parse-conflict-json 4.0.0: isDiff

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 parse-conflict-json.isDiff in pkg:npm/parse-conflict-json@4.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/parse-conflict-json@4.0.0
Demonstrate these symbols/APIs:
  - parse-conflict-json.isDiff

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:sha256:6ec33f9131b01fedea82c8b27cf3731ef10b7ac0d704f9a04bcf7c7c7d65143c","contract":["parse-conflict-json assigns isDiff onto module.exports via Object.assign, so ES modules access it from the default export (parseConflictJson.isDiff)","isDiff(str) returns the closing-marker RegExp match array from str.match(/\u003e{7,}/g) (e.g. ['\u003e\u003e\u003e\u003e\u003e\u003e\u003e']) rather than boolean true when all three conflict markers (\u003c{7,}, ={7,}, \u003e{7,}) are present","isDiff(str) matches markers of 7 or more characters and returns one element per closing marker block when multiple conflicts exist","isDiff(str) short-circuits and returns null (not false) for clean JSON, when any of the three markers is absent, or when a marker has fewer than 7 characters","isDiff(value) throws TypeError when passed a non-string value without a .match method such as null, undefined, or a number"],"goal":"verify parse-conflict-json.isDiff in pkg:npm/parse-conflict-json@4.0.0","kind":"HOW","packages":["pkg:npm/parse-conflict-json@4.0.0"],"schemaVersion":1,"symbols":["parse-conflict-json.isDiff"]},"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/parse-conflict-json@4.0.0"],"schemaVersion":1,"subject":"pkg:npm/parse-conflict-json@4.0.0","symbols":["parse-conflict-json.isDiff"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-parse-conflict-json-isdiff",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-parse-conflict-json-isdiff",
      "version": "1.0.0",
      "dependencies": {
        "parse-conflict-json": "4.0.0"
      }
    },
    "node_modules/json-parse-even-better-errors": {
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/json-parse-even-better-errors/-/json-parse-even-better-errors-4.0.0.tgz",
      "integrity": "sha512-lR4MXjGNgkJc7tkQ97kb2nuEMnNCyU//XYVH0MKTGcXEiSudQ5MKGKen3C5QubYy0vmq+JGitUg92uuywGEwIA==",
      "license": "MIT",
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    },
    "node_modules/just-diff": {
      "version": "6.0.2",
      "resolved": "https://registry.npmjs.org/just-diff/-/just-diff-6.0.2.tgz",
      "integrity": "sha512-S59eriX5u3/QhMNq3v/gm8Kd0w8OS6Tz2FS1NG4blv+z0MuQcBRJyFWjdovM0Rad4/P4aUPFtnkNjMjyMlMSYA==",
      "license": "MIT"
    },
    "node_modules/just-diff-apply": {
      "version": "5.5.0",
      "resolved": "https://registry.npmjs.org/just-diff-apply/-/just-diff-apply-5.5.0.tgz",
      "integrity": "sha512-OYTthRfSh55WOItVqwpefPtNt2VdKsq5AnAK6apdtR6yCH8pr0CmSr710J0Mf+WdQy7K/OzMy7K2MgAfdQURDw==",
      "license": "MIT"
    },
    "node_modules/parse-conflict-json": {
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/parse-conflict-json/-/parse-conflict-json-4.0.0.tgz",
      "integrity": "sha512-37CN2VtcuvKgHUs8+0b1uJeEsbGn61GRHz469C94P5xiOoqpDYJYwjg4RY9Vmz39WyZAVkR5++nbJwLMIgOCnQ==",
      "license": "ISC",
      "dependencies": {
        "json-parse-even-better-errors": "^4.0.0",
        "just-diff": "^6.0.0",
        "just-diff-apply": "^5.2.0"
      },
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    }
  }
}

{
  "name": "sample-parse-conflict-json-isdiff",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "dependencies": {
    "parse-conflict-json": "4.0.0"
  },
  "scripts": {
    "test": "node test/contract.mjs"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify parse-conflict-json.isDiff in pkg:npm/parse-conflict-json@4.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/parse-conflict-json@4.0.0"
  ],
  "symbols": [
    "parse-conflict-json.isDiff"
  ]
}

import assert from 'node:assert/strict';
import parseConflictJson from 'parse-conflict-json';

const { isDiff } = parseConflictJson;
assert.equal(typeof parseConflictJson, 'function');
assert.equal(typeof isDiff, 'function');

// 1. Standard 2-way or 3-way git conflict markers return the closing marker regex match array
const conflictJson = [
  '{',
  '<<<<<<< HEAD',
  '  "version": "1.0.0"',
  '||||||| parent',
  '  "version": "0.9.0"',
  '=======',
  '  "version": "1.1.0"',
  '>>>>>>> feature',
  '}'
].join('\n');

const singleMatch = isDiff(conflictJson);
assert.ok(Array.isArray(singleMatch));
assert.deepEqual(singleMatch, ['>>>>>>>']);

// 2. Multiple conflict blocks in one string return all closing marker matches
const multiConflictJson = [
  '<<<<<<< HEAD',
  '{"a": 1}',
  '=======',
  '{"a": 2}',
  '>>>>>>> branch-a',
  '<<<<<<< HEAD',
  '{"b": 1}',
  '=======',
  '{"b": 2}',
  '>>>>>>> branch-b'
].join('\n');
assert.deepEqual(isDiff(multiConflictJson), ['>>>>>>>', '>>>>>>>']);

// 3. Markers with 7 or more characters (e.g. 8 chars) also match
const extendedMarkers = '<<<<<<<<\n{"x":1}\n========\n{"x":2}\n>>>>>>>>\n';
assert.deepEqual(isDiff(extendedMarkers), ['>>>>>>>>']);

// 4. Clean JSON or partial/short markers (< 7 chars) short-circuit and return null
assert.equal(isDiff('{"name": "example", "version": "1.0.0"}'), null);
assert.equal(isDiff('<<<<<<< HEAD\n{"a": 1}\n=======\n{"a": 2}'), null);
assert.equal(isDiff('<<<<<<< HEAD\n{"a": 1}\n>>>>>>> branch'), null);
assert.equal(isDiff('{"a": 1}\n=======\n{"a": 2}\n>>>>>>> branch'), null);
assert.equal(isDiff('<<<<<<\n{"a": 1}\n=======\n{"a": 2}\n>>>>>>>'), null);

// 5. Non-string inputs without .match throw TypeError
assert.throws(() => isDiff(null), TypeError);
assert.throws(() => isDiff(undefined), TypeError);
assert.throws(() => isDiff(42), TypeError);