broadcaster.test.ts

import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import { appendEvent, __resetActivityEventLog } from './log';
import { broadcast, subscribe } from './broadcaster';
import type { ActivityEvent } from './types';

beforeEach(() => {
  __resetActivityEventLog();
});

afterEach(() => {
  vi.restoreAllMocks();
});

describe('broadcaster', () => {
  it('delivers manually broadcast events to subscribers', () => {
    const handler = vi.fn();
    const unsubscribe = subscribe(handler);

    const event: ActivityEvent = {
      seq: 99,
      at: '2026-01-01T00:00:00.000Z',
      kind: 'partner_webhook_received',
      actor: { kind: 'partner', slug: 'demo' },
      offer_id: 'offer-1',
      event_name: 'attribution_verified',
      idempotency_key: 'key-1',
    };

    broadcast(event);
    expect(handler).toHaveBeenCalledTimes(1);
    expect(handler.mock.calls[0][0]).toEqual(event);

    unsubscribe();
  });

  it('stops delivering to unsubscribed handlers', () => {
    const handler = vi.fn();
    const unsubscribe = subscribe(handler);
    unsubscribe();

    broadcast({
      seq: 1,
      at: '2026-01-01T00:00:00.000Z',
      kind: 'offer_deleted',
      actor: { kind: 'system' },
      offer_id: 'x',
    });

    expect(handler).not.toHaveBeenCalled();
  });

  it('fans out appendEvent calls through the broadcaster', () => {
    const handler = vi.fn();
    const unsubscribe = subscribe(handler);

    appendEvent({
      kind: 'offer_deleted',
      actor: { kind: 'system' },
      offer_id: 'o-fanout',
    });

    expect(handler).toHaveBeenCalledTimes(1);
    const received = handler.mock.calls[0][0] as ActivityEvent;
    expect(received.kind).toBe('offer_deleted');
    expect(received.offer_id).toBe('o-fanout');
    expect(received.seq).toBe(1);

    unsubscribe();
  });

  it('supports multiple concurrent subscribers', () => {
    const a = vi.fn();
    const b = vi.fn();
    const unsubA = subscribe(a);
    const unsubB = subscribe(b);

    appendEvent({
      kind: 'offer_deleted',
      actor: { kind: 'system' },
      offer_id: 'o-two',
    });

    expect(a).toHaveBeenCalledTimes(1);
    expect(b).toHaveBeenCalledTimes(1);

    unsubA();
    unsubB();
  });
});