Fix CloudKit data loss on delete-then-reinsert

Sources/SQLiteData/CloudKit/Internal/MockSyncEngine.swift

@@ -136,12 +136,12 @@
   package final class MockSyncEngineState: CKSyncEngineStateProtocol {
     package let changeTag = LockIsolated(0)
     package let _pendingRecordZoneChanges = LockIsolated<
-      OrderedSet<CKSyncEngine.PendingRecordZoneChange>
-    >([]
+      OrderedDictionary<CKRecord.ID, CKSyncEngine.PendingRecordZoneChange>
+    >([:]
     )
     package let _pendingDatabaseChanges = LockIsolated<
-      OrderedSet<CKSyncEngine.PendingDatabaseChange>
-    >([])
+      OrderedDictionary<CKRecordZone.ID, CKSyncEngine.PendingDatabaseChange>
+    >([:])
     private let fileID: StaticString
     private let filePath: StaticString
     private let line: UInt
@@ -160,11 +160,11 @@
     }
 
     package var pendingRecordZoneChanges: [CKSyncEngine.PendingRecordZoneChange] {
-      _pendingRecordZoneChanges.withValue { Array($0) }
+      _pendingRecordZoneChanges.withValue { Array($0.values) }
     }
 
     package var pendingDatabaseChanges: [CKSyncEngine.PendingDatabaseChange] {
-      _pendingDatabaseChanges.withValue { Array($0) }
+      _pendingDatabaseChanges.withValue { Array($0.values) }
     }
 
     package func removePendingChanges() {
@@ -173,26 +173,58 @@
     }
 
     package func add(pendingRecordZoneChanges: [CKSyncEngine.PendingRecordZoneChange]) {
-      self._pendingRecordZoneChanges.withValue {
-        $0.append(contentsOf: pendingRecordZoneChanges)
+      self._pendingRecordZoneChanges.withValue { dict in
+        for change in pendingRecordZoneChanges {
+          switch change {
+          case .saveRecord(let id), .deleteRecord(let id):
+            dict.updateValue(change, forKey: id)
+          @unknown default:
+            fatalError("Unsupported pendingRecordZoneChange: \(change)")
+          }
+        }
       }
     }
 
     package func remove(pendingRecordZoneChanges: [CKSyncEngine.PendingRecordZoneChange]) {
-      self._pendingRecordZoneChanges.withValue {
-        $0.subtract(pendingRecordZoneChanges)
+      self._pendingRecordZoneChanges.withValue { dict in
+        for change in pendingRecordZoneChanges {
+          switch change {
+          case .saveRecord(let id), .deleteRecord(let id):
+            if dict[id] == change { dict.removeValue(forKey: id) }
+          @unknown default:
+            fatalError("Unsupported pendingRecordZoneChange: \(change)")
+          }
+        }
       }
     }
 
     package func add(pendingDatabaseChanges: [CKSyncEngine.PendingDatabaseChange]) {
-      self._pendingDatabaseChanges.withValue {
-        $0.append(contentsOf: pendingDatabaseChanges)
+      self._pendingDatabaseChanges.withValue { dict in
+        for change in pendingDatabaseChanges {
+          switch change {
+          case .saveZone(let zone):
+            dict.updateValue(change, forKey: zone.zoneID)
+          case .deleteZone(let zoneID):
+            dict.updateValue(change, forKey: zoneID)
+          @unknown default:
+            fatalError("Unsupported pendingDatabaseChange: \(change)")
+          }
+        }
       }
     }
 
     package func remove(pendingDatabaseChanges: [CKSyncEngine.PendingDatabaseChange]) {
-      self._pendingDatabaseChanges.withValue {
-        $0.subtract(pendingDatabaseChanges)
+      self._pendingDatabaseChanges.withValue { dict in
+        for change in pendingDatabaseChanges {
+          switch change {
+          case .saveZone(let zone):
+            if dict[zone.zoneID] == change { dict.removeValue(forKey: zone.zoneID) }
+          case .deleteZone(let zoneID):
+            if dict[zoneID] == change { dict.removeValue(forKey: zoneID) }
+          @unknown default:
+            fatalError("Unsupported pendingDatabaseChange: \(change)")
+          }
+        }
       }
     }
   }

Sources/SQLiteData/CloudKit/Internal/Triggers.swift

@@ -82,6 +82,16 @@
             defaultZone: defaultZone,
             privateTables: privateTables
           )
+          SyncMetadata
+            .where {
+              $0.recordPrimaryKey.eq(#sql("\(new.primaryKey)"))
+                && $0.recordType.eq(tableName)
+                && $0._isDeleted
+            }
+            .update {
+              $0._isDeleted = false
+              $0.userModificationTime = $currentTime()
+            }
         }
       )
     }
@@ -242,6 +252,7 @@
         afterZoneUpdateTrigger(),
         afterUpdateTrigger(for: syncEngine),
         afterSoftDeleteTrigger(for: syncEngine),
+        afterUndeleteTrigger(for: syncEngine),
       ]
     }
 
@@ -348,6 +359,29 @@
         }
       )
     }
+
+    fileprivate static func afterUndeleteTrigger(
+      for syncEngine: SyncEngine
+    ) -> TemporaryTrigger<Self> {
+      createTemporaryTrigger(
+        "\(String.sqliteDataCloudKitSchemaName)_after_undelete_on_sqlitedata_icloud_metadata",
+        ifNotExists: true,
+        after: .update(of: \._isDeleted) { _, new in
+          Values(
+            syncEngine.$didUpdate(
+              recordName: new.recordName,
+              zoneName: new.zoneName,
+              ownerName: new.ownerName,
+              oldZoneName: new.zoneName,
+              oldOwnerName: new.ownerName,
+              descendantRecordNames: #bind(nil)
+            )
+          )
+        } when: { old, new in
+          old._isDeleted && !new._isDeleted && !SyncEngine.$isSynchronizing
+        }
+      )
+    }
   }
 
   @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)