fix: Handle EADDRNOTAVAIL if IPv6 not enabled (#93)

The logic will now disable IPv6 lookups when this error happens after we resolved a hostname to IPv6. If someone provides an IPv6 address as host themselves we would fail as before.

lib/wait-port.js

@@ -4,6 +4,8 @@ const outputFunctions = require('./output-functions');
 const validateParameters = require('./validate-parameters');
 const ConnectionError = require('./errors/connection-error');
 
+let IPv6enabled = true;
+
 function createConnectionWithTimeout({ host, port, ipVersion }, timeout, callback) {
   //  Variable to hold the timer we'll use to kill the socket if we don't
   //  connect in time.
@@ -114,6 +116,15 @@ function tryConnect(options, timeout) {
             // ...otherwise, we will explicitly fail with a meaningful error for
             //  the user.
             return reject(new ConnectionError(`The address '${options.host}' cannot be found`));
+          } else if (err.code === 'EADDRNOTAVAIL' && options.ipVersion === 6) {
+            //  This will occur if the IP address we are trying to connect to does not exist
+            //  This can happen for ::1 or other IPv6 addresses if the IPv6 stack is not enabled.
+            //  In this case we disable the IPv6 lookup
+            debug('Socket cannot be opened for IPv6: EADDRNOTAVAIL');
+            debug('Disabling IPv6 lookup');
+            IPv6enabled = false;
+
+            return resolve(false);
           }
 
           //  Trying to open the socket has resulted in an error we don't
@@ -208,7 +219,7 @@ function waitPort(params) {
           }
 
           // Check for IPv6 next
-          if (ipVersion === 4 && !net.isIP(host)) {
+          if (IPv6enabled && ipVersion === 4 && !net.isIP(host)) {
             return loop(6);
           }