prosemirror-changeset 2.4.3

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/prosemirror-changeset@2.4.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/prosemirror-changeset@2.4.3

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:b3968001dbfc9a203fe337333e52b1a1908e4fa6e9dfa94fcd68975fce1954be","contract":["Change and Span represent replaced text ranges with length and metadata","Change.merge merges sequential changesets and combines span metadata","Change.merge cancels out deletions that undo insertions","Change toJSON and Change.fromJSON serialize and deserialize change instances preserving ranges and metadata","ChangeSet.create initializes a change set tracking changes for a document","ChangeSet.map transforms metadata across deleted and inserted spans","ChangeSet.changedRange computes the bounding range of differences between changesets","simplifyChanges preserves non-adjacent changes and handles empty change lists"],"goal":"verify pkg:npm/prosemirror-changeset@2.4.3","kind":"HOW","packages":["pkg:npm/prosemirror-changeset@2.4.3"],"schemaVersion":1},"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/prosemirror-changeset@2.4.3"],"schemaVersion":1,"subject":"pkg:npm/prosemirror-changeset@2.4.3","verifierAdapter":"node-typescript@1"}

import { Change, Span, ChangeSet, simplifyChanges } from 'prosemirror-changeset';

export function createChange(fromA, toA, fromB, toB, deleted, inserted) {
  return new Change(fromA, toA, fromB, toB, deleted, inserted);
}

export function createSpan(length, data) {
  return new Span(length, data);
}

export function mergeChanges(x, y, combine) {
  return Change.merge(x, y, combine);
}

export function createChangeSet(doc, combine, tokenEncoder, changes) {
  return ChangeSet.create(doc, combine, tokenEncoder, changes);
}

export { Change, Span, ChangeSet, simplifyChanges };

{
  "name": "prosemirror-changeset-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "prosemirror-changeset-sample",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "prosemirror-changeset": "2.4.3"
      }
    },
    "node_modules/orderedmap": {
      "version": "2.1.1",
      "resolved": "https://registry.npmjs.org/orderedmap/-/orderedmap-2.1.1.tgz",
      "integrity": "sha512-TvAWxi0nDe1j/rtMcWcIj94+Ffe6n7zhow33h40SKxmsmozs6dz/e+EajymfoFcHd7sxNn8yHM8839uixMOV6g==",
      "license": "MIT"
    },
    "node_modules/prosemirror-changeset": {
      "version": "2.4.3",
      "resolved": "https://registry.npmjs.org/prosemirror-changeset/-/prosemirror-changeset-2.4.3.tgz",
      "integrity": "sha512-J8jqUZ1xybXKY44v3K0c8m8ZTIqJPVT34t2UVyxv4VEWoNd5C9t5Y52GNuMriRJ3IpNxOSE2R60vN4qBrTMcyQ==",
      "license": "MIT",
      "dependencies": {
        "prosemirror-transform": "^1.0.0"
      }
    },
    "node_modules/prosemirror-model": {
      "version": "1.25.11",
      "resolved": "https://registry.npmjs.org/prosemirror-model/-/prosemirror-model-1.25.11.tgz",
      "integrity": "sha512-QWg9RhnpLlogAmp3p96uEFrE5txQpFynd4vhBAELkwgOCWQs/X0yCzB3/hrHqiPwf91RG5KyWq6553zs9JqIOQ==",
      "license": "MIT",
      "dependencies": {
        "orderedmap": "^2.0.0"
      }
    },
    "node_modules/prosemirror-transform": {
      "version": "1.12.1",
      "resolved": "https://registry.npmjs.org/prosemirror-transform/-/prosemirror-transform-1.12.1.tgz",
      "integrity": "sha512-t4F5615FycnCqsX7ShTUs8+jfnwcf46kuFRvSl/3qFx2QTZ4DjgowesLHQXcFP7G//TjesqZG3WtgL7vdyVJyA==",
      "license": "MIT",
      "dependencies": {
        "prosemirror-model": "^1.21.0"
      }
    }
  }
}

{
  "name": "prosemirror-changeset-sample",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification for prosemirror-changeset",
  "type": "module",
  "main": "index.js",
  "license": "MIT-0",
  "dependencies": {
    "prosemirror-changeset": "2.4.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/prosemirror-changeset@2.4.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/prosemirror-changeset@2.4.3"
  ]
}

import assert from 'node:assert';
import { Change, Span, ChangeSet, simplifyChanges } from 'prosemirror-changeset';
import {
  createChange,
  createSpan,
  mergeChanges,
  createChangeSet
} from '../index.js';

