13.0 || ^14.15.0 || >=15.0.0"
      }
    },
    "node_modules/react-is": {
      "version": "17.0.2",
      "resolved": "https://registry.npmjs.org/react-is/-/react-is-17.0.2.tgz",
      "integrity": "sha512-w2GsyukL62IJnlaff/nRegPQR94C/XXamvMWmSHRJ4y7Ts/4ocGRmTHvOs8PSE6pB3dWOrD/nueuU5sduBsQ4w==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-pretty-format-default-options",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of pretty-format.DEFAULT_OPTIONS",
  "main": "src/index.js",
  "dependencies": {
    "pretty-format": "27.5.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pretty-format.DEFAULT_OPTIONS in pkg:npm/pretty-format@27.5.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pretty-format@27.5.1"
  ],
  "symbols": [
    "pretty-format.DEFAULT_OPTIONS"
  ]
}

const { DEFAULT_OPTIONS, format } = require('pretty-format');

/**
 * Returns a shallow copy of the default formatting options.
 * @returns {typeof DEFAULT_OPTIONS}
 */
function getDefaultOptions() {
  return { ...DEFAULT_OPTIONS };
}

/**
 * Formats a given value using pretty-format with custom options merged over defaults.
 * @param {unknown} value - Value to format.
 * @param {object} [options] - Optional custom options.
 * @returns {string}
 */
function formatValue(value, options) {
  return format(value, options);
}

/**
 * Checks whether a given configuration key is a recognized option in DEFAULT_OPTIONS.
 * @param {string} key - Option key name to validate.
 * @returns {boolean}
 */
function isValidOptionKey(key) {
  return Object.prototype.hasOwnProperty.call(DEFAULT_OPTIONS, key);
}

module.exports = {
  DEFAULT_OPTIONS,
  getDefaultOptions,
  formatValue,
  isValidOptionKey
};

import assert from 'node:assert';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const {
  DEFAULT_OPTIONS,
  getDefaultOptions,
  formatValue,
  isValidOptionKey
} = require('../src/index.js');

// 1. DEFAULT_OPTIONS export structure
assert.strictEqual(typeof DEFAULT_OPTIONS, 'object', 'DEFAULT_OPTIONS must be an object');
assert.strictEqual(DEFAULT_OPTIONS.indent, 2, 'DEFAULT_OPTIONS.indent must be 2');
assert.strictEqual(DEFAULT_OPTIONS.callToJSON, true, 'DEFAULT_OPTIONS.callToJSON must be true');
assert.strictEqual(DEFAULT_OPTIONS.escapeString, true, 'DEFAULT_OPTIONS.escapeString must be true');
assert.strictEqual(DEFAULT_OPTIONS.escapeRegex, false, 'DEFAULT_OPTIONS.escapeRegex must be false');
assert.strictEqual(DEFAULT_OPTIONS.highlight, false, 'DEFAULT_OPTIONS.highlight must be false');
assert.strictEqual(DEFAULT_OPTIONS.min, false, 'DEFAULT_OPTIONS.min must be false');
assert.strictEqual(DEFAULT_OPTIONS.maxDepth, Infinity, 'DEFAULT_OPTIONS.maxDepth must be Infinity');
assert.strictEqual(DEFAULT_OPTIONS.compareKeys, undefined, 'DEFAULT_OPTIONS.compareKeys must be undefined');
assert.strictEqual(DEFAULT_OPTIONS.printBasicPrototype, true, 'DEFAULT_OPTIONS.printBasicPrototype must be true');
assert.strictEqual(DEFAULT_OPTIONS.printFunctionName, true, 'DEFAULT_OPTIONS.printFunctionName must be true');
assert.deepStrictEqual(DEFAULT_OPTIONS.plugins, [], 'DEFAULT_OPTIONS.plugins must be an empty array');
assert.deepStrictEqual(DEFAULT_OPTIONS.theme, {
  comment: 'gray',
  content: 'reset',
  prop: 'yellow',
  tag: 'cyan',
  value: 'green'
}, 'DEFAULT_OPTIONS.theme must have standard default theme keys');

// 2. getDefaultOptions helper returns a valid clone
const clonedDefaults = getDefaultOptions();
assert.deepStrictEqual(clonedDefaults, DEFAULT_OPTIONS);
assert.notStrictEqual(clonedDefaults, DEFAULT_OPTIONS);

// 3. isValidOptionKey uses DEFAULT_OPTIONS to recognize valid options
assert.strictEqual(isValidOptionKey('indent'), true);
assert.strictEqual(isValidOptionKey('callToJSON'), true);
assert.strictEqual(isValidOptionKey('compareKeys'), true);
assert.strictEqual(isValidOptionKey('plugins'), true);
assert.strictEqual(isValidOptionKey('nonExistentOption'), false);

// 4. Default formatting behavior
const testObj = {
  active: true,
  count: 10,
  label: 'sample'
};
const defaultOutput = formatValue(testObj);
assert.strictEqual(
  defaultOutput,
  'Object {\n  "active": true,\n  "count": 10,\n  "label": "sample",\n}'
);

// 5. Custom option override respects formatting options
const minifiedOutput = formatValue(testObj, { min: true });
assert.strictEqual(minifiedOutput, '{"active": true, "count": 10, "label": "sample"}');

const indent4Output = formatValue({ key: 'val' }, { indent: 4 });
assert.strictEqual(indent4Output, 'Object {\n    "key": "val",\n}');

// 6. Unknown options rejection based on DEFAULT_OPTIONS schema
assert.throws(
  () => formatValue(testObj, { invalidKey: true }),
  /pretty-format: Unknown option "invalidKey"\./
);

// 7. callToJSON behavior
const objWithToJSON = {
  secret: 'hide',
  toJSON() {
    return { visible: true };
  }
};
assert.strictEqual(
  formatValue(objWithToJSON),
  'Object {\n  "visible": true,\n}'
);
assert.strictEqual(
  formatValue(objWithToJSON, { callToJSON: false }),
  'Object {\n  "secret": "hide",\n  "toJSON": [Function toJSON],\n}'
);

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