chore: fix peer discovery peer-exchange (#1069)

* fix: discovery for peer-exchange

use the bootstrap node as a starter to send a
peer-exchange query to, and emit the response
peers received from it for further connection to
libp2p using the peer-discovery interface

* init: test for libp2p bootstrap/discovery for
peer-exchange

* temp-add: console.logs for easier debugging

* add: peer discovery test & rm: console.logs

* chore: rm  and redundant spec test

* add: interval for peer exchange queries
we set an interval to query a peer every 5 minutes
for peer exchange, and add new peers if found

* address: reviews
- add `type` for imports not using values
- better handling for peer-exchange query interval

* chore: fix tsc for peer-exchange
use node16 for module resolution

* chore: add extra exports to fix typedoc warnings
ref: https://github.com/TypeStrong/typedoc/issues/1739

packages/interfaces/src/peer_exchange.ts

@@ -1,4 +1,5 @@
 import type { ConnectionManager } from "@libp2p/interface-connection-manager";
+import type { PeerId } from "@libp2p/interface-peer-id";
 import type { PeerStore } from "@libp2p/interface-peer-store";
 import type { Registrar } from "@libp2p/interface-registrar";
 
@@ -14,6 +15,7 @@ export interface IPeerExchange extends PointToPointProtocol {
 
 export interface PeerExchangeQueryParams {
   numPeers: number;
+  peerId?: PeerId;
 }
 
 export interface PeerExchangeResponse {

packages/peer-exchange/src/index.ts

@@ -1 +1,10 @@
-export * from "./waku_peer_exchange.js";
+export {
+  wakuPeerExchange,
+  PeerExchangeCodec,
+  WakuPeerExchange,
+} from "./waku_peer_exchange.js";
+export {
+  wakuPeerExchangeDiscovery,
+  PeerExchangeDiscovery,
+  Options,
+} from "./waku_peer_exchange_discovery.js";

packages/peer-exchange/src/waku_peer_exchange.ts

@@ -26,11 +26,18 @@ export const PeerExchangeCodec = "/vac/waku/peer-exchange/2.0.0-alpha1";
 
 const log = debug("waku:peer-exchange");
 
+/**
+ * Implementation of the Peer Exchange protocol (https://rfc.vac.dev/spec/34/)
+ */
 export class WakuPeerExchange implements IPeerExchange {
   private callback:
     | ((response: PeerExchangeResponse) => Promise<void>)
     | undefined;
 
+  /**
+   * @param components - libp2p components
+   * @param createOptions - Options for the protocol
+   */
   constructor(
     public components: PeerExchangeComponents,
     public createOptions?: ProtocolOptions
@@ -40,6 +47,9 @@ export class WakuPeerExchange implements IPeerExchange {
       .catch((e) => log("Failed to register peer exchange protocol", e));
   }
 
+  /**
+   * Make a peer exchange query to a peer
+   */
   async query(
     params: PeerExchangeQueryParams,
     callback: (response: PeerExchangeResponse) => Promise<void>
@@ -52,7 +62,7 @@ export class WakuPeerExchange implements IPeerExchange {
       numPeers: BigInt(numPeers),
     });
 
-    const peer = await this.getPeer();
+    const peer = await this.getPeer(params.peerId);
 
     const stream = await this.newStream(peer);
 
@@ -65,6 +75,9 @@ export class WakuPeerExchange implements IPeerExchange {
     );
   }
 
+  /**
+   * Handle a peer exchange query response
+   */
   private handler(streamData: IncomingStreamData): void {
     const { stream } = streamData;
     pipe(stream, lp.decode(), async (source) => {
@@ -94,6 +107,11 @@ export class WakuPeerExchange implements IPeerExchange {
     }).catch((err) => log("Failed to handle peer exchange request", err));
   }
 
+  /**
+   *
+   * @param peerId - Optional peer ID to select a peer
+   * @returns A peer to query
+   */
   private async getPeer(peerId?: PeerId): Promise<Peer> {
     const res = await selectPeerForProtocol(
       this.components.peerStore,
@@ -106,6 +124,10 @@ export class WakuPeerExchange implements IPeerExchange {
     return res.peer;
   }
 
+  /**
+   * @param peer - Peer to open a stream with
+   * @returns A new stream
+   */
   private async newStream(peer: Peer): Promise<Stream> {
     const connections = this.components.connectionManager.getConnections(
       peer.id
@@ -118,15 +140,26 @@ export class WakuPeerExchange implements IPeerExchange {
     return connection.newStream(PeerExchangeCodec);
   }
 
+  /**
+   * @returns All peers that support the peer exchange protocol
+   */
   async peers(): Promise<Peer[]> {
     return getPeersForProtocol(this.components.peerStore, [PeerExchangeCodec]);
   }
 
+  /**
+   * @returns The libp2p peer store
+   */
   get peerStore(): PeerStore {
     return this.components.peerStore;
   }
 }
 
