Avoid double buffering of command output in getFirmwareVersion

Author: cmaglie

cli/firmware/getversion.go

@@ -19,7 +19,6 @@
 package firmware
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"log"
@@ -85,13 +84,10 @@ func runGetVersion(cmd *cobra.Command, args []string) {
 }
 
 func getVersionWithPlugin(uploader *plugin.FwUploader) *flasher.FlashResult {
-	stdoutBuffer := &bytes.Buffer{}
-	stderrBuffer := &bytes.Buffer{}
-	stdout := io.Writer(os.Stdout)
-	stderr := io.Writer(os.Stderr)
+	var stdout, stderr io.Writer
 	if feedback.GetFormat() == feedback.Text {
-		stdout = io.MultiWriter(stdoutBuffer, os.Stdout)
-		stderr = io.MultiWriter(stderrBuffer, os.Stderr)
+		stdout = os.Stdout
+		stderr = os.Stderr
 	}
 	res, err := uploader.GetFirmwareVersion(commonFlags.Address, stdout, stderr)
 	if err != nil {
@@ -100,8 +96,8 @@ func getVersionWithPlugin(uploader *plugin.FwUploader) *flasher.FlashResult {
 
 	return &flasher.FlashResult{
 		Programmer: (&flasher.ExecOutput{
-			Stdout: stdoutBuffer.String(),
-			Stderr: stderrBuffer.String(),
+			Stdout: string(res.Stdout),
+			Stderr: string(res.Stderr),
 		}),
 		Version: res.FirmwareVersion.String(),
 	}

plugin/plugin.go

@@ -89,9 +89,12 @@ func (uploader *FwUploader) GetFirmwareVersion(portAddress string, stdout, stder
 	if portAddress != "" {
 		args = append(args, "-p", portAddress)
 	}
-	execStdout, _, execErr := uploader.exec(stdout, stderr, args...)
+	execStdout, execStderr, execErr := uploader.exec(stdout, stderr, args...)
 
-	res := &GetFirmwareVersionResult{}
+	res := &GetFirmwareVersionResult{
+		Stdout: execStdout.Bytes(),
+		Stderr: execStderr.Bytes(),
+	}
 	fwVersionPrefix := "FIRMWARE-VERSION: "
 	fwErrorPrefix := "GET-VERSION-ERROR: "
 	for _, line := range strings.Split(execStdout.String(), "\n") {
@@ -118,6 +121,8 @@ func (uploader *FwUploader) GetFirmwareVersion(portAddress string, stdout, stder
 type GetFirmwareVersionResult struct {
 	FirmwareVersion *semver.RelaxedVersion
 	Error           string
+	Stdout          []byte
+	Stderr          []byte
 }
 
 // FlashFirmware runs the plugin to flash the selected firmware