[FIX] config manager bugs and improve error handling

Author: valentin-kaiser

config/core.go

@@ -350,5 +350,5 @@ func Changed(o, n any) bool {
 func (m *manager) set(appConfig Config) {
 	mutex.Lock()
 	defer mutex.Unlock()
-	cm.config = appConfig
+	m.config = appConfig
 }

config/file.go

@@ -70,7 +70,7 @@ func (m *manager) watch(onChange func(fsnotify.Event)) error {
 		}
 	}()
 
-	return m.watcher.Add(configFile)
+	return m.watcher.Add(filepath.Clean(filepath.Dir(configFile)))
 }
 
 // save saves the configuration to the file

config/unmarshal.go

@@ -151,33 +151,38 @@ func setFieldValue(field reflect.Value, value interface{}) error {
 		}
 		// Handle signed integers from YAML (convert to unsigned if non-negative)
 		if i, ok := value.(int); ok {
-			if i >= 0 {
-				field.SetUint(uint64(i))
+			if i < 0 {
+				return fmt.Errorf("negative integer %d cannot be converted to unsigned", i)
 			}
+			field.SetUint(uint64(i))
 			return nil
 		}
 		if i, ok := value.(int64); ok {
-			if i >= 0 {
-				field.SetUint(uint64(i))
+			if i < 0 {
+				return fmt.Errorf("negative integer %d cannot be converted to unsigned", i)
 			}
+			field.SetUint(uint64(i))
 			return nil
 		}
 		if i, ok := value.(int32); ok {
-			if i >= 0 {
-				field.SetUint(uint64(i))
+			if i < 0 {
+				return fmt.Errorf("negative integer %d cannot be converted to unsigned", i)
 			}
+			field.SetUint(uint64(i))
 			return nil
 		}
 		if i, ok := value.(int16); ok {
-			if i >= 0 {
-				field.SetUint(uint64(i))
+			if i < 0 {
+				return fmt.Errorf("negative integer %d cannot be converted to unsigned", i)
 			}
+			field.SetUint(uint64(i))
 			return nil
 		}
 		if i, ok := value.(int8); ok {
-			if i >= 0 {
-				field.SetUint(uint64(i))
+			if i < 0 {
+				return fmt.Errorf("negative integer %d cannot be converted to unsigned", i)
 			}
+			field.SetUint(uint64(i))
 			return nil
 		}
 		if str, ok := value.(string); ok {

web/jrpc/jrpc.go

@@ -94,6 +94,7 @@ var (
 	errRequestMustBePointer     = apperror.NewError("request must be a pointer")
 	errNilRequest               = apperror.NewError("nil request")
 	errExpectedProtoMessage     = apperror.NewError("expected proto.Message for request")
+	errExpectedError            = apperror.NewError("expected error type in method return value")
 
 	// Cached reflection types to avoid repeated type operations
 	contextType = reflect.TypeOf((*context.Context)(nil)).Elem()
@@ -540,7 +541,7 @@ func (s *Service) call(ctx context.Context, service, method string, req proto.Me
 		var ok bool
 		err, ok = e.(error)
 		if !ok {
-			return nil, errExpectedProtoMessage
+			return nil, errExpectedError
 		}
 	}