Fix invalid states from triggers

Examples/Examples.xcodeproj/project.pbxproj

@@ -9,6 +9,8 @@
 /* Begin PBXBuildFile section */
 		C441694F2F38F3B100051412 /* SQLiteUndo in Frameworks */ = {isa = PBXBuildFile; productRef = C441694E2F38F3B100051412 /* SQLiteUndo */; };
 		C44169512F38F3B100051412 /* SQLiteUndoTCA in Frameworks */ = {isa = PBXBuildFile; productRef = C44169502F38F3B100051412 /* SQLiteUndoTCA */; };
+		C45245EF2F3D353800F31BB8 /* SQLiteUndo in Frameworks */ = {isa = PBXBuildFile; productRef = C45245EE2F3D353800F31BB8 /* SQLiteUndo */; };
+		C45245F12F3D353800F31BB8 /* SQLiteUndoTCA in Frameworks */ = {isa = PBXBuildFile; productRef = C45245F02F3D353800F31BB8 /* SQLiteUndoTCA */; };
 		C4B1976A2F33B52B001EAFC2 /* SQLiteUndo in Frameworks */ = {isa = PBXBuildFile; productRef = C4B197692F33B52B001EAFC2 /* SQLiteUndo */; };
 		C4B197712F33B5D9001EAFC2 /* ComposableArchitecture in Frameworks */ = {isa = PBXBuildFile; productRef = C4B197702F33B5D9001EAFC2 /* ComposableArchitecture */; };
 		C4B197F02F33C28A001EAFC2 /* SQLiteUndo in Frameworks */ = {isa = PBXBuildFile; productRef = C4B197EF2F33C28A001EAFC2 /* SQLiteUndo */; };
@@ -35,11 +37,13 @@
 			buildActionMask = 2147483647;
 			files = (
 				C441694F2F38F3B100051412 /* SQLiteUndo in Frameworks */,
+				C45245EF2F3D353800F31BB8 /* SQLiteUndo in Frameworks */,
 				C4B197712F33B5D9001EAFC2 /* ComposableArchitecture in Frameworks */,
 				C4B197F22F33C28A001EAFC2 /* SQLiteUndoTCA in Frameworks */,
 				C4B197F52F33C2B0001EAFC2 /* SQLiteUndo in Frameworks */,
 				C4B197F02F33C28A001EAFC2 /* SQLiteUndo in Frameworks */,
 				C44169512F38F3B100051412 /* SQLiteUndoTCA in Frameworks */,
+				C45245F12F3D353800F31BB8 /* SQLiteUndoTCA in Frameworks */,
 				C4B1976A2F33B52B001EAFC2 /* SQLiteUndo in Frameworks */,
 				C4B197F72F33C2B0001EAFC2 /* SQLiteUndoTCA in Frameworks */,
 			);
@@ -92,6 +96,8 @@
 				C4B197F62F33C2B0001EAFC2 /* SQLiteUndoTCA */,
 				C441694E2F38F3B100051412 /* SQLiteUndo */,
 				C44169502F38F3B100051412 /* SQLiteUndoTCA */,
+				C45245EE2F3D353800F31BB8 /* SQLiteUndo */,
+				C45245F02F3D353800F31BB8 /* SQLiteUndoTCA */,
 			);
 			productName = UndoForMacOS;
 			productReference = C4B1975D2F33B502001EAFC2 /* UndoForMacOS.app */;
@@ -123,7 +129,7 @@
 			minimizedProjectReferenceProxies = 1;
 			packageReferences = (
 				C4B1976F2F33B5D9001EAFC2 /* XCRemoteSwiftPackageReference "swift-composable-architecture" */,
-				C441694D2F38F3B100051412 /* XCLocalSwiftPackageReference "../../sqlite-undo" */,
+				C45245ED2F3D353800F31BB8 /* XCLocalSwiftPackageReference "../../sqlite-undo" */,
 			);
 			preferredProjectObjectVersion = 77;
 			productRefGroup = C4B197462F33B4B4001EAFC2 /* Products */;
@@ -364,7 +370,7 @@
 /* End XCConfigurationList section */
 
