parse-conflict-json 4.0.0: parseConflictJson

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 parseConflictJson 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:
  - parseConflictJson

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:sha256:5eb226814e0360da5a067efe67921af12d4dc83cdec07ba9d8f1af9de039e123","contract":["parseConflictJson parses plain JSON without conflict markers and parseConflictJson.isDiff returns falsy","parseConflictJson resolves diff3-style JSON conflicts (\u003c{7}, |{7}, ={7}, \u003e{7}) preferring 'ours' by default or 'theirs' when specified","parseConflictJson applies an optional JSON reviver to parent, ours, and theirs branches before merging","parseConflictJson throws TypeError when prefer is neither 'ours' nor 'theirs'"],"goal":"verify parseConflictJson in pkg:npm/parse-conflict-json@4.0.0","kind":"HOW","packages":["pkg:npm/parse-conflict-json@4.0.0"],"schemaVersion":1,"symbols":["parseConflictJson"]},"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":["parseConflictJson"],"verifierAdapter":"node-typescript@1"}

{
  "name": "verify-parse-conflict-json",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "verify-parse-conflict-json",
      "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": "verify-parse-conflict-json",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "dependencies": {
    "parse-conflict-json": "4.0.0"
  }
}

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

import parseConflictJson from 'parse-conflict-json';

export function resolveConflictJson(jsonText, reviver, prefer) {
  return parseConflictJson(jsonText, reviver, prefer);
}

export function detectConflictMarkers(jsonText) {
  return Boolean(parseConflictJson.isDiff(jsonText));
}

import assert from 'node:assert/strict';
import parseConflictJson from 'parse-conflict-json';
import { resolveConflictJson, detectConflictMarkers } from '../src/index.mjs';

const toPlainObject = (obj) => JSON.parse(JSON.stringify(obj));

// 1. Plain JSON without conflict markers
const cleanJson = '{"version": "1.0.0", "items": [1, 2]}';
assert.equal(detectConflictMarkers(cleanJson), false);
const parsedClean = resolveConflictJson(cleanJson);
assert.deepEqual(toPlainObject(parsedClean), { version: '1.0.0', items: [1, 2] });
assert.equal(parsedClean[Symbol.for('indent')], '');
assert.equal(parsedClean[Symbol.for('newline')], '');

// 2. Diff3-style 3-way conflict resolution
const conflictedJson = [
  '{',
  '<<<<<<< HEAD',
  '  "mode": "ours",',
  '  "oursField": 100',
  '||||||| base',
  '  "mode": "base"',
  '=======',
  '  "mode": "theirs",',
  '  "theirsField": 200',
  '>>>>>>> feature',
  '}'
].join('\n');

assert.equal(detectConflictMarkers(conflictedJson), true);

// Default prefer is 'ours'
const mergedOurs = resolveConflictJson(conflictedJson);
assert.deepEqual(toPlainObject(mergedOurs), {
  mode: 'ours',
  oursField: 100,
  theirsField: 200
});

// Explicit prefer 'theirs'
const mergedTheirs = resolveConflictJson(conflictedJson, null, 'theirs');
assert.deepEqual(toPlainObject(mergedTheirs), {
  mode: 'theirs',
  oursField: 100,
  theirsField: 200
});

// 3. Custom JSON reviver applied across conflict branches
const mergedRevived = parseConflictJson(
  conflictedJson,
  (_key, val) => (typeof val === 'number' ? val + 5 : val),
  'ours'
);
assert.deepEqual(toPlainObject(mergedRevived), {
  mode: 'ours',
  oursField: 105,
  theirsField: 205
});

// 4. Invalid prefer argument throws TypeError
assert.throws(
  () => parseConflictJson(cleanJson, null, 'unknown'),
  {
    name: 'TypeError',
    message: /prefer param must be "ours" or "theirs" if set/
  }
);