Add tests where js initialize the connection to nim

src/lib/waku.ts

@@ -3,8 +3,10 @@ import Mplex from 'libp2p-mplex';
 import { bytes } from 'libp2p-noise/dist/src/@types/basic';
 import { Noise } from 'libp2p-noise/dist/src/noise';
 import TCP from 'libp2p-tcp';
+import Multiaddr from 'multiaddr';
+import PeerId from 'peer-id';
 
-import { WakuRelay, WakuRelayPubsub } from './waku_relay';
+import { CODEC, WakuRelay, WakuRelayPubsub } from './waku_relay';
 
 export default class Waku {
   private constructor(public libp2p: Libp2p, public relay: WakuRelay) {}
@@ -35,6 +37,11 @@ export default class Waku {
     return new Waku(libp2p, new WakuRelay(libp2p.pubsub));
   }
 
+  async dialWithMultiAddr(peerId: PeerId, multiaddr: Multiaddr[]) {
+    this.libp2p.peerStore.addressBook.set(peerId, multiaddr);
+    return this.libp2p.dialProtocol(peerId, CODEC);
+  }
+
   async stop() {
     await this.libp2p.stop();
   }

src/lib/waku_relay.spec.ts

@@ -65,6 +65,7 @@ describe('Waku Relay', () => {
   });
 
   describe('Interop: Nim', function () {
+    describe('Nim connects to js', function () {
       let waku: Waku;
       let nimWaku: NimWaku;
 
@@ -140,6 +141,74 @@ describe('Waku Relay', () => {
         expect(Buffer.compare(payload, message.payload!)).to.eq(0);
       });
     });
+
+    describe('Js connects to nim', function () {
+      let waku: Waku;
+      let nimWaku: NimWaku;
+
+      beforeEach(async function () {
+        this.timeout(10_000);
+        waku = await Waku.create(NOISE_KEY_1);
+
+        nimWaku = new NimWaku(makeLogFileName(this));
+        await nimWaku.start();
+
+        const nimPeerId = await nimWaku.getPeerId();
+
+        await waku.dialWithMultiAddr(nimPeerId, [nimWaku.multiaddr]);
+
+        await waku.relay.subscribe();
+
+        await new Promise((resolve) =>
+          waku.libp2p.pubsub.once('gossipsub:heartbeat', resolve)
+        );
+      });
+
+      afterEach(async function () {
+        nimWaku ? nimWaku.stop() : null;
+        waku ? await waku.stop() : null;
+      });
+
+      it('nim subscribes to js', async function () {
+        const subscribers = waku.libp2p.pubsub.getSubscribers(TOPIC);
+
+        const nimPeerId = await nimWaku.getPeerId();
+        expect(subscribers).to.contain(nimPeerId.toB58String());
+      });
+
+      it('Js publishes to nim', async function () {
+        const message = Message.fromUtf8String('This is a message');
+
+        await waku.relay.publish(message);
+
+        await nimWaku.waitForLog('WakuMessage received');
+
+        const msgs = await nimWaku.messages();
+
+        expect(msgs[0].contentTopic).to.equal(message.contentTopic);
+        expect(msgs[0].version).to.equal(message.version);
+
+        const payload = Buffer.from(msgs[0].payload);
+        expect(Buffer.compare(payload, message.payload!)).to.equal(0);
+      });
+
+      it('Nim publishes to js', async function () {
+        const message = Message.fromUtf8String('Here is another message.');
+
+        const receivedPromise = waitForNextData(waku.libp2p.pubsub);
+
+        await nimWaku.sendMessage(message);
+
+        const receivedMsg = await receivedPromise;
+
+        expect(receivedMsg.contentTopic).to.eq(message.contentTopic);
+        expect(receivedMsg.version).to.eq(message.version);
+
+        const payload = Buffer.from(receivedMsg.payload!);
+        expect(Buffer.compare(payload, message.payload!)).to.eq(0);
+      });
+    });
+  });
 });
 
 function waitForNextData(pubsub: Pubsub): Promise<Message> {

src/test_utils/nim_waku.ts

@@ -42,7 +42,7 @@ export class NimWaku {
     this.logPath = `${LOG_DIR}/nim-waku_${logName}.log`;
   }
 
-  async start(args: Args) {
+  async start(args?: Args) {
     try {
       await existsAsync(LOG_DIR);
     } catch (e) {