Toju/e2e/helpers/peer-role.ts

import { expect, type Page } from '@playwright/test';

export interface PeerRoleEdge {
  /** Remote peer id, in the identity space of the signal server routing that peer. */
  peerId: string;
  /** Our own actor id in that same identity space. */
  localActorId: string | null;
  isInitiator: boolean;
  connectionState: string;
}

/**
 * Read who elected themselves initiator for every active peer, together with the local
 * actor id in that peer's identity space. Both halves of a pair must describe the same
 * two ids, which is what makes the election comparable in the first place.
 */
export async function readPeerRoleEdges(page: Page): Promise<PeerRoleEdge[]> {
  return await page.evaluate(() => {
    interface AngularDebugApi {
      getComponent: (element: Element) => Record<string, unknown>;
    }
    interface PeerDataShape {
      connection?: { connectionState?: string };
      isInitiator?: boolean;
    }
    interface RealtimeShape {
      peerManager?: { activePeerConnections?: Map<string, PeerDataShape> };
      signalingTransportHandler?: {
        getIdentifyCredentialsForPeer?: (peerId: string) => { oderId?: string } | null;
      };
    }

    const host = document.querySelector('app-rooms-side-panel');
    const debugApi = (window as { ng?: AngularDebugApi }).ng;

    if (!host || !debugApi?.getComponent) {
      return [];
    }

    const realtime = debugApi.getComponent(host)['realtime'] as RealtimeShape | undefined;
    const peers = realtime?.peerManager?.activePeerConnections;

    if (!peers) {
      return [];
    }

    const edges: PeerRoleEdge[] = [];

    peers.forEach((peerData, peerId) => {
      const credentials = realtime?.signalingTransportHandler?.getIdentifyCredentialsForPeer?.(peerId);

      edges.push({
        connectionState: peerData.connection?.connectionState ?? 'unknown',
        isInitiator: peerData.isInitiator === true,
        localActorId: credentials?.oderId ?? null,
        peerId
      });
    });

    return edges;
  });
}

/**
 * How many RTCPeerConnections this page has created since load. A clean session creates
 * exactly one per remote peer; a rebuilt peer - for example a non-initiator that gave up
 * waiting for an offer that was never elected to be sent - adds another.
 */
export async function countCreatedPeerConnections(page: Page): Promise<number> {
  return await page.evaluate(() =>
    ((window as unknown as { __rtcConnections?: RTCPeerConnection[] }).__rtcConnections ?? []).length
  );
}

/**
 * Every connected pair must have exactly one initiator. Comparing ids from two different
 * identity spaces breaks the antisymmetry of the election, so both peers offer (glare) or
 * neither does until a takeover timer fires.
 */
export function expectExactlyOneInitiatorPerPair(edgesByClient: Record<string, PeerRoleEdge[]>): void {
  const directed = new Map<string, boolean>();
  const pairs = new Set<string>();

  for (const [clientName, edges] of Object.entries(edgesByClient)) {
    for (const edge of edges) {
      expect(
        edge.localActorId,
        `${clientName} has no local actor id in the identity space of peer ${edge.peerId}`
      ).toBeTruthy();

      const localActorId = edge.localActorId as string;

      directed.set(`${localActorId}->${edge.peerId}`, edge.isInitiator);
      pairs.add([localActorId, edge.peerId].sort().join('<->'));
    }
  }

  expect(pairs.size, 'expected at least one peer pair').toBeGreaterThan(0);

  for (const pair of pairs) {
    const [first, second] = pair.split('<->');
    const forward = directed.get(`${first}->${second}`);
    const backward = directed.get(`${second}->${first}`);

    expect(forward, `missing peer connection ${first} -> ${second}`).not.toBeUndefined();
    expect(backward, `missing peer connection ${second} -> ${first}`).not.toBeUndefined();
    expect(
      [forward, backward].filter(Boolean),
      `expected exactly one initiator for pair ${pair}`
    ).toHaveLength(1);
  }
}