@schemeless/event-store-adapter-watermelondb

WatermelonDB-powered persistence layer for @schemeless/event-store-react-native. It stores every emitted event inside a high-performance SQLite database so that React Native applications can replay and synchronise their domain history offline.

Installation

yarn add @schemeless/event-store-adapter-watermelondb

This package expects WatermelonDB, React and React Native to be provided by the host application. Make sure they are already listed in your project dependencies:

yarn add @nozbe/watermelondb react react-native

Schema

The adapter exposes an eventStoreSchema helper that you can compose into your WatermelonDB database schema:

import { appSchema, Database } from '@nozbe/watermelondb';
import SQLiteAdapter from '@nozbe/watermelondb/adapters/sqlite';
import { eventStoreSchema } from '@schemeless/event-store-adapter-watermelondb';

const schema = appSchema({
  version: 1,
  tables: [eventStoreSchema],
});

const adapter = new SQLiteAdapter({ schema });
const database = new Database({ adapter, modelClasses: [] });

If you already have an application schema, simply append eventStoreSchema to your existing table list. The schema declares an events table with the following columns:

• domain: string – the bounded context that emitted the event.
• type: string – the event type within the domain.
• payload: stringified JSON payload.
• meta: optional stringified JSON metadata.
• identifier: optional aggregate identifier.
• correlation_id: optional correlation identifier.
• causation_id: optional causation identifier.
• created: numeric timestamp (milliseconds since epoch).

Usage

import { appSchema, Database } from '@nozbe/watermelondb';
import SQLiteAdapter from '@nozbe/watermelondb/adapters/sqlite';
import { makeEventStore } from '@schemeless/event-store-react-native';
import { EventStoreRepo, eventStoreSchema } from '@schemeless/event-store-adapter-watermelondb';
import { eventFlows } from './eventFlows';

const schema = appSchema({
  version: 1,
  tables: [eventStoreSchema],
});

const adapter = new SQLiteAdapter({ schema });
const database = new Database({
  adapter,
  modelClasses: [],
});

const repo = new EventStoreRepo(database);
await repo.init(); // no-op but kept for interface symmetry

const eventStore = await makeEventStore(repo)(eventFlows);

await eventStore.receive(eventFlows.userRegistered)({
  payload: { id: 'user-123', email: '[email protected]' },
});

EventStoreRepo#getAllEvents returns an async iterator that yields events ordered by creation time. This makes it easy to replay batches or sync them with a remote backend without loading the full dataset into memory.

Resetting the store

Call await repo.resetStore() if you ever need to purge all locally stored events—for example during a user logout.