 /* Begin XCLocalSwiftPackageReference section */
-		C441694D2F38F3B100051412 /* XCLocalSwiftPackageReference "../../sqlite-undo" */ = {
+		C45245ED2F3D353800F31BB8 /* XCLocalSwiftPackageReference "../../sqlite-undo" */ = {
 			isa = XCLocalSwiftPackageReference;
 			relativePath = "../../sqlite-undo";
 		};
@@ -390,6 +396,14 @@
 			isa = XCSwiftPackageProductDependency;
 			productName = SQLiteUndoTCA;
 		};
+		C45245EE2F3D353800F31BB8 /* SQLiteUndo */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = SQLiteUndo;
+		};
+		C45245F02F3D353800F31BB8 /* SQLiteUndoTCA */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = SQLiteUndoTCA;
+		};
 		C4B197692F33B52B001EAFC2 /* SQLiteUndo */ = {
 			isa = XCSwiftPackageProductDependency;
 			productName = SQLiteUndo;

Examples/UndoForMacOS/UndoForMacOSApp.swift

@@ -38,6 +38,7 @@ struct DemoFeature {
     case undoManager(UndoManagingAction)
     case addItem
     case addItemInBackground
+    case addItemWithoutTracking
     case addUntrackedItem
     case incrementCount(Int)
     case incrementAll
@@ -75,6 +76,17 @@ struct DemoFeature {
           }
         }
 
+      case .addItemWithoutTracking:
+        withErrorReporting {
+          try withUndoDisabled {
+            try database.write { db in
+              let nextID = (try DemoItem.all.fetchAll(db).map(\.id).max() ?? 0) + 1
+              try DemoItem.insert { DemoItem(id: nextID, name: "Item \(nextID)") }.execute(db)
+            }
+          }
+        }
+        return .none
+
       case .addUntrackedItem:
         withErrorReporting {
           try undoable("Add Untracked Item") {
@@ -161,25 +173,33 @@ struct DemoView: View {
       }
       .frame(minHeight: 200)
 
-      HStack {
-        Button("Add Item") {
-          store.send(.addItem)
-        }
-        .buttonStyle(.borderedProminent)
-        Button("Add Item (Background)") {
-          store.send(.addItemInBackground)
-        }
-        .buttonStyle(.bordered)
-        Button("Increment All") {
-          store.send(.incrementAll)
+      VStack {
+        HStack {
+          Button("Add Item") {
+            store.send(.addItem)
+          }
+          .buttonStyle(.borderedProminent)
+          Button("Increment All") {
+            store.send(.incrementAll)
+          }
+          .buttonStyle(.bordered)
+          .disabled(store.items.isEmpty)
         }
-        .buttonStyle(.bordered)
-        .disabled(store.items.isEmpty)
-        Divider()
-        Button("Add Untracked Item") {
-          store.send(.addUntrackedItem)
+        HStack {
+          Button("Add Item without tracking") {
+            store.send(.addItemWithoutTracking)
+          }
+          .buttonStyle(.bordered)
+          Button("Add Item (Background)") {
+            store.send(.addItemInBackground)
+          }
+          .buttonStyle(.bordered)
+          Button("Add Untracked Item") {
+            store.send(.addUntrackedItem)
+          }
+          .buttonStyle(.bordered)
         }
-        .buttonStyle(.bordered)
+        .fixedSize()
       }
     }
     .padding()

README.md

@@ -2,7 +2,28 @@
 
 [![CI](https://github.com/latentco/sqlite-undo/actions/workflows/ci.yml/badge.svg)](https://github.com/latentco/sqlite-undo/actions/workflows/ci.yml)
 
-SQLite-based undo/redo for Swift apps using [SQLiteData](https://github.com/pointfreeco/sqlite-data). Uses database triggers to capture changes automatically using the pattern described in [Automatic Undo/Redo Using SQLite](https://www.sqlite.org/undoredo.html)
+SQLite-based undo/redo for Swift apps using [SQLiteData](https://github.com/pointfreeco/sqlite-data) and [StructuredQueries](https://github.com/pointfreeco/swift-structured-queries). Uses database triggers to automatically capture reverse SQL for all changes to tracked tables, following the pattern described in [Automatic Undo/Redo Using SQLite](https://www.sqlite.org/undoredo.html).
+
+Changes are grouped into barriers that represent single user actions (e.g., "Set Rating", "Delete Item"). Barriers integrate with `NSUndoManager` so undo/redo works with the standard Edit menu, keyboard shortcuts, and shake-to-undo.
+
+Two libraries are provided:
+
+- **SQLiteUndo** — core undo engine, barriers, and free functions (`undoable`, `withUndoDisabled`)
+- **SQLiteUndoTCA** — [ComposableArchitecture](https://github.com/pointfreeco/swift-composable-architecture) integration for `UndoManager` wiring in SwiftUI
+
+## Adding SQLiteUndo as a dependency
+
+Add the following to your `Package.swift`:
+
+```swift
+.package(url: "https://github.com/latentco/sqlite-undo.git", from: "0.1.0"),
+```
+
+Then add the product to your target's dependencies:
+
+```swift
+.product(name: "SQLiteUndo", package: "sqlite-undo"),
+```
 
