fix(pkg/board): handle adb connection error

Author: lucarin91

pkg/board/remote/adb/adb.go

@@ -36,7 +36,13 @@ import (
 	"github.com/arduino/arduino-app-cli/pkg/x/ports"
 )
 
-const username = "arduino"
+var (
+	// NotFoundErr is returned when the ADB device is not found.
+	NotFoundErr = fmt.Errorf("ADB device not found")
+	// DeviceOfflineErr is returned when the ADB device is not reachable.
+	// This usually requires a restart of the adbd server daemon on the device.
+	DeviceOfflineErr = fmt.Errorf("ADB device is offline")
+)
 
 type ADBConnection struct {
 	adbPath string
@@ -46,15 +52,21 @@ type ADBConnection struct {
 // Ensures ADBConnection implements the RemoteConn interface at compile time.
 var _ remote.RemoteConn = (*ADBConnection)(nil)
 
+const username = "arduino"
+
 func FromSerial(serial string, adbPath string) (*ADBConnection, error) {
 	if adbPath == "" {
 		adbPath = FindAdbPath()
 	}
 
-	return &ADBConnection{
-		host:    serial,
-		adbPath: adbPath,
-	}, nil
+	conn := ADBConnection{host: serial, adbPath: adbPath}
+	if connected, err := conn.IsConnected(); err != nil {
+		return nil, err
+	} else if !connected {
+		return nil, fmt.Errorf("device %s is not connected", serial)
+	}
+
+	return &conn, nil
 }
 
 func FromHost(host string, adbPath string) (*ADBConnection, error) {
@@ -71,6 +83,26 @@ func FromHost(host string, adbPath string) (*ADBConnection, error) {
 	return FromSerial(host, adbPath)
 }
 
+// IsConnected checks if the ADB device is connected and online.
+func (a *ADBConnection) IsConnected() (bool, error) {
+	cmd, err := paths.NewProcess(nil, a.adbPath, "-s", a.host, "get-state")
+	if err != nil {
+		return false, fmt.Errorf("failed to create ADB command: %w", err)
+	}
+
+	output, err := cmd.RunAndCaptureCombinedOutput(context.TODO())
+	if err != nil {
+		if bytes.Contains(output, []byte("device offline")) {
+			return false, DeviceOfflineErr
+		} else if bytes.Contains(output, []byte("not found")) {
+			return false, NotFoundErr
+		}
+		return false, fmt.Errorf("failed to get ADB device state: %w: %s", err, output)
+	}
+
+	return string(bytes.TrimSpace(output)) == "device", nil
+}
+
 func (a *ADBConnection) Forward(ctx context.Context, localPort int, remotePort int) error {
 	if !ports.IsAvailable(localPort) {
 		return remote.ErrPortAvailable