Refactor errors

inputcontrol/controller.go

@@ -70,11 +70,15 @@ func RegisterController(name string, init func() (Controller, error), priority i
 }
 
 type UnsupportedPlatformError struct {
-	err error
+	Err error
 }
 
-func (e UnsupportedPlatformError) Error() string {
+func (e *UnsupportedPlatformError) Error() string {
-	return e.err.Error()
+	return e.Err.Error()
+}
+
+func (e *UnsupportedPlatformError) Unwrap() error {
+	return e.Err
 }
 
 type Controller interface {

inputcontrol/controller_portal.go

@@ -55,7 +55,7 @@ func init() {
 func InitPortalController() (Controller, error) {
 	bus, err := dbus.SessionBusPrivate()
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	cleanupBus := true
 	defer func() {
@@ -65,49 +65,49 @@ func InitPortalController() (Controller, error) {
 	}()
 	err = bus.Auth(nil)
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	err = bus.Hello()
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	remoteDesktop := bus.Object("org.freedesktop.portal.Desktop",
 		"/org/freedesktop/portal/desktop")
 	availableDeviceTypesV, err := remoteDesktop.GetProperty(
 		"org.freedesktop.portal.RemoteDesktop.AvailableDeviceTypes")
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	availableDeviceTypes, ok := availableDeviceTypesV.Value().(uint32)
 	if !ok {
-		return nil, UnsupportedPlatformError{errors.New(
+		return nil, &UnsupportedPlatformError{
-			"unexpected 'AvailableDeviceTypes' return type")}
+			errors.New("unexpected 'AvailableDeviceTypes' return type")}
 	}
 	if availableDeviceTypes&deviceKeyboard == 0 ||
 		availableDeviceTypes&devicePointer == 0 {
-		return nil, UnsupportedPlatformError{errors.New(
+		return nil, &UnsupportedPlatformError{
-			"keyboard or pointer source type not supported")}
+			errors.New("keyboard or pointer source type not supported")}
 	}
 	inVardict := make(map[string]dbus.Variant)
 	inVardict["session_handle_token"] = dbus.MakeVariant("t")
 	result, outVardict, err := getResponse(bus, remoteDesktop,
 		"org.freedesktop.portal.RemoteDesktop.CreateSession", 0, inVardict)
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	if result != 0 {
-		return nil, UnsupportedPlatformError{errors.New(fmt.Sprintf(
+		return nil, &UnsupportedPlatformError{
-			"Calling 'CreateSession' failed (%v)", result))}
+			fmt.Errorf("Calling 'CreateSession' failed (%v)", result)}
 	}
 	sessionHandleV, ok := outVardict["session_handle"]
 	if !ok {
-		return nil, UnsupportedPlatformError{errors.New(
+		return nil, &UnsupportedPlatformError{
-			"'session_handle' missing from 'CreateSession' return value")}
+			errors.New("'session_handle' missing from 'CreateSession' return value")}
 	}
 	sessionHandleS, ok := sessionHandleV.Value().(string)
 	if !ok {
-		return nil, UnsupportedPlatformError{errors.New(
+		return nil, &UnsupportedPlatformError{
-			"unexpected 'session_handle' type in 'CreateSession' return value")}
+			errors.New("unexpected 'session_handle' type in 'CreateSession' return value")}
 	}
 	sessionHandle := dbus.ObjectPath(sessionHandleS)
 	inVardict = make(map[string]dbus.Variant)
@@ -115,30 +115,30 @@ func InitPortalController() (Controller, error) {
 	result, outVardict, err = getResponse(bus, remoteDesktop,
 		"org.freedesktop.portal.RemoteDesktop.SelectDevices", 0, sessionHandle, inVardict)
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	if result != 0 {
-		return nil, UnsupportedPlatformError{errors.New(fmt.Sprintf(
+		return nil, &UnsupportedPlatformError{
-			"Calling 'SelectDevices' failed (%v)", result))}
+			fmt.Errorf("Calling 'SelectDevices' failed (%v)", result)}
 	}
 	inVardict = make(map[string]dbus.Variant)
 	result, outVardict, err = getResponse(bus, remoteDesktop,
 		"org.freedesktop.portal.RemoteDesktop.Start", 0, sessionHandle, "", inVardict)
 	if err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	if result != 0 {
 		return nil, errors.New("keyboard or pointer access denied")
 	}
 	devicesV, ok := outVardict["devices"]
 	if !ok {
-		return nil, UnsupportedPlatformError{errors.New(
+		return nil, &UnsupportedPlatformError{
-			"'devices' missing from 'Start' return value")}
+			errors.New("'devices' missing from 'Start' return value")}
 	}
 	devices, ok := devicesV.Value().(uint32)
 	if !ok {
-		return nil, UnsupportedPlatformError{errors.New(
+		return nil, &UnsupportedPlatformError{
-			"unexpected 'devices' type in 'Start' return value")}
+			errors.New("unexpected 'devices' type in 'Start' return value")}
 	}
 	if devices&deviceKeyboard == 0 || devices&devicePointer == 0 {
 		return nil, errors.New("keyboard or pointer access denied")

