[Important] allow sending data ONLY notifications for FCM notifi… (#453)

* allow sending data ONLY notifications for FCM notifications

ran into a little issue here need this tweak to be able to send and process background notifications on android

If you want to process android notifications in the BACKGROUND, they need to be data notifications, as in not contain the "notification" key in the payload.

This little change achieves it, because omitempty on structs for the JSON encoding does not work on sub-structs except if it is a pointer to it and set to nil.
Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>

gorush/notification.go

@@ -70,15 +70,15 @@ type PushNotification struct {
 	Retry            int         `json:"retry,omitempty"`
 
 	// Android
-	APIKey                string           `json:"api_key,omitempty"`
-	To                    string           `json:"to,omitempty"`
-	CollapseKey           string           `json:"collapse_key,omitempty"`
-	DelayWhileIdle        bool             `json:"delay_while_idle,omitempty"`
-	TimeToLive            *uint            `json:"time_to_live,omitempty"`
-	RestrictedPackageName string           `json:"restricted_package_name,omitempty"`
-	DryRun                bool             `json:"dry_run,omitempty"`
-	Condition             string           `json:"condition,omitempty"`
-	Notification          fcm.Notification `json:"notification,omitempty"`
+	APIKey                string            `json:"api_key,omitempty"`
+	To                    string            `json:"to,omitempty"`
+	CollapseKey           string            `json:"collapse_key,omitempty"`
+	DelayWhileIdle        bool              `json:"delay_while_idle,omitempty"`
+	TimeToLive            *uint             `json:"time_to_live,omitempty"`
+	RestrictedPackageName string            `json:"restricted_package_name,omitempty"`
+	DryRun                bool              `json:"dry_run,omitempty"`
+	Condition             string            `json:"condition,omitempty"`
+	Notification          *fcm.Notification `json:"notification,omitempty"`
 
 	// iOS
 	Expiration  *int64   `json:"expiration,omitempty"`

gorush/notification_fcm.go

@@ -60,19 +60,21 @@ func GetAndroidNotification(req PushNotification) *fcm.Message {
 		}
 	}
 
-	notification.Notification = &req.Notification
+	notification.Notification = req.Notification
 
-	// Set request message if body is empty
-	if len(req.Message) > 0 {
-		notification.Notification.Body = req.Message
-	}
+	if req.Notification != nil {
+		// Set request message if body is empty
+		if len(req.Message) > 0 {
+			notification.Notification.Body = req.Message
+		}
 
-	if len(req.Title) > 0 {
-		notification.Notification.Title = req.Title
-	}
+		if len(req.Title) > 0 {
+			notification.Notification.Title = req.Title
+		}
 
-	if v, ok := req.Sound.(string); ok && len(v) > 0 {
-		notification.Notification.Sound = v
+		if v, ok := req.Sound.(string); ok && len(v) > 0 {
+			notification.Notification.Sound = v
+		}
 	}
 
 	return notification

gorush/notification_fcm_test.go

@@ -235,9 +235,10 @@ func TestAndroidNotificationStructure(t *testing.T) {
 			"a": "1",
 			"b": 2,
 		},
-		Notification: fcm.Notification{
+		Notification: &fcm.Notification{
 			Color: test,
 			Tag:   test,
+			Body:  "",
 		},
 	}
 
@@ -263,6 +264,9 @@ func TestAndroidNotificationStructure(t *testing.T) {
 	req = PushNotification{
 		Tokens: []string{"a", "b"},
 		To:     test,
+		Notification: &fcm.Notification{
+			Body: "",
+		},
 	}
 	notification = GetAndroidNotification(req)