fix: skip config validation when using connector

This changeset fixes a problem in the original custom `connector`
factory method implementation that required the `server` config property
to be defined even though its value is ignored.

Removing the validation when `config.options.connector` is defined fixes
the problem.

Ref: tediousjs#1540
Fixes: tediousjs#1541
Signed-off-by: Ruy Adorno <ruyadorno@google.com>

src/connection.ts

@@ -1052,7 +1052,7 @@ class Connection extends EventEmitter {
       throw new TypeError('The "config" argument is required and must be of type Object.');
     }
 
-    if (typeof config.server !== 'string') {
+    if (typeof config.server !== 'string' && !config.options!.connector) {
       throw new TypeError('The "config.server" property is required and must be of type string.');
     }
 
@@ -1902,6 +1902,9 @@ class Connection extends EventEmitter {
 
     if (this.config.options.port) {
       return this.connectOnPort(this.config.options.port, this.config.options.multiSubnetFailover, signal, this.config.options.connector);
+    } else if (this.config.options.connector) {
+      // port and multiSubnetFailover are not used when using a custom connector
+      return this.connectOnPort(0, false, signal, this.config.options.connector);
     } else {
       return instanceLookup({
         server: this.config.server,

test/unit/custom-connector.js

@@ -28,7 +28,6 @@ describe('custom connector', function() {
     const host = server.address().address;
     const port = server.address().port;
     const connection = new Connection({
-      server: host,
       options: {
         connector: async () => {
           customConnectorCalled = true;
@@ -37,7 +36,6 @@ describe('custom connector', function() {
             port,
           });
         },
-        port
       },
     });