factor out the programmer flag handling

cli/arguments/programmer.go

+// This file is part of arduino-cli.
+//
+// Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+
+package arguments
+
+import "github.com/spf13/cobra"
+
+// Programmer contains the programmer flag data.
+// This is useful so all flags used by commands that need
+// this information are consistent with each other.
+type Programmer struct {
+	programmer string
+}
+
+// AddToCommand adds the flags used to set the programmer to the specified Command
+func (p *Programmer) AddToCommand(cmd *cobra.Command) {
+	cmd.Flags().StringVarP(&p.programmer, "programmer", "P", "", tr("Programmer to use, e.g: atmel_ice"))
+	cmd.RegisterFlagCompletionFunc("programmer", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		return GetInstalledProgrammers(), cobra.ShellCompDirectiveDefault
+	})
+}
+
+// String returns the programmer
+func (p *Programmer) String() string {
+	return p.programmer
+}

cli/burnbootloader/burnbootloader.go

@@ -34,7 +34,7 @@ var (
 	port       arguments.Port
 	verbose    bool
 	verify     bool
-	programmer string
+	programmer arguments.Programmer
 	dryRun     bool
 	tr         = i18n.Tr
 )
@@ -52,12 +52,9 @@ func NewCommand() *cobra.Command {
 
 	fqbn.AddToCommand(burnBootloaderCommand)
 	port.AddToCommand(burnBootloaderCommand)
+	programmer.AddToCommand(burnBootloaderCommand)
 	burnBootloaderCommand.Flags().BoolVarP(&verify, "verify", "t", false, tr("Verify uploaded binary after the upload."))
 	burnBootloaderCommand.Flags().BoolVarP(&verbose, "verbose", "v", false, tr("Turns on verbose mode."))
-	burnBootloaderCommand.Flags().StringVarP(&programmer, "programmer", "P", "", tr("Use the specified programmer to upload."))
-	burnBootloaderCommand.RegisterFlagCompletionFunc("programmer", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
-		return arguments.GetInstalledProgrammers(), cobra.ShellCompDirectiveDefault
-	})
 	burnBootloaderCommand.Flags().BoolVar(&dryRun, "dry-run", false, tr("Do not perform the actual upload, just log out actions"))
 	burnBootloaderCommand.Flags().MarkHidden("dry-run")
 
@@ -80,7 +77,7 @@ func run(command *cobra.Command, args []string) {
 		Port:       discoveryPort.ToRPC(),
 		Verbose:    verbose,
 		Verify:     verify,
-		Programmer: programmer,
+		Programmer: programmer.String(),
 		DryRun:     dryRun,
 	}, os.Stdout, os.Stderr); err != nil {
 		feedback.Errorf(tr("Error during Upload: %v"), err)