+/**
+ *
+ * @param init - Options for the protocol
+ * @returns A function that creates a new peer exchange protocol
+ */
 export function wakuPeerExchange(
   init: Partial<ProtocolOptions> = {}
 ): (components: PeerExchangeComponents) => WakuPeerExchange {

packages/peer-exchange/src/waku_peer_exchange_discovery.ts

@@ -3,17 +3,21 @@ import {
   PeerDiscoveryEvents,
   symbol,
 } from "@libp2p/interface-peer-discovery";
+import type { PeerId } from "@libp2p/interface-peer-id";
 import { PeerInfo } from "@libp2p/interface-peer-info";
 import { PeerProtocolsChangeData } from "@libp2p/interface-peer-store";
 import { EventEmitter } from "@libp2p/interfaces/events";
 import { PeerExchangeComponents } from "@waku/interfaces";
 import debug from "debug";
 
-import { PeerExchangeCodec } from "./waku_peer_exchange";
+import { PeerExchangeCodec, WakuPeerExchange } from "./waku_peer_exchange.js";
 
 const log = debug("waku:peer-exchange-discovery");
 
-interface Options {
+const DEFAULT_PEER_EXCHANGE_REQUEST_NODES = 10;
+const PEER_EXCHANGE_QUERY_INTERVAL = 5 * 60 * 1000;
+
+export interface Options {
   /**
    * Tag a bootstrap peer with this name before "discovering" it (default: 'bootstrap')
    */
@@ -39,36 +43,82 @@ export class PeerExchangeDiscovery
   implements PeerDiscovery
 {
   private readonly components: PeerExchangeComponents;
+  private readonly peerExchange: WakuPeerExchange;
   private readonly options: Options;
   private isStarted: boolean;
+  private intervals: Map<PeerId, NodeJS.Timeout> = new Map();
 
   private readonly eventHandler = async (
     event: CustomEvent<PeerProtocolsChangeData>
   ): Promise<void> => {
-    const { protocols } = event.detail;
-    if (!protocols.includes(PeerExchangeCodec)) return;
+    const { protocols, peerId } = event.detail;
+    if (!protocols.includes(PeerExchangeCodec) || this.intervals.get(peerId))
+      return;
 
-    const { peerId } = event.detail;
-    const peer = await this.components.peerStore.get(peerId);
-    const peerInfo = {
-      id: peerId,
-      multiaddrs: peer.addresses.map((address) => address.multiaddr),
-      protocols: [],
-    };
-    await this.components.peerStore.tagPeer(
-      peerId,
-      DEFAULT_BOOTSTRAP_TAG_NAME,
-      {
-        value: this.options.tagValue ?? DEFAULT_BOOTSTRAP_TAG_VALUE,
-        ttl: this.options.tagTTL ?? DEFAULT_BOOTSTRAP_TAG_TTL,
-      }
-    );
-    this.dispatchEvent(new CustomEvent<PeerInfo>("peer", { detail: peerInfo }));
+    const interval = setInterval(async () => {
+      await this.peerExchange.query(
+        {
+          numPeers: DEFAULT_PEER_EXCHANGE_REQUEST_NODES,
+          peerId,
+        },
+        async (response) => {
+          const { peerInfos } = response;
+
+          for (const _peerInfo of peerInfos) {
+            const { ENR } = _peerInfo;
+            if (!ENR) {
+              log("no ENR");
+              continue;
+            }
+
+            const { peerId, multiaddrs } = ENR;
+
+            if (!peerId) {
+              log("no peerId");
+              continue;
+            }
+            if (!multiaddrs || multiaddrs.length === 0) {
+              log("no multiaddrs");
+              continue;
+            }
+
+            // check if peer is already in peerStore
+            const existingPeer = await this.components.peerStore.get(peerId);
+            if (existingPeer) {
+              log("peer already in peerStore");
+              continue;
+            }
+
+            await this.components.peerStore.tagPeer(
+              peerId,
+              DEFAULT_BOOTSTRAP_TAG_NAME,
+              {
+                value: this.options.tagValue ?? DEFAULT_BOOTSTRAP_TAG_VALUE,
+                ttl: this.options.tagTTL ?? DEFAULT_BOOTSTRAP_TAG_TTL,
+              }
+            );
+
+            this.dispatchEvent(
+              new CustomEvent<PeerInfo>("peer", {
+                detail: {
+                  id: peerId,
+                  multiaddrs,
+                  protocols: [],
+                },
+              })
+            );
+          }
+        }
+      );
+    }, PEER_EXCHANGE_QUERY_INTERVAL);
+
+    this.intervals.set(peerId, interval);
   };
 
