<pre class="shiki github-dark shaku"><code>// This is a JavaScript coding problem from BFE.devinterface ISomePort { postMessage?: (message: string, callback?: (data: string) =&gt; void) =&gt; void onmessage?: (message: string, reply: (data: string) =&gt; void) =&gt; void onmessageHelper: (message: string, reply: (message: string) =&gt; void) =&gt; void isInvoked: { [k: string]: boolean; } isMessageInvoked: (message: string) =&gt; boolean}class SomePort implements ISomePort { isInvoked = {}; isMessageInvoked(message: string) { if (this.isInvoked[message]) { return true; } this.isInvoked[message] = true; return false; } onmessageHelper(message: string, callback: (data: string) =&gt; void) { if (this.isMessageInvoked(message)) { return; } callback(message); }}interface ISomeChannel { port1: ISomePort; port2: ISomePort;}class Channel implements ISomeChannel { port1: ISomePort; port2: ISomePort; constructor() { this.port1 = new SomePort(); this.port2 = new SomePort(); this.createPortConnection(this.port1, this.port2); this.createPortConnection(this.port2, this.port1); } createPortConnection(port1: ISomePort, port2: ISomePort) { port1.postMessage = (message, callback) =&gt; { if (port2.onmessage) { port2.onmessage(message, function (data: string) { port2.onmessageHelper(data, callback); }); } } }}class BetterChannel { port1: ISomePort; port2: ISomePort; constructor() { const {port1, port2} = new Channel(); this.port1 = port1; this.port2 = port2; }}const {port1, port2} = new BetterChannel();// port1.postMessage('1?', (d) =&gt; {// console.log(d)// })</code></pre>

It's okay I guess

We have SomeChannel which allows us to send messages between 2 ports. const {port1, port2} = new SomeChannel()port2.onmessage = (message) => { console…