Testing

Everything in the library runs in memory against a real SQLite engine, so sync behaviour can be tested with ordinary unit tests: no browser, no server.

MemoryAdapter: an in-memory SQLite database. Works in Node.
FakeTransport: a scripted server that follows the server protocol.

import { describe, it, expect } from 'vitest';
import { Database, MemoryAdapter, FakeTransport, createSyncRuntime } from 'declarative-sqlite';
import { appSchema } from '../src/schema';

describe('task sync', () => {
  it('keeps the user edit when another device changes the same row', async () => {
    const db = await Database.open({ schema: appSchema, adapter: new MemoryAdapter() });
    const server = new FakeTransport();
    server.seed('TASK', [{ id: 'A', data: { PROJECT_ID: 42, TITLE: 'Pump', HOURS: 1 } }]);

    const sync = await createSyncRuntime({ db, transport: server, deviceId: 'test', debounceMs: 0 });
    await sync.pull.pull('task', { project_id: 42 });

    await sync.outbox.record({ table: 'task', systemId: 'A', changes: { hours: 5 } });
    server.serverEdit('TASK', 'A', { TITLE: 'Pump (renamed)' });
    await sync.pull.pull('task', { project_id: 42 });

    const row = await db.tables.task.get('A');
    expect(row).toMatchObject({ hours: 5, title: 'Pump (renamed)' });

    await sync.push.pushNow();
    expect(await sync.outbox.counts()).toMatchObject({ pending: 0, rejected: 0 });

    sync.close();
    await db.close();
  });
});

Table and column names passed to FakeTransport are the uppercase wire names.

FakeTransport

Method	Simulates
`seed(table, rows)`	Rows that already exist on the server. Each gets the next `seq`
`serverEdit(table, id, data)`	Another device changing a row
`tombstone(table, id)`	A row deleted on the server
`reject(table, column, error)`	The server refusing every change to that column
`failNextPush(error?)`	A network failure on the next push
`pushes`, `pulls`	Every batch and request received, for assertions

new FakeTransport({ pageSize: 2 }) forces small pages to test paging.

It behaves like a real server: changes apply in order with the last one winning, replaying a batchId returns the stored answer, and a change to a missing or deleted row is rejected.

Tips

Set debounceMs: 0 or call sync.push.pushNow() so tests don't wait for the push timer.
Pass clock to createSyncRuntime for deterministic timestamps.
Close the runtime and the database at the end of each test.

FakeTransport​

Tips​

FakeTransport

Tips