 ## Setup
 
@@ -38,6 +59,49 @@ try await undoable("Set Rating") {
 }
 ```
 
+### Disabling undo tracking
+
+Use `withUndoDisabled` for operations that shouldn't be undoable (e.g., batch imports, programmatic state rebuilds):
+
+```swift
+try withUndoDisabled {
+  try database.write { db in
+    try Article.insert { Article(id: 1, name: "Imported") }.execute(db)
+  }
+}
+```
+
+### Application triggers
+
+If your app has triggers that cascade writes (e.g., clearing a flag on other rows, updating derived state), they **must** include `UndoEngine.isReplaying()` in their WHEN clause:
+
+```swift
+Article.createTemporaryTrigger(
+  after: .update { $0.isPrimary },
+  forEachRow: { old, new in
+    // Clear isPrimary on all other rows
+    Article.where { $0.id != new.id }
+      .update { $0.isPrimary = false }
+  },
+  when: { old, new in
+    !UndoEngine.isReplaying()
+  }
+)
+```
+
+Or in raw SQL:
+
+```sql
+CREATE TRIGGER clear_primary
+AFTER UPDATE OF "isPrimary" ON "articles"
+WHEN NOT "sqliteundo_isReplaying"()
+BEGIN
+  UPDATE "articles" SET "isPrimary" = 0 WHERE "id" != NEW."id";
+END
+```
+
+> **Note:** The undo system uses BEFORE triggers to capture original values and records all effects of a change (including cascades) in the undo log. During undo/redo replay, each effect is replayed individually, so cascade triggers must be suppressed to avoid corrupting the restored state. Without the `isReplaying` guard, a cascade trigger would fire again during replay and overwrite values that the undo system is trying to restore.
+
 ### With explicit barrier management
 
 ```swift

Sources/SQLiteUndo/UndoCoordinator.swift

@@ -94,7 +94,7 @@ final class UndoCoordinator: Sendable {
       return nil
     }
 
-    return try database.read { db in
+    return try database.write { db in
       guard let endSeq = try db.undoLogMaxSeq(), endSeq >= openBarrier.startSeq else {
         let tables = registeredTables.sorted()
         logger.warning(
@@ -110,6 +110,14 @@ final class UndoCoordinator: Sendable {
         return nil
       }
 
+      // Reconcile duplicate entries from cascading BEFORE triggers
+      try db.reconcileUndoLogEntries(from: openBarrier.startSeq, to: endSeq)
+
+      // Re-read endSeq since reconciliation may have removed entries
+      guard let endSeq = try db.undoLogMaxSeq(), endSeq >= openBarrier.startSeq else {
+        return nil
+      }
+
       let barrier = UndoBarrier(
         id: id,
         name: openBarrier.name,
@@ -215,20 +223,4 @@ final class UndoCoordinator: Sendable {
       }
     }
   }
-
-  /// Temporarily disable undo tracking.
-  ///
-  /// Use this for bulk operations, migrations, or imports where you don't
-  /// want individual changes tracked.
-  func withUndoDisabled<T>(_ operation: () throws -> T) throws -> T {
-    try database.write { db in
-      try UndoState.find(1).update { $0.isActive = false }.execute(db)
-    }
-    defer {
-      try? database.write { db in
-        try UndoState.find(1).update { $0.isActive = true }.execute(db)
-      }
-    }
-    return try operation()
-  }
 }