   constructor(components: PeerExchangeComponents, options: Options = {}) {
     super();
     this.components = components;
+    this.peerExchange = new WakuPeerExchange(components);
     this.options = options;
     this.isStarted = false;
   }
@@ -96,6 +146,7 @@ export class PeerExchangeDiscovery
     if (!this.isStarted) return;
     log("Stopping peer exchange node discovery");
     this.isStarted = false;
+    this.intervals.forEach((interval) => clearInterval(interval));
     this.components.peerStore.removeEventListener(
       "change:protocols",
       this.eventHandler
@@ -110,3 +161,10 @@ export class PeerExchangeDiscovery
     return "@waku/peer-exchange";
   }
 }
+
+export function wakuPeerExchangeDiscovery(): (
+  components: PeerExchangeComponents
+) => PeerExchangeDiscovery {
+  return (components: PeerExchangeComponents) =>
+    new PeerExchangeDiscovery(components);
+}

packages/peer-exchange/tsconfig.json

@@ -1,54 +1,10 @@
 {
+  "extends": "../../tsconfig",
   "compilerOptions": {
-    "incremental": true,
-    "target": "es2020",
-    "outDir": "dist",
+    "outDir": "dist/",
     "rootDir": "src",
-    "moduleResolution": "node",
-    "module": "es2020",
-    "declaration": true,
-    "sourceMap": true,
-    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
-    "resolveJsonModule": true /* Include modules imported with .json extension. */,
-    "tsBuildInfoFile": "dist/.tsbuildinfo",
-    "strict": true /* Enable all strict type-checking options. */,
-
-    /* Strict Type-Checking Options */
-    "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
-    "strictNullChecks": true /* Enable strict null checks. */,
-    "strictFunctionTypes": true /* Enable strict checking of function types. */,
-    "strictPropertyInitialization": true /* Enable strict checking of property initialization in classes. */,
-    "noImplicitThis": true /* Raise error on 'this' expressions with an implied 'any' type. */,
-    "alwaysStrict": true /* Parse in strict mode and emit "use strict" for each source file. */,
-
-    /* Additional Checks */
-    "noUnusedLocals": true /* Report errors on unused locals. */,
-    "noUnusedParameters": true /* Report errors on unused parameters. */,
-    "noImplicitReturns": true /* Report error when not all code paths in function return a value. */,
-    "noFallthroughCasesInSwitch": true /* Report errors for fallthrough cases in switch statement. */,
-    "forceConsistentCasingInFileNames": true,
-
-    /* Debugging Options */
-    "traceResolution": false /* Report module resolution log messages. */,
-    "listEmittedFiles": false /* Print names of generated files part of the compilation. */,
-    "listFiles": false /* Print names of files part of the compilation. */,
-    "pretty": true /* Stylize errors and messages using color and context. */,
-
-    // Due to broken types in indirect dependencies
-    "skipLibCheck": true,
-
-    /* Experimental Options */
-    // "experimentalDecorators": true /* Enables experimental support for ES7 decorators. */,
-    // "emitDecoratorMetadata": true /* Enables experimental support for emitting type metadata for decorators. */,
-
-    "lib": ["es2020", "dom"],
-    "types": ["node", "mocha"],
-    "typeRoots": ["node_modules/@types", "src/types"]
+    "tsBuildInfoFile": "dist/.tsbuildinfo"
   },
-  "include": ["src", ".eslintrc.js"],
-  "exclude": ["src/**/*.spec.ts", "src/test_utils", "dist", "bundle"],
-  "compileOnSave": false,
-  "ts-node": {
-    "files": true
-  }
+  "include": ["src"],
+  "exclude": ["src/**/*.spec.ts", "src/test_utils"]
 }

packages/tests/tests/peer_exchange.node.spec.ts

@@ -7,15 +7,38 @@ import {
 import { createLightNode } from "@waku/create";
 import type { LightNode, PeerExchangeResponse } from "@waku/interfaces";
 import { Protocols } from "@waku/interfaces";
+import { wakuPeerExchangeDiscovery } from "@waku/peer-exchange";
 import { expect } from "chai";
 
-describe("Peer Exchange: Node", () => {
+import { delay } from "../src/delay.js";
+
+describe("Peer Exchange", () => {
   let waku: LightNode;
   afterEach(async function () {
     !!waku && waku.stop().catch((e) => console.log("Waku failed to stop", e));
   });
 
-  it("Test Fleet: Queries successfully [Live Data]", async function () {
+  it("Auto discovery", async function () {
+    this.timeout(120_000);
+
+    waku = await createLightNode({
+      libp2p: {
+        peerDiscovery: [
+          bootstrap({ list: getPredefinedBootstrapNodes(Fleet.Test) }),
+          wakuPeerExchangeDiscovery(),
+        ],
+      },
+    });
+
+    await waku.start();
+    await delay(1000);
+
+    await waitForRemotePeer(waku, [Protocols.PeerExchange]);
+    const pxPeers = await waku.peerExchange.peers();
+    expect(pxPeers.length).to.be.greaterThan(0);
+  });
+
+  it("Manual query on test fleet", async function () {
     this.timeout(150_000);
 
     // skipping in CI as this test demonstrates Peer Exchange working with the test fleet