JSON CRDT Repo by streamich · Pull Request #1018 · streamich/json-joy

streamich · 2026-04-15T17:38:30Z

Implementation of browser client and storage for JSON CRDT documents.

Copilot

Pull request overview

This PR introduces a new @jsonjoy.com/json-crdt-repo package (browser local-first client + storage + sync for JSON CRDT docs) and includes several related correctness/test-harness improvements across the monorepo.

Changes:

Add the json-crdt-repo package with local LevelDB-backed repo, remote history adapter, editing sessions, pubsub, utilities, demos, and extensive Jest/e2e tests.
Improve CRDT/NFS robustness (handle missing array children during sync replays; expand NFS errno→NFSv4 status mappings + tests; reduce noisy logging).
Harden server/test infrastructure (clone return values from in-memory block store; refine block deletion pubsub emission; add more deterministic cleanup in multiple test suites; refactor reconnect delay handling).

Reviewed changes

Copilot reviewed 83 out of 85 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
yarn.lock	Add workspace entry for new `@jsonjoy.com/json-crdt-repo` package and adjust workspace resolution entries.
packages/json-pack/src/nfs/v4/server/operations/node/util.ts	Expand Node FS errno normalization to additional NFSv4 status codes.
packages/json-pack/src/nfs/v4/server/operations/node/tests/REMOVE.spec.ts	Add test coverage for non-empty directory removal returning `NOTEMPTY`.
packages/json-pack/src/nfs/v4/server/operations/node/tests/READLINK.spec.ts	Tighten READLINK non-symlink assertion to expect `INVAL`.
packages/json-pack/src/nfs/v4/server/operations/node/Nfsv4OperationsNode.ts	Gate ILLEGAL operation logging behind `debug` flag.
packages/json-joy/src/json-crdt/nodes/arr/ArrNode.ts	Avoid crashing when array child IDs are missing from index during iteration.
packages/json-joy/src/json-crdt/model/tests/Model.sync.spec.ts	Add regression test for sparse concurrent history replay without missing-child crash.
packages/json-joy/src/json-crdt/tests/fuzzer2/sync-ops.spec.ts	Factor fuzzer loop into helper + add fixed failing seed regression.
packages/json-crdt-server/src/services/blocks/store/MemoryStore.ts	Return deep-cloned block/snapshot/batch/patch objects to prevent external mutation.
packages/json-crdt-server/src/services/blocks/BlocksServices.ts	Refactor block event emission helpers and only emit deletion when actually deleted.
packages/json-crdt-repo/tsconfig.json	New package TS config + project references.
packages/json-crdt-repo/tsconfig.build.json	New package build TS config + build references.
packages/json-crdt-repo/src/util/rx/shareByKey.ts	Add keyed observable sharing helper for per-id subscriptions.
packages/json-crdt-repo/src/util/tests/Mutex.spec.ts	Add tests for new keyed async mutex behavior.
packages/json-crdt-repo/src/util/Mutex.ts	Add keyed async mutex implementation.
packages/json-crdt-repo/src/undo-redo/UndoRedoStack.ts	Add undo/redo stack abstraction with locking + timeout handling.
packages/json-crdt-repo/src/types.ts	Add top-level repo/session history typing surface.
packages/json-crdt-repo/src/session/types.ts	Define session history service and sync request/response types.
packages/json-crdt-repo/src/session/index.ts	Export session APIs.
packages/json-crdt-repo/src/session/tests/setup.ts	Add session test setup around local level testbed.
