import { describe, it, expect, vi, beforeEach } from 'vitest';
import { LocalEventBus } from '../events/local-event-bus.js';
describe('LocalEventBus', () => {
let bus: LocalEventBus;
beforeEach(() => {
bus = new LocalEventBus();
});
const makeEvent = (id: string) => ({
type: 'task_changed' as const,
id,
tool: 'backlog_update',
actor: 'test',
ts: new Date().toISOString(),
});
it('should assign incrementing sequence numbers', () => {
const events: any[] = [];
bus.subscribe((e) => events.push(e));
bus.emit(makeEvent('TASK-0001'));
bus.emit(makeEvent('TASK-0002'));
expect(events).toHaveLength(2);
expect(events[0].seq).toBe(1);
expect(events[1].seq).toBe(2);
});
it('should notify all subscribers', () => {
const cb1 = vi.fn();
const cb2 = vi.fn();
bus.subscribe(cb1);
bus.subscribe(cb2);
bus.emit(makeEvent('TASK-0001'));
expect(cb1).toHaveBeenCalledOnce();
expect(cb2).toHaveBeenCalledOnce();
});
it('should stop notifying after unsubscribe', () => {
const cb = vi.fn();
bus.subscribe(cb);
bus.emit(makeEvent('TASK-0001'));
expect(cb).toHaveBeenCalledOnce();
bus.unsubscribe(cb);
bus.emit(makeEvent('TASK-0002'));
expect(cb).toHaveBeenCalledOnce(); // still 1
});
it('should replay events since a given sequence number', () => {
bus.emit(makeEvent('TASK-0001'));
bus.emit(makeEvent('TASK-0002'));
bus.emit(makeEvent('TASK-0003'));
const missed = bus.replaySince(1);
expect(missed).toHaveLength(2);
expect(missed[0].id).toBe('TASK-0002');
expect(missed[1].id).toBe('TASK-0003');
});
it('should return empty array when replaying from current seq', () => {
bus.emit(makeEvent('TASK-0001'));
expect(bus.replaySince(1)).toHaveLength(0);
});
it('should respect ring buffer size limit', () => {
// Emit more than buffer size (1000)
for (let i = 0; i < 1050; i++) {
bus.emit(makeEvent(`TASK-${i.toString().padStart(4, '0')}`));
}
// Replay from seq 0 should only return last 1000
const all = bus.replaySince(0);
expect(all).toHaveLength(1000);
expect(all[0].seq).toBe(51); // first 50 dropped
expect(all[999].seq).toBe(1050);
});
});