inputcontrol/controller_windows.go

@@ -98,7 +98,7 @@ func init() {
 func InitWindowsController() (Controller, error) {
 	p := &windowsController{}
 	if err := sendInputProc.Find(); err != nil {
-		return nil, UnsupportedPlatformError{err}
+		return nil, &UnsupportedPlatformError{err}
 	}
 	return p, nil
 }

inputcontrol/controller_x11.go

@@ -61,13 +61,13 @@ func init() {
 func InitX11Controller() (Controller, error) {
 	display := C.XOpenDisplay(nil)
 	if display == nil {
-		return nil, UnsupportedPlatformError{
+		return nil, &UnsupportedPlatformError{
 			errors.New("failed to connect to X server")}
 	}
 	p := &x11Controller{display: display}
 	if p.xIsXwayland() {
 		p.Close()
-		return nil, UnsupportedPlatformError{
+		return nil, &UnsupportedPlatformError{
 			errors.New("X server is Xwayland")}
 	}
 	return p, nil

main.go

@@ -184,21 +184,25 @@ func main() {
 	}
 	var controller inputcontrol.Controller
 	var controllerName string
-	platformErrors := ""
+	var platformErrs []error
 	for _, controllerInfo := range inputcontrol.Controllers {
 		controllerName = controllerInfo.Name
 		var err error
 		controller, err = controllerInfo.Init()
 		if err == nil {
 			break
-		} else if _, ok := err.(inputcontrol.UnsupportedPlatformError); ok {
-			platformErrors += fmt.Sprintf("%s controller: %v\n", controllerName, err)
 		} else {
-			log.Fatalf("%s controller: %v", controllerName, err)
+			var unsupportedErr *inputcontrol.UnsupportedPlatformError
+			wrappedErr := fmt.Errorf("%v controller: %w", controllerName, err)
+			if errors.As(err, &unsupportedErr) {
+				platformErrs = append(platformErrs, wrappedErr)
+			} else {
+				log.Fatal(wrappedErr)
+			}
 		}
 	}
 	if controller == nil {
-		log.Fatal("unsupported platform:\n" + platformErrors)
+		log.Fatal(fmt.Errorf("unsupported platform:\n%w", errors.Join(platformErrs...)))
 	}
 	defer controller.Close()
 	authenticationChallenges := make(chan challenge, authenticationRateBurst)
@@ -241,7 +245,7 @@ func main() {
 				return
 			}
 			if err := processCommand(controller, message); err != nil {
-				log.Printf("%s controller: %v", controllerName, err)
+				log.Print(fmt.Errorf("%s controller: %w", controllerName, err))
 				return
 			}
 		}