packages/json-crdt-repo/src/session/tests/EditSessionFactory.spec.ts	Add comprehensive tests for session factory make/load and remote interactions.
packages/json-crdt-repo/src/session/tests/EditSession.two-sessions.spec.ts	Add tests for two-session convergence across remote/local/same-tab scenarios.
packages/json-crdt-repo/src/session/tests/EditSession.sync.spec.ts	Add tests for sync semantics (log draining, convergence, timing predictability).
packages/json-crdt-repo/src/session/tests/EditSession.onFlush.spec.ts	Add tests for onFlush-driven synchronization across sessions.
packages/json-crdt-repo/src/session/tests/EditSession.events.spec.ts	Add tests for rebase events and `.applyLocalPatch()` flow.
packages/json-crdt-repo/src/session/tests/EditSession.del.spec.ts	Add tests for deletion propagation across sessions/tabs/remote.
packages/json-crdt-repo/src/session/tests/EditSession.JsonPatch.spec.ts	Add tests for JSON Patch interface behavior across sessions.
packages/json-crdt-repo/src/session/EditSessionFactory.ts	Implement session factory (make/load) including optional remote pull logic.
packages/json-crdt-repo/src/session/EditSession.ts	Implement edit session lifecycle, sync, and event integration with local repo.
packages/json-crdt-repo/src/remote/types.ts	Define `RemoteHistory` abstraction + server-specialized aliases.
packages/json-crdt-repo/src/remote/index.ts	Export remote APIs.
packages/json-crdt-repo/src/remote/tests/setup.ts	Add remote test setup using server caller.
packages/json-crdt-repo/src/remote/tests/DemoServerRemoteHistory.spec.ts	Add tests validating remote history adapter behavior over server routes.
packages/json-crdt-repo/src/remote/DemoServerRemoteHistory.ts	Implement remote history adapter backed by JSON CRDT server RPC routes.
packages/json-crdt-repo/src/pubsub/types.ts	Define pubsub interface.
packages/json-crdt-repo/src/pubsub/index.ts	Implement in-memory + BroadcastChannel pubsub for cross-tab messaging.
packages/json-crdt-repo/src/pubsub/tests/index.spec.ts	Add tests for cross-instance pubsub behavior.
packages/json-crdt-repo/src/local/types.ts	Define local repo CRUD/sync/pull/change event types.
packages/json-crdt-repo/src/local/level/types.ts	Define LevelDB local repo storage types + pubsub message shapes.
packages/json-crdt-repo/src/local/level/tests/setup.ts	Add LevelLocalRepo test harness using MemoryLevel + server remote.
packages/json-crdt-repo/src/local/level/tests/LevelLocalRepo.remote-sync.spec.ts	Add tests for resuming sync after connectivity changes / new tab online.
packages/json-crdt-repo/src/local/level/tests/LevelLocalRepo.pull.spec.ts	Add tests for pull idempotency, conflict handling, reset strategy, and events.
packages/json-crdt-repo/src/local/level/tests/LevelLocalRepo.events.spec.ts	Add tests for pubsub-driven cross-tab events (including rebase).
packages/json-crdt-repo/src/local/level/README.md	Add minimal documentation for LevelDB-backed local repo.
packages/json-crdt-repo/src/local/index.ts	Export local repo APIs.
packages/json-crdt-repo/src/index.ts	Package entrypoint exports.
packages/json-crdt-repo/src/tests/types.ts	Add shared test setup typings for e2e-like suites.
packages/json-crdt-repo/src/tests/testbed.ts	Add browser/tab/repo testbed abstraction for multi-tab scenarios.
packages/json-crdt-repo/src/tests/setup.ts	Add server-backed setup helpers (memory/level stores) for RPC tests.
packages/json-crdt-repo/src/tests/server/util.ts	Add RPC util route tests.
