RedditBot/tests/chat-service-cooldown.test.ts

import { describe, it, expect } from 'vitest';
import { ChatService } from '../src/services/chat/service.js';
import { MatrixClient, MatrixRateLimitError } from '../src/services/chat/matrix/client.js';
import { createMockLogger } from './mockLogger.js';

const creds = {
  homeserver: 'https://matrix.example.test',
  accessToken: 'tok',
  userId: '@me:example.test',
  capturedAt: Date.now(),
};

function buildService() {
  const logger = createMockLogger();
  // Fetch impl never matters here — we drive cooldowns directly via the
  // public API, which is how MatrixClient surfaces them at runtime.
  const fetchImpl = (() =>
    Promise.resolve(
      new Response('{}', { status: 200, headers: { 'content-type': 'application/json' } }),
    )) as typeof fetch;
  const matrix = new MatrixClient(creds, logger, { minRequestIntervalMs: 0, fetchImpl });
  const svc = new ChatService(matrix, logger);
  return { svc, logger };
}

describe('ChatService invitation cooldown', () => {
  it('is null by default', () => {
    const { svc } = buildService();
    expect(svc.getInvitationCooldown()).toBeNull();
  });

  it('records a cooldown from a MatrixRateLimitError', () => {
    const { svc } = buildService();
    const err = new MatrixRateLimitError(
      '429',
      60_000,
      'M_LIMIT_EXCEEDED',
      'rate.invitation_limit_mature_account',
    );
    svc.setInvitationCooldown(err);
    const active = svc.getInvitationCooldown();
    expect(active).not.toBeNull();
    expect(active!.redditCode).toBe('rate.invitation_limit_mature_account');
    expect(active!.until).toBeGreaterThan(Date.now() + 50_000);
    expect(active!.reason).toMatch(/throttling new chat invitations/);
  });

  it('auto-expires once the until timestamp has passed', () => {
    const { svc } = buildService();
    const err = new MatrixRateLimitError('429', 10, 'M_LIMIT_EXCEEDED', 'rate.foo');
    svc.setInvitationCooldown(err);
    expect(svc.getInvitationCooldown()).not.toBeNull();

    // Force the clock past the cooldown window.
    const cooldown = svc.getInvitationCooldown()!;
    const realNow = Date.now;
    Date.now = () => cooldown.until + 1;
    try {
      expect(svc.getInvitationCooldown()).toBeNull();
    } finally {
      Date.now = realNow;
    }
  });

  it('startConversation short-circuits when a cooldown is active', async () => {
    const { svc } = buildService();
    svc.setInvitationCooldown(
      new MatrixRateLimitError('429', 60_000, 'M_LIMIT_EXCEEDED', 'rate.foo'),
    );
    const result = await svc.startConversation('someuser', 'hi');
    expect(result).toBeNull();
  });

  it('sendChatMessage short-circuits when a cooldown is active', async () => {
    const { svc } = buildService();
    svc.setInvitationCooldown(
      new MatrixRateLimitError('429', 60_000, 'M_LIMIT_EXCEEDED', null),
    );
    const result = await svc.sendChatMessage('!room:example.test', 'hi');
    expect(result).toBe(false);
  });

  it('sendChatMessage records a cooldown when the homeserver rate-limits a reply', async () => {
    const logger = createMockLogger();
    const matrix = new MatrixClient(creds, logger, { minRequestIntervalMs: 0 });
    // Force sendTextMessage to throw a rate-limit error — simulates Reddit
    // returning M_LIMIT_EXCEEDED on a reply into an existing room.
    matrix.sendTextMessage = async () => {
      throw new MatrixRateLimitError('429', 90_000, 'M_LIMIT_EXCEEDED', null);
    };
    const svc = new ChatService(matrix, logger);

    const result = await svc.sendChatMessage('!room:example.test', 'hi');
    expect(result).toBe(false);
    const active = svc.getInvitationCooldown();
    expect(active).not.toBeNull();
    expect(active!.until).toBeGreaterThan(Date.now() + 80_000);
  });
});