From cc346816d6c82f37572df9b15dd9a7bbe1f303af Mon Sep 17 00:00:00 2001
From: John Estropia <rommel.estropia@gmail.com>
Date: Wed, 5 Dec 2018 16:15:20 +0900
Subject: [PATCH] Added new error for cases when addStorageAndWait() is used
 with .allowSynchronousLightweightMigration but migrations are only allowed
 asynchronously (related to #277)

---
 Sources/CSError.swift                         | 11 ++++++++
 ...reStore+CustomDebugStringConvertible.swift |  4 +++
 Sources/CoreStoreError.swift                  | 27 +++++++++++++++++++
 Sources/DataStack.swift                       | 12 +++++++++
 4 files changed, 54 insertions(+)

diff --git a/Sources/CSError.swift b/Sources/CSError.swift
index cec4792..9fb1feb 100644
--- a/Sources/CSError.swift
+++ b/Sources/CSError.swift
@@ -217,6 +217,17 @@ extension CoreStoreError: CoreStoreSwiftType, _ObjectiveCBridgeableError {
                 return
             }
             self = .progressiveMigrationRequired(localStoreURL: localStoreURL)
+
+        case .asynchronousMigrationRequired:
+            guard
+                let localStoreURL = info["localStoreURL"] as? URL,
+                case let nsError as NSError = info["NSError"]
+                else {
+
+                    self = .unknown
+                    return
+            }
+            self = .asynchronousMigrationRequired(localStoreURL: localStoreURL, NSError: nsError)
             
         case .internalError:
             guard case let nsError as NSError = info["NSError"] else {
diff --git a/Sources/CoreStore+CustomDebugStringConvertible.swift b/Sources/CoreStore+CustomDebugStringConvertible.swift
index 0ff72f5..19b37d2 100644
--- a/Sources/CoreStore+CustomDebugStringConvertible.swift
+++ b/Sources/CoreStore+CustomDebugStringConvertible.swift
@@ -137,6 +137,10 @@ extension CoreStoreError: CustomDebugStringConvertible, CoreStoreDebugStringConv
         case .progressiveMigrationRequired(let localStoreURL):
             firstLine = ".progressiveMigrationRequired"
             info.append(("localStoreURL", localStoreURL))
+
+        case .asynchronousMigrationRequired(let localStoreURL):
+            firstLine = ".asynchronousMigrationRequired"
+            info.append(("localStoreURL", localStoreURL))
             
         case .internalError(let NSError):
             firstLine = ".internalError"
diff --git a/Sources/CoreStoreError.swift b/Sources/CoreStoreError.swift
index 824dcd2..9dec792 100644
--- a/Sources/CoreStoreError.swift
+++ b/Sources/CoreStoreError.swift
@@ -53,6 +53,11 @@ public enum CoreStoreError: Error, CustomNSError, Hashable {
      Progressive migrations are disabled for a store, but an `NSMappingModel` could not be found for a specific source and destination model versions.
      */
     case progressiveMigrationRequired(localStoreURL: URL)
+
+    /**
+     The `LocalStorage` was configured with `.allowSynchronousLightweightMigration`, but the model can only be migrated asynchronously.
+     */
+    case asynchronousMigrationRequired(localStoreURL: URL, NSError: NSError)
     
     /**
      An internal SDK call failed with the specified `NSError`.
@@ -92,6 +97,9 @@ public enum CoreStoreError: Error, CustomNSError, Hashable {
             
         case .progressiveMigrationRequired:
             return CoreStoreErrorCode.progressiveMigrationRequired.rawValue
+
+        case .asynchronousMigrationRequired:
+            return CoreStoreErrorCode.asynchronousMigrationRequired.rawValue
             
         case .internalError:
             return CoreStoreErrorCode.internalError.rawValue
@@ -127,6 +135,12 @@ public enum CoreStoreError: Error, CustomNSError, Hashable {
             return [
                 "localStoreURL": localStoreURL
             ]
+
+        case .asynchronousMigrationRequired(let localStoreURL, let nsError):
+            return [
+                "localStoreURL": localStoreURL,
+                "NSError": nsError
+            ]
             
         case .internalError(let nsError):
             return [
@@ -161,6 +175,10 @@ public enum CoreStoreError: Error, CustomNSError, Hashable {
             
         case (.progressiveMigrationRequired(let url1), .progressiveMigrationRequired(let url2)):
             return url1 == url2
+
+        case (.asynchronousMigrationRequired(let url1, let NSError1), .asynchronousMigrationRequired(let url2, let NSError2)):
+            return url1 == url2
+                && NSError1.isEqual(NSError2)
             
         case (.internalError(let NSError1), .internalError(let NSError2)):
             return NSError1.isEqual(NSError2)
@@ -205,6 +223,10 @@ public enum CoreStoreError: Error, CustomNSError, Hashable {
         case .progressiveMigrationRequired(let localStoreURL):
             hasher.combine(localStoreURL)
 
+        case .asynchronousMigrationRequired(let localStoreURL, let nsError):
+            hasher.combine(localStoreURL)
+            hasher.combine(nsError)
+
         case .internalError(let nsError):
             hasher.combine(nsError)
 
@@ -261,6 +283,11 @@ public enum CoreStoreErrorCode: Int {
      Progressive migrations are disabled for a store, but an `NSMappingModel` could not be found for a specific source and destination model versions.
      */
     case progressiveMigrationRequired
+
+    /**
+     The `LocalStorage` was configured with `.allowSynchronousLightweightMigration`, but the model can only be migrated asynchronously.
+     */
+    case asynchronousMigrationRequired
     
     /**
      An internal SDK call failed with the specified "NSError" userInfo key.
diff --git a/Sources/DataStack.swift b/Sources/DataStack.swift
index 8c2b058..78f274d 100644
--- a/Sources/DataStack.swift
+++ b/Sources/DataStack.swift
@@ -345,6 +345,18 @@ public final class DataStack: Equatable {
                     )
                     return storage
                 }
+                catch let error as NSError where storage.localStorageOptions.contains(.allowSynchronousLightweightMigration) && error.isCoreDataMigrationError {
+
+                    let storeError = CoreStoreError.asynchronousMigrationRequired(
+                        localStoreURL: fileURL,
+                        NSError: error
+                    )
+                    CoreStore.log(
+                        storeError,
+                        "Failed to add \(cs_typeName(storage)) to the stack."
+                    )
+                    throw storeError
+                }
             }
             catch {