refactor errors to use Go 1.13 errors.Is

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"brainbaking.com/restictray/restic"
+	"errors"
 	"fyne.io/systray"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
@@ -66,9 +67,8 @@ func main() {
 func updateSnapshots(cnf *restic.Config, mnu *resticmenu) {
 	err := wrapper.UpdateLatestSnapshots(cnf)
 	if err != nil {
-		te, ok := err.(*restic.ResticCmdTimeoutError)
-		if ok {
-			log.Warn().Err(te).Msg("update snapshot timeout")
+		if errors.Is(err, restic.ResticCmdTimeoutError) {
+			log.Warn().Err(err).Msg("update snapshot timeout")
 			mnu.latestSnapshot.SetTitle("‼️ Latest: timeout while updating")
 			mnu.backupNowEnable()
 		} else {

restic/wrapper.go

@@ -27,13 +27,7 @@ type Wrapper struct {
 	mountCommand    *exec.Cmd
 }
 
-type ResticCmdTimeoutError struct {
-	KillErr error
-}
-
-func (r *ResticCmdTimeoutError) Error() string {
-	return fmt.Errorf("backup output timeout, repository server down?: %w", r.KillErr).Error()
-}
+var ResticCmdTimeoutError = errors.New("backup output timeout, repository server down?")
 
 func (w *Wrapper) HasSnapshots() bool {
 	return len(w.LatestSnapshots) > 0
@@ -130,9 +124,8 @@ func (w *Wrapper) UpdateLatestSnapshots(c *Config) error {
 	select {
 	case <-done:
 	case <-time.After(cmdTimeout):
-		return &ResticCmdTimeoutError{
-			KillErr: cmd.Process.Kill(),
-		}
+		cmd.Process.Kill()
+		return fmt.Errorf("restic snapshots cmd: %w", ResticCmdTimeoutError)
 	}
 
 	if err != nil {
@@ -173,9 +166,8 @@ func (w *Wrapper) Backup(c *Config) error {
 	case <-busy:
 		busy = nil // It's alive! continue with cmd.Wait()
 	case <-time.After(cmdTimeout):
-		return &ResticCmdTimeoutError{
-			KillErr: cmd.Process.Kill(),
-		}
+		cmd.Process.Kill()
+		return fmt.Errorf("restic snapshots cmd: %w", ResticCmdTimeoutError)
 	}
 
 	err := cmd.Wait()

restic/wrapper_test.go

@@ -189,7 +189,7 @@ func TestBackup_TakesLongerThanNeededToOutput_TimesOut(t *testing.T) {
 	wrapper := Wrapper{}
 	err := wrapper.Backup(&Config{})
 
-	assert.ErrorContainsf(t, err, "backup output timeout", "timeout expected")
+	assert.ErrorIs(t, err, ResticCmdTimeoutError)
 }
 
 func TestUpdateLatestSnapshot_TakesLongerThanNeededToOutput_TimesOut(t *testing.T) {
@@ -200,7 +200,7 @@ func TestUpdateLatestSnapshot_TakesLongerThanNeededToOutput_TimesOut(t *testing.
 	err := wrapper.UpdateLatestSnapshots(&Config{})
 
 	assert.Empty(t, wrapper.LatestSnapshots)
-	assert.ErrorContainsf(t, err, "backup output timeout", "timeout expected")
+	assert.ErrorIs(t, err, ResticCmdTimeoutError)
 }
 
 func TestUpdateLatestSnapshots_FromJSONOutputOfRestic(t *testing.T) {