Allow uploads without port selection

It is common for a "port" to be used in some way during the process of uploading to a board. However, the array of
Arduino boards is very diverse. Some of these do not produce a port and their upload method has no need for one.

For this reason, the IDE must allow the upload process to be initiated regardless of whether a port happens to be
selected. During the addition of support for user provided fields, an unwarranted assumption was made that all boards
require a port selection for upload and this resulted in a regression that broke uploading for these boards. This
regression was especially user unfriendly in that there was no response whatsoever from the IDE when the user attempted
to initiate an upload under these conditions.

The bug is hereby fixed. The upload process will always be initiated by the IDE regardless of whether a port is
selected. In cases where a port is required, the resulting error message returned by Arduino CLI or the upload tool will
communicate the problem to the user.

Author: per1234

Diff for: arduino-ide-extension/src/browser/boards/boards-service-provider.ts

@@ -409,14 +409,16 @@ export class BoardsServiceProvider
   }
 
   async selectedBoardUserFields(): Promise<BoardUserField[]> {
-    if (!this._boardsConfig.selectedBoard || !this._boardsConfig.selectedPort) {
+    if (!this._boardsConfig.selectedBoard) {
       return [];
     }
     const fqbn = this._boardsConfig.selectedBoard.fqbn;
     if (!fqbn) {
       return [];
     }
-    const protocol = this._boardsConfig.selectedPort.protocol;
+    // Protocol must be set to `default` when uploading without a port selected:
+    // https://arduino.github.io/arduino-cli/dev/platform-specification/#sketch-upload-configuration
+    const protocol = this._boardsConfig.selectedPort?.protocol || 'default';
     return await this.boardsService.getBoardUserFields({ fqbn, protocol });
   }
 

Diff for: arduino-ide-extension/src/browser/contributions/user-fields.ts

@@ -66,10 +66,8 @@ export class UserFields extends Contribution {
     }
     const address =
       boardsConfig.selectedBoard?.port?.address ||
-      boardsConfig.selectedPort?.address;
-    if (!address) {
-      return undefined;
-    }
+      boardsConfig.selectedPort?.address ||
+      '';
     return fqbn + '|' + address;
   }