test(watch): test error return scenario

infrastructure/file_watcher.go

@@ -9,7 +9,7 @@ import (
 	"github.com/lucaschain/beholder/core/event_types"
 )
 
-func loop(watcher *fsnotify.Watcher, callback core.ChangeCallback) {
+func loop(watcher *fsnotify.Watcher, callback core.ChangeCallback) *error {
 	for {
 		select {
 		case event, ok := <-watcher.Events:
@@ -20,7 +20,10 @@ func loop(watcher *fsnotify.Watcher, callback core.ChangeCallback) {
 				Type:     event_types.FromString(event.Op.String()),
 				FileName: event.Name,
 			}
-			callback(&changeEvent, nil)
+			err := callback(&changeEvent, nil)
+			if err != nil {
+				return err
+			}
 		case err, _ := <-watcher.Errors:
 			if err != nil {
 				callback(nil, &err)
@@ -29,15 +32,19 @@ func loop(watcher *fsnotify.Watcher, callback core.ChangeCallback) {
 	}
 }
 
-func FileWatcher(paths []string, callback core.ChangeCallback, ctx context.Context) {
+func FileWatcher(paths []string, callback core.ChangeCallback, ctx context.Context) *error {
 	watcher, err := fsnotify.NewWatcher()
 	if err != nil {
 		callback(nil, &err)
 	}
 	defer watcher.Close()
 
 	go func() {
-		loop(watcher, callback)
+		commandError := loop(watcher, callback)
+
+		if commandError != nil {
+			ctx.Done()
+		}
 	}()
 
 	for _, path := range paths {
@@ -48,4 +55,7 @@ func FileWatcher(paths []string, callback core.ChangeCallback, ctx context.Conte
 	}
 
 	<-ctx.Done()
+
+	err = ctx.Err()
+	return &err
 }

use_case/watch.go

@@ -15,7 +15,7 @@ type WatchConfig struct {
 	AllowFailing bool
 }
 
-type FileWatcher func(paths []string, callback core.ChangeCallback, ctx context.Context)
+type FileWatcher func(paths []string, callback core.ChangeCallback, ctx context.Context) *error
 type CommandRunner func(command []string) error
 
 func onFileChange(c WatchConfig, commandRunner CommandRunner) core.ChangeCallback {
@@ -28,7 +28,7 @@ func onFileChange(c WatchConfig, commandRunner CommandRunner) core.ChangeCallbac
 			command := core.CommandTokens(c.Command, event)
 			commandError := commandRunner(command)
 
-			if commandError != nil && !c.AllowFailing {
+			if commandError != nil && c.AllowFailing {
 				return &commandError
 			}
 		}
@@ -40,8 +40,9 @@ func Watch(
 	c WatchConfig,
 	fileWatcher FileWatcher,
 	commandRunner CommandRunner,
-) {
+) *error {
 	fmt.Printf("Watching path: %s and running command: '%s'\n", c.Paths, c.Command)
 	callback := onFileChange(c, commandRunner)
-	fileWatcher(c.Paths, callback, context.Background())
+
+	return fileWatcher(c.Paths, callback, context.Background())
 }

use_case/watch_test.go

@@ -68,9 +68,10 @@ func TestWatch(t *testing.T) {
 
 		var returnedError error
 		var fakeErr error
-		fakeWatcher := func(paths []string, callback core.ChangeCallback, ctx context.Context) {
+		fakeWatcher := func(paths []string, callback core.ChangeCallback, ctx context.Context) *error {
 			fakeErr = errors.New("error")
 			returnedError = *callback(nil, &fakeErr)
+			return nil
 		}
 
 		use_case.Watch(config, fakeWatcher, func(command []string) error { return nil })
@@ -84,23 +85,22 @@ func TestWatch(t *testing.T) {
 		config.Command = []string{"echo", "{type}", "{file}"}
 		config.AllowFailing = true
 
-		var returnedError error
 		commandError := errors.New("error")
 		fakeRunner := func(command []string) error {
 			return commandError
 		}
 
 		fakeWatcher := buildFakeFileWatcher("test.txt", event_types.Create)
-		use_case.Watch(config, fakeWatcher, fakeRunner)
+		err := use_case.Watch(config, fakeWatcher, fakeRunner)
 
-		assert.Equal(t, commandError, returnedError)
+		assert.Equal(t, commandError, *err)
 	})
 }
 
 func buildFakeErrorFileWatcher() use_case.FileWatcher {
-	return func(paths []string, callback core.ChangeCallback, ctx context.Context) {
+	return func(paths []string, callback core.ChangeCallback, ctx context.Context) *error {
 		error := errors.New("error")
-		callback(nil, &error)
+		return callback(nil, &error)
 	}
 }
 
@@ -113,8 +113,8 @@ func buildFakeFileWatcher(filename string, eventType event_types.EventType) use_
 		Type:     event_types.Create,
 		FileName: filename,
 	}
-	return func(paths []string, callback core.ChangeCallback, ctx context.Context) {
-		callback(event, nil)
+	return func(paths []string, callback core.ChangeCallback, ctx context.Context) *error {
+		return callback(event, nil)
 	}
 }