packages/json-crdt-repo/src/tests/server/pubsub.ts	Add RPC pubsub route tests.
packages/json-crdt-repo/src/tests/server/presence.ts	Add RPC presence route tests.
packages/json-crdt-repo/src/tests/server/block.ts	Add extensive RPC block route tests.
packages/json-crdt-repo/src/tests/e2e/run.ts	Add runner to start server + execute Jest e2e tests.
packages/json-crdt-repo/src/tests/e2e/json-crdt-server/demo-server.spec.ts	Add optional demo-server e2e suite.
packages/json-crdt-repo/src/tests/e2e/json-crdt-server/clients.spec.ts	Add local server e2e suite for persistent/fetch clients across codecs.
packages/json-crdt-repo/src/tests/e2e/demo-client.ts	Add demo-server client setups for e2e.
packages/json-crdt-repo/src/tests/e2e/codecs.ts	Add codec matrix builders used by e2e.
packages/json-crdt-repo/src/tests/e2e/clients.ts	Add local server client setups for e2e.
packages/json-crdt-repo/src/demos/ui-text/webpack.config.js	Add demo build config for collaborative text UI demo.
packages/json-crdt-repo/src/demos/ui-text/main.tsx	Add collaborative textarea demo using `JsonCrdtRepo`.
packages/json-crdt-repo/src/demos/ui-json/webpack.config.js	Add demo build config for collaborative JSON UI demo.
packages/json-crdt-repo/src/demos/ui-json/main.tsx	Add interactive JSON demo using `JsonCrdtRepo`.
packages/json-crdt-repo/src/JsonCrdtRepo.ts	Implement browser repo wrapper (BrowserLevel + BroadcastChannel + remote history + sessions).
packages/json-crdt-repo/package.json	Add package manifest including deps, peerDeps, scripts, Jest config.
packages/json-crdt-repo/SECURITY.md	Add package security policy doc.
packages/json-crdt-repo/README.md	Add package-level README and basic usage snippet.
packages/json-crdt-repo/LICENSE	Add Apache-2.0 license text to package.
packages/collaborative-slate/src/tests/SlateFacade.undo.spec.ts	Ensure facade is disposed during Symbol.dispose cleanup.
packages/collaborative-slate/src/tests/SlateFacade.set.spec.ts	Ensure facade is disposed during Symbol.dispose cleanup.
packages/collaborative-slate/src/tests/SlateFacade.selection.spec.ts	Ensure facade is disposed during Symbol.dispose cleanup.
packages/collaborative-react/src/tests/setup.ts	Add RTL cleanup afterEach in collaborative-react tests.
packages/collaborative-react/package.json	Configure Jest setupFilesAfterEnv for collaborative-react.
packages/collaborative-prosemirror/src/tests/setupAfterEnv.ts	Add afterEach cleanup hook for active testbeds + DOM reset.
packages/collaborative-prosemirror/src/tests/setup.ts	Track and cleanup active testbeds; make DOM cleanup more robust.
packages/collaborative-prosemirror/src/tests/ProseMirrorFacade.selection.spec.ts	Use `using` to ensure deterministic testbed disposal.
packages/collaborative-prosemirror/package.json	Configure Jest setupFilesAfterEnv for collaborative-prosemirror.
packages/channel/src/tests/WebSocketChannel.spec.ts	Track and close active channels afterEach to prevent leaks/flakes.
packages/channel/src/tests/PersistentPhysicalChannel.spec.ts	Track and stop active persistents afterEach to prevent leaks/flakes.
packages/channel/src/PersistentPhysicalChannel.ts	Replace reconnect delays with cancellable `wait()` observable + timer unref.
package.json	Update root Jest invocation to run in-band (and add localstorage file path).
README.md	Reformat integrations list + add JSON CRDT Explorer link.
.gitignore	Ignore `/.tmp` directory used by tests.

