add new server side commands via handleCommand hook

Author: sidorares

lib/connection.js

@@ -100,8 +100,9 @@ class Connection extends EventEmitter {
       handshakeCommand = new Commands.ClientHandshake(this.config.clientFlags);
       handshakeCommand.on('end', () => {
         // this happens when handshake finishes early and first packet is error
-        // and not server hello ( for example, 'Too many connactions' error)
-        if (!handshakeCommand.handshake) {
+        // and not server hello ( for example, 'Too many connections' error)
+        // or server requested auth switch and responded with error to client auth switch data
+        if (!this.authorized) {
           return;
         }
         this._handshakePacket = handshakeCommand.handshake;
@@ -256,7 +257,7 @@ class Connection extends EventEmitter {
     let chunk, offset, header;
     if (length < MAX_PACKET_LENGTH) {
       packet.writeHeader(this.sequenceId);
-      if (this.config.debug) {
+      if (this.config.debug && this._command) {
         // eslint-disable-next-line no-console
         console.log(
           `${this._internalId} ${this.connectionId} <== ${
@@ -425,11 +426,16 @@ class Connection extends EventEmitter {
         );
       }
     }
+    if (!this._command && this.config.isServer) {
+      const commandCode = packet.peekByte();
+      this._command = this.config.serverOptions.handleCommand(commandCode);
+    }
     if (!this._command) {
       this.protocolError(
         'Unexpected packet while no commands in the queue',
         'PROTOCOL_UNEXPECTED_PACKET'
       );
+      console.log()
       this.close();
       return;
     }
@@ -760,7 +766,7 @@ class Connection extends EventEmitter {
     this.writePacket(Packets.ResultSetHeader.toPacket(columns.length));
     columns.forEach(column => {
       this.writePacket(
-        Packets.ColumnDefinition.toPacket(column, this.serverConfig.encoding)
+        Packets.ColumnDefinition.toPacket(column, this.config.serverOptions.encoding)
       );
     });
     this.writeEof();
@@ -769,7 +775,7 @@ class Connection extends EventEmitter {
   // row is array of columns, not hash
   writeTextRow(column) {
     this.writePacket(
-      Packets.TextRow.toPacket(column, this.serverConfig.encoding)
+      Packets.TextRow.toPacket(column, this.config.serverOptions.encoding)
     );
   }
 
@@ -793,16 +799,17 @@ class Connection extends EventEmitter {
     if (!args) {
       args = { affectedRows: 0 };
     }
-    this.writePacket(Packets.OK.toPacket(args, this.serverConfig.encoding));
+    this.writePacket(Packets.OK.toPacket(args, this.config.serverOptions.encoding));
   }
 
   writeError(args) {
     // if we want to send error before initial hello was sent, use default encoding
-    const encoding = this.serverConfig ? this.serverConfig.encoding : 'cesu8';
+    const encoding = this.config.serverOptions.encoding;
     this.writePacket(Packets.Error.toPacket(args, encoding));
   }
 
   serverHandshake(args) {
+    throw new Error('deprecated - use addCommand directly');
     this.serverConfig = args;
     this.serverConfig.encoding =
       CharsetToEncoding[this.serverConfig.characterSet];