Wrap nRepl client close in a promise

Poor (dumb) man's way to wait for `close` messages to have been sent
before destroying the socket.

* Fixes #2301

src/connector.ts

@@ -68,7 +68,7 @@ async function connectToHost(hostname: string, port: number, connectSequence: Re
 
   if (nClient) {
     nClient['silent'] = true;
-    nClient.close();
+    await nClient.close();
   }
 
   let cljSession: NReplSession;
@@ -863,7 +863,7 @@ export default {
       } else {
         // the connection may be ended before
         // the REPL client was connected.
-        nClient.close();
+        void nClient.close();
       }
       liveShareSupport.didDisconnectRepl();
       nClient = undefined;

src/nrepl/index.ts

@@ -111,14 +111,20 @@ export class NReplClient {
     log(data, Direction.ClientToServer);
   }
 
-  close() {
-    for (const id in this.sessions) {
-      this.sessions[id].close();
-    }
-    // TODO: Figure out a way to know when the socket can be destroyed without an error.
-    setTimeout(() => {
-      this.disconnect();
-    }, 1000);
+  async close() {
+    return new Promise<NReplClient>((resolve, _reject) => {
+      for (const id in this.sessions) {
+        this.sessions[id].close();
+      }
+      // TODO: We probably need to make the whole disconnect process awaitable
+      //       So that we do not destroy the socket before we have sent the `close` message
+      //       This setTimeout caused https://github.com/BetterThanTomorrow/calva/issues/2301
+      //       For now wrapped in a promise...
+      setTimeout(() => {
+        this.disconnect();
+        resolve(this);
+      }, 1000);
+    });
   }
 
   disconnect() {