refactor: Drop handlePanic dependency from file watcher and instead…

… use `errors.Join` like usual

Signed-off-by: Felicitas Pojtinger <felicitas@pojtinger.com>

hydrapp/pkg/ui/browser_launcher.go

@@ -38,6 +38,7 @@ var (
 	ErrCouldNotCreateEpiphanyProfileDirectory                = errors.New("could not create Epiphany profile directory")
 	ErrCouldNotWriteDesktopFile                              = errors.New("could not write desktop file")
 	ErrCouldNotFindSupportedBrowser                          = errors.New("could not find a supported browser")
+	ErrCouldNotWaitForBrowserLockfileRemoval                 = errors.New("could not wait for browser lockfile removal")
 )
 
 type Browser struct {
@@ -294,7 +295,9 @@ func LaunchBrowser(
 		}
 
 		// Wait till lock for browser has been removed
-		utils.WaitForFileRemoval(filepath.Join(userDataDir, "SingletonSocket"), handlePanic)
+		if err := utils.WaitForFileRemoval(filepath.Join(userDataDir, "SingletonSocket")); err != nil {
+			handlePanic(ErrCouldNotWaitForBrowserLockfileRemoval.Error(), errors.Join(ErrCouldNotWaitForBrowserLockfileRemoval, err))
+		}
 
 		// Launch Firefox-like browser
 	case BrowserTypeFirefox:
@@ -406,7 +409,9 @@ func LaunchBrowser(
 		}
 
 		// Wait till lock for browser has been removed
-		utils.WaitForFileRemoval(filepath.Join(profileDir, "cookies.sqlite-wal"), handlePanic)
+		if err := utils.WaitForFileRemoval(filepath.Join(profileDir, "cookies.sqlite-wal")); err != nil {
+			handlePanic(ErrCouldNotWaitForBrowserLockfileRemoval.Error(), errors.Join(ErrCouldNotWaitForBrowserLockfileRemoval, err))
+		}
 
 		// Launch Epiphany-like browser
 	case BrowserTypeEpiphany:
@@ -470,7 +475,9 @@ func LaunchBrowser(
 		}
 
 		// Wait till lock for browser has been removed
-		utils.WaitForFileRemoval(filepath.Join(profileDir, "ephy-history.db-wal"), handlePanic)
+		if err := utils.WaitForFileRemoval(filepath.Join(profileDir, "ephy-history.db-wal")); err != nil {
+			handlePanic(ErrCouldNotWaitForBrowserLockfileRemoval.Error(), errors.Join(ErrCouldNotWaitForBrowserLockfileRemoval, err))
+		}
 
 		// Launch Lynx-like browser
 	case BrowserTypeLynx:

hydrapp/pkg/utils/filewatcher.go

@@ -1,51 +1,51 @@
 package utils
 
 import (
+	"errors"
 	"os"
 
 	"github.com/fsnotify/fsnotify"
 )
 
-func WaitForFileRemoval(path string, handlePanic func(msg string, err error)) {
+var (
+	ErrCouldNotStartFileWatcher     = errors.New("could not start file watcher")
+	ErrCouldNotAddPathToFileWatcher = errors.New("could not add path to file watcher")
+	ErrCouldNotWatchFile            = errors.New("could not watch file")
+)
+
+func WaitForFileRemoval(path string) error {
 	if _, err := os.Stat(path); err == nil {
 		// Wait until browser has exited
 		watcher, err := fsnotify.NewWatcher()
 		if err != nil {
-			handlePanic("could not start lockfile watcher", err)
+			return errors.Join(ErrCouldNotStartFileWatcher, err)
 		}
 		defer watcher.Close()
 
-		done := make(chan struct{})
-		go func() {
-			for {
-				select {
-				case event, ok := <-watcher.Events:
-					if !ok {
-						return
-					}
-
-					// Stop the app
-					if event.Op&fsnotify.Remove == fsnotify.Remove {
-						done <- struct{}{}
+		if err = watcher.Add(path); err != nil {
+			return errors.Join(ErrCouldNotAddPathToFileWatcher, err)
+		}
 
-						return
-					}
+		for {
+			select {
+			case event, ok := <-watcher.Events:
+				if !ok {
+					return nil
+				}
 
-				case err, ok := <-watcher.Errors:
-					if !ok {
-						return
-					}
+				if event.Op&fsnotify.Remove == fsnotify.Remove {
+					return nil
+				}
 
-					handlePanic("could not continue watching lockfile", err)
+			case err, ok := <-watcher.Errors:
+				if !ok {
+					return nil
 				}
-			}
-		}()
 
-		err = watcher.Add(path)
-		if err != nil {
-			handlePanic("could not watch lockfile", err)
+				return errors.Join(ErrCouldNotWatchFile, err)
+			}
 		}
-
-		<-done
 	}
+
+	return nil
 }