From 51961dd737e709c3f274608b3cf89376b2df0d47 Mon Sep 17 00:00:00 2001
From: Zheng-Xiang Ke <kf99916@gmail.com>
Date: Sat, 6 Jan 2018 10:22:44 +0800
Subject: [PATCH] Migrate external storage

---
 Sources/DataStack+Migration.swift | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Sources/DataStack+Migration.swift b/Sources/DataStack+Migration.swift
index c6dec22..339c478 100644
--- a/Sources/DataStack+Migration.swift
+++ b/Sources/DataStack+Migration.swift
@@ -796,6 +796,11 @@ public extension DataStack {
             throw CoreStoreError(error)
         }
         
+        let externalStorageDirName = "." + fileURL.deletingPathExtension().lastPathComponent + "_SUPPORT"
+        let temporaryExtenralStorageURL = temporaryDirectoryURL.appendingPathComponent(
+            externalStorageDirName,
+            isDirectory: true
+        )
         do {
             
             try fileManager.replaceItem(
@@ -806,11 +811,23 @@ public extension DataStack {
                 resultingItemURL: nil
             )
             
+            if fileManager.fileExists(atPath: temporaryExtenralStorageURL.path) {
+                let extenralStorageURL = fileURL.deletingLastPathComponent().appendingPathComponent(externalStorageDirName,  isDirectory: true)
+                try fileManager.replaceItem(
+                    at: extenralStorageURL as URL,
+                    withItemAt: temporaryExtenralStorageURL,
+                    backupItemName: nil,
+                    options: [],
+                    resultingItemURL: nil
+                )
+            }
+            
             progress.completedUnitCount = progress.totalUnitCount
         }
         catch {
             
             _ = try? fileManager.removeItem(at: temporaryFileURL)
+            _ = try? fileManager.removeItem(at: temporaryExtenralStorageURL)
             throw CoreStoreError(error)
         }
     }