Progress on supporting IPv6 (#805)

* Progress on supporting IPv6

* Apply suggestions from code review

Co-authored-by: James Sumners <james@sumners.email>

* tests: add IPv6 URL format test to server.test.js

Co-authored-by: James Sumners <james@sumners.email>

lib/server.js

@@ -508,7 +508,15 @@ Object.defineProperties(Server.prototype, {
       } else {
         str = 'ldap://'
       }
-      str += this.host + ':' + this.port
+
+      let host = this.host
+      // Node 18 switched family from returning a string to returning a number
+      // https://nodejs.org/api/net.html#serveraddress
+      if (addr.family === 'IPv6' || addr.family === 6) {
+        host = '[' + this.host + ']'
+      }
+
+      str += host + ':' + this.port
       return str
     },
     configurable: false

test/server.test.js

@@ -24,7 +24,7 @@ tap.test('basic create', function (t) {
 tap.test('connection count', function (t) {
   const server = ldap.createServer()
   t.ok(server)
-  server.listen(0, 'localhost', function () {
+  server.listen(0, '127.0.0.1', function () {
     t.ok(true, 'server listening on ' + server.url)
 
     server.getConnections(function (err, count) {
@@ -62,6 +62,17 @@ tap.test('properties', function (t) {
   })
 })
 
+tap.test('IPv6 URL is formatted correctly', function (t) {
+  const server = ldap.createServer()
+  t.equal(server.url, null, 'url empty before bind')
+  server.listen(0, '::1', function () {
+    t.ok(server.url)
+    t.equal(server.url, 'ldap://[::1]:' + server.port)
+
+    server.close(() => t.end())
+  })
+})
+
 tap.test('listen on unix/named socket', function (t) {
   const server = ldap.createServer()
   server.listen(t.context.sock, function () {
@@ -437,7 +448,7 @@ tap.test('multithreading support via external server', function (t) {
     config: serverOptions
   }
   t.ok(server)
-  fauxServer.listen(5555, 'localhost', function () {
+  fauxServer.listen(5555, '127.0.0.1', function () {
     t.ok(true, 'server listening on ' + server.url)
 
     t.ok(fauxServer)
@@ -459,7 +470,7 @@ tap.test('multithreading support via hook', function (t) {
   const server = ldap.createServer(serverOptions)
   const fauxServer = ldap.createServer(serverOptions)
   t.ok(server)
-  fauxServer.listen(0, 'localhost', function () {
+  fauxServer.listen(0, '127.0.0.1', function () {
     t.ok(true, 'server listening on ' + server.url)
 
     t.ok(fauxServer)