Copilot · 2026-04-15T17:43:20Z

+export const shareByKey = <TValue>(sub: (key: string) => Observable<TValue>): ((key: string) => Observable<TValue>) => {
+  const map: Record<string, Observable<TValue>> = {};
+  return (key: string) => {


Using a plain object (Record<string, ...> = {}) as a cache keyed by arbitrary strings can be vulnerable to prototype-pollution edge cases (e.g. key __proto__) and can also collide with inherited properties. Prefer a Map<string, Observable<TValue>>, or initialize with Object.create(null) and access via Object.prototype.hasOwnProperty.call(...).

Copilot · 2026-04-15T17:43:20Z

+const timeout2 = <T>(ms: number, promise: Promise<T>): Promise<T | undefined> =>
+  timeout(ms, promise).catch(() => undefined);


timeout2() currently converts any rejection from timeout(ms, promise) into undefined, so an undo()/redo() implementation that rejects will be treated the same as a timeout (-2). If you need to distinguish timeout vs real errors, only swallow the specific timeout error and let other rejections propagate (or map them to -3 consistently).

Copilot · 2026-04-15T17:43:21Z

+  /** Thew new block schema, if any. */
+  schema?: NodeBuilder;


Typo in doc comment: "Thew new block schema" should be "The new block schema".

Copilot · 2026-04-15T17:43:21Z

+  /** Thew new block schema, if any. */
+  schema?: NodeBuilder;
+


EditSessionLoadOpts declares a schema?: NodeBuilder field, but load() never reads or applies it. This is confusing for callers and can lead to silent misconfiguration. Either remove the option, or if it's intended, apply it to the loaded session's model (similar to make()).

Copilot · 2026-04-15T17:43:21Z

+ * a centra server; (2) un-fetched content addressable storage files; or (3) a
+ * peer-to-peer network.


Typo in doc comment: "centra server" should be "central server".

Copilot · 2026-04-15T17:43:21Z

+        const cursorBehind = this.cursor !== res.cursor;
+        if (cursorBehind) {
+          const timer = setTimeout(async () => {
+            if (this._stopped) return;


this.cursor is compared to res.cursor but never updated on successful repo.sync(). This can keep the session thinking it's behind and trigger unnecessary getIf polling / missed cursor progression. Assign this.cursor = res.cursor (ideally immediately after repo.sync() succeeds) before using it for comparisons.

Copilot · 2026-04-15T17:43:22Z

+      this.sync()
+        .then((error) => {
+          this.onsyncerror?.(error);
+        })
+        .catch((error) => {
+          this.onsyncerror?.(error);
+        });


In syncLog(), the .then((error) => ...) branch calls onsyncerror with the successful return value of sync() (e.g. null or {remote}), not an error. This makes onsyncerror fire on success and can mask real failures. Only invoke onsyncerror from the .catch(...) path (or rename + add a separate success callback).

Copilot · 2026-04-15T17:43:22Z

+  public readSid(): number {
+    const ls = window.localStorage;
+    const key = this.opts.name + '-sid';


readSid() directly uses window.localStorage, which will throw in non-browser contexts (SSR, Node-based tooling/tests) even though this package is built under Node. Consider guarding with typeof window !== 'undefined' / globalThis.localStorage checks and/or allowing sid to be injected via constructor options for non-browser usage.

Copilot · 2026-04-15T17:43:22Z

+   * Weather to asynchronously pull for any existing local block state, if a
+   * block with the same ID already exists. Defaults to `true`.
+   */


Typo in doc comment: "Weather to asynchronously pull" should be "Whether to asynchronously pull".

streamich added 12 commits April 14, 2026 15:39

docs: add explorer site to README

0eb0170

chore: setup JSON CRDT Repo package

43ce09f

feat: implement cross-tab pubsub module

a52bb6e

feat: implement remote server client

3e46508

feat: 🎸 implement local CRDT state store and sync layer

548464e

feat: 🎸 add runtime "session" wrapper

df8d648

test: 💍 add tests and demos

2572d05

fix: 🐛 harden repo implementation

632f18b

feat: 🎸 improve event emission sequences

9821ddf

test: harden flaky tests

f2d0fa7

fix: verify array children exist on iteration

a89fbfa

style: fix linter issues

b752de9

Copilot AI review requested due to automatic review settings April 15, 2026 17:38

Copilot started reviewing on behalf of streamich April 15, 2026 17:38 View session

Copilot AI reviewed Apr 15, 2026

View reviewed changes

streamich added 3 commits April 15, 2026 20:04

test: revert test command to previous

4318133

fix: correctly import monorepo packages

2dfef93

test: increase test timeout

a4c5a71

streamich merged commit ad997fd into master Apr 15, 2026
9 checks passed

streamich deleted the json-crdt-repo branch April 15, 2026 18:27

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JSON CRDT Repo#1018

JSON CRDT Repo#1018
streamich merged 15 commits intomasterfrom
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		const timeout2 = <T>(ms: number, promise: Promise<T>): Promise<T \| undefined> =>
		timeout(ms, promise).catch(() => undefined);

		* a centra server; (2) un-fetched content addressable storage files; or (3) a
		* peer-to-peer network.

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