cinny/src/app/plugins/call/CallWidgetDriver.rtcTransports.test.ts

import { test } from 'node:test';
import assert from 'node:assert/strict';
import type { MatrixClient } from 'matrix-js-sdk';
import { AutoDiscovery } from 'matrix-js-sdk';
import { CallWidgetDriver } from './CallWidgetDriver';

// MSC4515: Element Call (widget mode) asks the host for RTC transports. Without a
// working answer every call fails with MISSING_MATRIX_RTC_TRANSPORT.
function fakeClient(opts: {
  serverTransports?: unknown[] | Error;
  wellKnown?: Record<string, unknown>;
}): MatrixClient {
  return {
    getDeviceId: () => 'DEV',
    getSafeUserId: () => '@me:example.org',
    _unstable_getRTCTransports: async () => {
      if (opts.serverTransports instanceof Error) throw opts.serverTransports;
      return opts.serverTransports ?? [];
    },
    getClientWellKnown: () => opts.wellKnown,
    getDomain: () => 'example.org',
  } as unknown as MatrixClient;
}

const focus = { type: 'livekit', livekit_service_url: 'https://matrix.example.org' };

test('getRtcTransports prefers the homeserver MSC4143 endpoint', async () => {
  const driver = new CallWidgetDriver(fakeClient({ serverTransports: [focus] }), '!r:x');
  const r = await driver.getRtcTransports();
  assert.deepEqual(r.rtc_transports, [focus]);
});

test('getRtcTransports falls back to .well-known rtc_foci when the endpoint 404s', async () => {
  const driver = new CallWidgetDriver(
    fakeClient({
      serverTransports: new Error('404'),
      wellKnown: { 'org.matrix.msc4143.rtc_foci': [focus, { junk: true }, null] },
    }),
    '!r:x',
  );
  const r = await driver.getRtcTransports();
  assert.deepEqual(r.rtc_transports, [focus]);
});

test('getRtcTransports fetches .well-known itself when the SDK has nothing cached (the live cinny case)', async () => {
  // cinny never sets clientWellKnownPollPeriod, so getClientWellKnown() is undefined
  // at runtime; the driver must resolve it via AutoDiscovery instead.
  const orig = AutoDiscovery.getRawClientConfig;
  let calls = 0;
  AutoDiscovery.getRawClientConfig = async () => {
    calls += 1;
    return { 'org.matrix.msc4143.rtc_foci': [focus] } as never;
  };
  try {
    const driver = new CallWidgetDriver(
      fakeClient({ serverTransports: new Error('404'), wellKnown: undefined }),
      '!r:x',
    );
    const r1 = await driver.getRtcTransports();
    const r2 = await driver.getRtcTransports();
    assert.deepEqual(r1.rtc_transports, [focus]);
    assert.deepEqual(r2.rtc_transports, [focus]);
    assert.equal(calls, 1, 'well-known is fetched once per driver');
  } finally {
    AutoDiscovery.getRawClientConfig = orig;
  }
});

test('getRtcTransports returns an empty list when nothing is advertised', async () => {
  const orig = AutoDiscovery.getRawClientConfig;
  AutoDiscovery.getRawClientConfig = async () => ({ 'm.homeserver': {} }) as never;
  try {
    const driver = new CallWidgetDriver(
      fakeClient({ serverTransports: [], wellKnown: { 'm.homeserver': {} } }),
      '!r:x',
    );
    const r = await driver.getRtcTransports();
    assert.deepEqual(r.rtc_transports, []);
  } finally {
    AutoDiscovery.getRawClientConfig = orig;
  }
});

test('the MSC4515 capability is granted to the call widget', async () => {
  const driver = new CallWidgetDriver(fakeClient({}), '!r:x');
  const allowed = await driver.validateCapabilities(
    new Set(['org.matrix.msc4515.rtc_transports', 'org.example.not_allowed']),
  );
  assert.deepEqual(Array.from(allowed), ['org.matrix.msc4515.rtc_transports']);
});