filefabric: fix directory move after API change #5734

The API has changed in the directory move call JSON response from
returning a TaskID as a string to returning it as an integer. In other
places it is still returned as a string though.

This patch allows the TaskID to be an integer or a string in the JSON
response and keeps it internally as a string like before.

backend/filefabric/api/types.go

@@ -69,11 +69,29 @@ func (i *Int) UnmarshalJSON(data []byte) error {
 	return json.Unmarshal(data, (*int)(i))
 }
 
+// String represents an string which can be represented in JSON as a
+// quoted string or an integer.
+type String string
+
+// MarshalJSON turns a String into JSON
+func (s *String) MarshalJSON() (out []byte, err error) {
+	return json.Marshal((*string)(s))
+}
+
+// UnmarshalJSON turns JSON into a String
+func (s *String) UnmarshalJSON(data []byte) error {
+	err := json.Unmarshal(data, (*string)(s))
+	if err != nil {
+		*s = String(data)
+	}
+	return nil
+}
+
 // Status return returned in all status responses
 type Status struct {
 	Code    string `json:"status"`
 	Message string `json:"statusmessage"`
-	TaskID  string `json:"taskid"`
+	TaskID  String `json:"taskid"`
 	// Warning string `json:"warning"` // obsolete
 }
 

backend/filefabric/filefabric.go

@@ -844,7 +844,7 @@ func (f *Fs) Purge(ctx context.Context, dir string) error {
 }
 
 // Wait for the the background task to complete if necessary
-func (f *Fs) waitForBackgroundTask(ctx context.Context, taskID string) (err error) {
+func (f *Fs) waitForBackgroundTask(ctx context.Context, taskID api.String) (err error) {
 	if taskID == "" || taskID == "0" {
 		// No task to wait for
 		return nil