Sources/SQLiteUndo/UndoEngine.swift

@@ -19,29 +19,30 @@ private let logger = Logger(subsystem: "SQLiteUndo", category: "UndoEngine")
 ///   $0.defaultUndoStack = .live(windowUndoManager)
 ///   $0.defaultUndoEngine = try! UndoEngine(
 ///     for: $0.defaultDatabase,
-///     tables: ProjectItem.self, ProjectEdit.self
+///     tables: Item.self, Edit.self
 ///   )
 /// }
 /// ```
 ///
 /// ## Usage
 ///
+/// Wrap database changes in ``undoable(_:operation:)-3cgh0`` to make them undoable:
+///
 /// ```swift
-/// @Dependency(\.defaultUndoEngine) var undoEngine
+/// try undoable("Set Rating") {
+///   try database.write { db in
+///     try Item.find(id).update { $0.rating = rating }.execute(db)
+///   }
+/// }
+/// ```
 ///
-/// // Simple operation
-/// let barrierId = try undoEngine.beginBarrier("Set Rating")
-/// try database.write { /* make changes */ }
-/// try undoEngine.endBarrier(barrierId)
+/// Use ``withUndoDisabled(_:)`` for operations that shouldn't be tracked:
 ///
-/// // With error handling
-/// do {
-///   let barrierId = try undoEngine.beginBarrier("Set Rating")
-///   try database.write { /* make changes */ }
-///   try undoEngine.endBarrier(barrierId)
-/// } catch {
-///   try undoEngine.cancelBarrier(barrierId)
-///   throw error
+/// ```swift
+/// try withUndoDisabled {
+///   try database.write { db in
+///     try Item.insert { Item(id: 1, name: "Imported") }.execute(db)
+///   }
 /// }
 /// ```
 @DependencyClient
@@ -65,15 +66,41 @@ public struct UndoEngine: Sendable {
   ///
   /// - Parameter id: The barrier ID from `beginBarrier`
   public var cancelBarrier: @Sendable (_ id: UUID) throws -> Void
+}
+
+/// Whether undo tracking is active. Default true; set false inside `withUndoDisabled`.
+@TaskLocal var _undoIsActive = true
+
+/// Whether the undo system is replaying entries (undo/redo in progress).
+@TaskLocal var _undoIsReplaying = false
+
+@DatabaseFunction("sqliteundo_isActive")
+func undoIsActiveFunction() -> Bool {
+  _undoIsActive
+}
 
-  /// Temporarily disable undo tracking for an operation.
+@DatabaseFunction("sqliteundo_isReplaying")
+func undoIsReplayingFunction() -> Bool {
+  _undoIsReplaying
+}
+
+extension UndoEngine {
+  /// A SQL expression that evaluates to true when the undo system is replaying entries.
   ///
-  /// Use for migrations, bulk imports, or other operations that shouldn't
-  /// be individually undoable.
+  /// Use `!UndoEngine.isReplaying()` in application trigger WHEN clauses to suppress
+  /// cascading writes during undo/redo replay:
   ///
-  /// - Parameter operation: The operation to perform without tracking
-  public var withUndoDisabled: @Sendable (_ operation: () throws -> Void) throws -> Void = {
-    try $0()
+  /// ```swift
+  /// Table.createTemporaryTrigger(
+  ///   after: .update { $0.isSelected }
+  ///   forEachRow: { old, new in ... }
+  ///   when: { old, new in
+  ///     someCondition.and(!UndoEngine.isReplaying())
+  ///   }
+  /// )
+  /// ```
+  public static func isReplaying() -> some QueryExpression<Bool> {
+    $undoIsReplayingFunction()
   }
 }
 
@@ -104,7 +131,10 @@ extension UndoEngine {
     let registeredNames = Set(tables.map { $0.tableName })
     let untrackedNames = Set(untracked.map { $0.tableName })
     self = .make(
-      database: database, registeredTables: registeredNames, untrackedTables: untrackedNames)
+      database: database,
+      registeredTables: registeredNames,
+      untrackedTables: untrackedNames
+    )
   }
 
   /// Create an UndoEngine for a database with the specified tracked tables.
@@ -126,7 +156,10 @@ extension UndoEngine {
     let registeredNames = Set(tables.map { $0.tableName })
     let untrackedNames = Set(untracked.map { $0.tableName })
     self = .make(
-      database: database, registeredTables: registeredNames, untrackedTables: untrackedNames)
+      database: database,
+      registeredTables: registeredNames,
+      untrackedTables: untrackedNames
+    )
   }
 
   private static func install(for database: any DatabaseWriter, tables: [any Table.Type])
@@ -191,9 +224,6 @@ extension UndoEngine: DependencyKey {
       },
       cancelBarrier: { id in
         try coordinator.cancelBarrier(id)
-      },
-      withUndoDisabled: { operation in
-        try coordinator.withUndoDisabled(operation)
       }
     )
   }