// 1. Change and Span represent replaced text ranges with length and metadata
const delSpan = createSpan(5, { id: 'meta-1' });
const insSpan = createSpan(3, { id: 'meta-2' });
assert.strictEqual(delSpan.length, 5);
assert.strictEqual(delSpan.data.id, 'meta-1');
assert.strictEqual(insSpan.length, 3);
assert.strictEqual(insSpan.data.id, 'meta-2');

const change1 = createChange(10, 15, 10, 13, [delSpan], [insSpan]);
assert.strictEqual(change1.fromA, 10);
assert.strictEqual(change1.toA, 15);
assert.strictEqual(change1.fromB, 10);
assert.strictEqual(change1.toB, 13);
assert.strictEqual(change1.lenA, 5);
assert.strictEqual(change1.lenB, 3);
assert.strictEqual(change1.deleted.length, 1);
assert.strictEqual(change1.inserted.length, 1);

// 2. Change.merge merges sequential changesets and combines span metadata
const stepA = [createChange(1, 1, 1, 2, [], [createSpan(1, 'v1')])];
const stepB = [createChange(1, 1, 1, 2, [], [createSpan(1, 'v1')])];
const merged = mergeChanges(stepA, stepB, (a, b) => (a === b ? a : null));
assert.strictEqual(merged.length, 1);
assert.strictEqual(merged[0].fromA, 1);
assert.strictEqual(merged[0].toA, 1);
assert.strictEqual(merged[0].fromB, 1);
assert.strictEqual(merged[0].toB, 3);
assert.strictEqual(merged[0].inserted.length, 1);
assert.strictEqual(merged[0].inserted[0].length, 2);
assert.strictEqual(merged[0].inserted[0].data, 'v1');

// 3. Change.merge cancels out deletions that undo insertions
const insertChange = [createChange(2, 2, 2, 5, [], [createSpan(3, 'temp')])];
const deleteChange = [createChange(2, 5, 2, 2, [createSpan(3, 'temp')], [])];
const canceled = mergeChanges(insertChange, deleteChange, (a, b) => a);
assert.deepStrictEqual(canceled, []);

// 4. Change toJSON and Change.fromJSON serialize and deserialize change instances preserving ranges and metadata
const sampleChange = createChange(4, 9, 4, 11, [createSpan(5, 'removed')], [createSpan(7, 'added')]);
const json = JSON.parse(JSON.stringify(sampleChange.toJSON()));
const restored = Change.fromJSON(json);
assert.strictEqual(restored.fromA, 4);
assert.strictEqual(restored.toA, 9);
assert.strictEqual(restored.fromB, 4);
assert.strictEqual(restored.toB, 11);
assert.strictEqual(restored.deleted.length, 1);
assert.strictEqual(restored.deleted[0].length, 5);
assert.strictEqual(restored.deleted[0].data, 'removed');
assert.strictEqual(restored.inserted.length, 1);
assert.strictEqual(restored.inserted[0].length, 7);
assert.strictEqual(restored.inserted[0].data, 'added');
assert(restored instanceof Change);
assert(restored.deleted[0] instanceof Span);

// 5. ChangeSet.create initializes a change set tracking changes for a document
const docMock = { content: { size: 0, childCount: 0 } };
const changeSet = createChangeSet(docMock, (a, b) => (a === b ? a : null), undefined, [sampleChange]);
assert.strictEqual(changeSet.startDoc, docMock);
assert.strictEqual(changeSet.changes.length, 1);
assert.strictEqual(changeSet.changes[0], sampleChange);

// 6. ChangeSet.map transforms metadata across deleted and inserted spans
const mapped = changeSet.map(span => (typeof span.data === 'string' ? span.data.toUpperCase() : span.data));
assert.strictEqual(mapped.changes[0].deleted[0].data, 'REMOVED');
assert.strictEqual(mapped.changes[0].inserted[0].data, 'ADDED');

// 7. ChangeSet.changedRange computes the bounding range of differences between changesets
const baseChange = createChange(0, 5, 0, 5, [createSpan(5, 'shared')], [createSpan(5, 'shared')]);
const diffA = createChange(10, 15, 10, 15, [createSpan(5, 'delA')], [createSpan(5, 'insA')]);
const diffB = createChange(10, 15, 10, 15, [createSpan(5, 'delB')], [createSpan(5, 'insB')]);
const setA = createChangeSet(docMock, (a, b) => (a === b ? a : null), undefined, [baseChange, diffA]);
const setB = createChangeSet(docMock, (a, b) => (a === b ? a : null), undefined, [baseChange, diffB]);
const diffRange = setA.changedRange(setB);
assert.notStrictEqual(diffRange, null);
assert.strictEqual(diffRange.from, 10);
assert.strictEqual(diffRange.to, 15);
assert.strictEqual(setA.changedRange(setA), null);

// 8. simplifyChanges preserves non-adjacent changes and handles empty change lists
assert.deepStrictEqual(simplifyChanges([], docMock), []);
const singleCharReplacement = createChange(1, 2, 1, 2, [createSpan(1, 'a')], [createSpan(1, 'b')]);
const simplified = simplifyChanges([singleCharReplacement], docMock);
assert.strictEqual(simplified.length, 1);
assert.strictEqual(simplified[0], singleCharReplacement);

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