✨ Introduce host chaining w/ 'chainedSession' method + remove old 'session' method

lib/ssh.js

@@ -22,22 +22,49 @@ module.exports = {
             password
         });
     }),
-    session: ({ address, port, user, password }, onReady, onClose, onError) => {
-        const client = new Client();
-        client.on('ready', () => client.shell((error, clientStream) => {
-            if(error) return onError(error);
-            clientStream.on('unpipe', () => {
-                onClose(clientStream);
-                client.end();
-            });
-            onReady(clientStream);
-        }));
-        client.on('error', onError);
-        client.connect({
-            host: address,
-            port,
-            username: user,
-            password
-        });
+    chainedSession: (hostsChain, onReady, onClose, onError) => {
+        const clients = [];
+        (async () => {
+            for(let i = 0; i < hostsChain.length; i++){
+                const
+                    prevClient = clients[i-1],
+                    { address, port, user, password } = hostsChain[i],
+                    nextHost = hostsChain[i+1],
+                    client = clients[i] = new Client();
+                client.on('error', onError);
+                await new Promise(resolve => {
+                    client.on('ready', () => {
+                        if(nextHost) resolve();
+                        else {
+                            client.shell((error, clientStream) => {
+                                if(error) return onError(error);
+                                clientStream.on('unpipe', () => {
+                                    onClose(clientStream);
+                                    client.end();
+                                });
+                                onReady(clientStream);
+                            });
+                        }
+                    });
+                    if(prevClient){
+                        client.on('end', () => prevClient.end());
+                        prevClient.forwardOut('127.0.0.1', 12345 + i, address, port, (error, prevClientStream) => {
+                            if(error) onError(error);
+                            client.connect({
+                                sock: prevClientStream,
+                                username: user,
+                                password
+                            });
+                        });
+                    }
+                    else client.connect({
+                        host: address,
+                        port,
+                        username: user,
+                        password
+                    });
+                });
+            }
+        })();
     }
 };

lib/tui/index.js

@@ -536,7 +536,7 @@ const getControllers = (stream, end) => {
                         return _controllers.main(user);
                     }
                     case 'connect': {
-                        return ssh.session(host, clientStream => {
+                        return ssh.chainedSession([host], clientStream => {
                             screen.destroy();
                             clientStream.stdout.pipe(stream.stdin);
                             stream.stdin.pipe(clientStream.stdout);