Add tie breaker for root fetching

Sources/Bookmarks/BookmarkUtils.swift

@@ -25,9 +25,11 @@ public struct BookmarkUtils {
         let request = BookmarkEntity.fetchRequest()
         request.predicate = NSPredicate(format: "%K == %@", #keyPath(BookmarkEntity.uuid), BookmarkEntity.Constants.rootFolderID)
         request.returnsObjectsAsFaults = false
-        request.fetchLimit = 1
 
-        return try? context.fetch(request).first
+        let result = (try? context.fetch(request)) ?? []
+
+        // We cannot use simply sort descriptor as this is to-many on both sides of a relationship.
+        return result.sorted(by: { ($0.children?.count ?? 0) > ($1.children?.count ?? 0) }).first
     }
 
     public static func fetchFavoritesFolders(for displayMode: FavoritesDisplayMode, in context: NSManagedObjectContext) -> [BookmarkEntity] {
@@ -40,9 +42,11 @@ public struct BookmarkUtils {
         let request = BookmarkEntity.fetchRequest()
         request.predicate = NSPredicate(format: "%K == %@", #keyPath(BookmarkEntity.uuid), uuid)
         request.returnsObjectsAsFaults = false
-        request.fetchLimit = 1
 
-        return try? context.fetch(request).first
+        let result = (try? context.fetch(request)) ?? []
+
+        // We cannot use simply sort descriptor as this is to-many on both sides of a relationship.
+        return result.sorted(by: { ($0.favorites?.count ?? 0) > ($1.favorites?.count ?? 0) }).first
     }
 
     public static func fetchFavoritesFolders(withUUIDs uuids: Set<String>, in context: NSManagedObjectContext) -> [BookmarkEntity] {
@@ -51,9 +55,18 @@ public struct BookmarkUtils {
         let request = BookmarkEntity.fetchRequest()
         request.predicate = NSPredicate(format: "%K in %@", #keyPath(BookmarkEntity.uuid), uuids)
         request.returnsObjectsAsFaults = false
-        request.fetchLimit = uuids.count
 
-        return (try? context.fetch(request)) ?? []
+        var objects = (try? context.fetch(request)) ?? []
+        objects.sort(by: { ($0.favorites?.count ?? 0) > ($1.favorites?.count ?? 0) })
+
+        var result = [BookmarkEntity]()
+        for uuid in uuids {
+            if let entity = objects.first(where: { $0.uuid == uuid }) {
+                result.append(entity)
+            }
+        }
+
+        return result
     }
 
     public static func fetchOrphanedEntities(_ context: NSManagedObjectContext) -> [BookmarkEntity] {

Tests/BookmarksTests/BookmarkUtilsTests.swift

@@ -48,6 +48,77 @@ final class BookmarkUtilsTests: XCTestCase {
         try? FileManager.default.removeItem(at: location)
     }
 
+    func testThatFetchingRootFolderPicksTheOneWithMostChildren() {
+        let context = bookmarksDatabase.makeContext(concurrencyType: .privateQueueConcurrencyType)
+        context.performAndWait {
+            BookmarkUtils.prepareFoldersStructure(in: context)
+            try! context.save()
+
+            guard let root1 = BookmarkUtils.fetchRootFolder(context) else {
+                XCTFail("root required")
+                return
+            }
+
+            let root2 = BookmarkEntity.makeFolder(title: root1.title!, parent: root1, context: context)
+            root2.uuid = root1.uuid
+            root2.parent = nil
+
+            let root3 = BookmarkEntity.makeFolder(title: root1.title!, parent: root1, context: context)
+            root3.uuid = root1.uuid
+            root3.parent = nil
+
+            _ = BookmarkEntity.makeBookmark(title: "a", url: "a", parent: root2, context: context)
+            _ = BookmarkEntity.makeBookmark(title: "b", url: "b", parent: root2, context: context)
+            _ = BookmarkEntity.makeBookmark(title: "c", url: "c", parent: root1, context: context)
+
+            try! context.save()
+
+            let root = BookmarkUtils.fetchRootFolder(context)
+            XCTAssertEqual(root, root2)
+        }
+    }
+
+    func testThatFetchingRootFavoritesFolderPicksTheOneWithMostFavorites() {
+        let context = bookmarksDatabase.makeContext(concurrencyType: .privateQueueConcurrencyType)
+        context.performAndWait {
+            BookmarkUtils.prepareFoldersStructure(in: context)
+            try! context.save()
+
+            guard let root = BookmarkUtils.fetchRootFolder(context),
+                let mobileFav1 = BookmarkUtils.fetchFavoritesFolder(withUUID: FavoritesFolderID.mobile.rawValue, in: context),
+                  let unifiedFav1 = BookmarkUtils.fetchFavoritesFolder(withUUID: FavoritesFolderID.unified.rawValue, in: context) else {
+                XCTFail("root required")
+                return
+            }
+
+            let mobileFav2 = BookmarkEntity.makeFolder(title: mobileFav1.title!, parent: root, context: context)
+            mobileFav2.uuid = mobileFav1.uuid
+            mobileFav2.parent = nil
+
+            let unifiedFav2 = BookmarkEntity.makeFolder(title: unifiedFav1.title!, parent: root, context: context)
+            unifiedFav2.uuid = unifiedFav1.uuid
+            unifiedFav2.parent = nil
+
+            let bA = BookmarkEntity.makeBookmark(title: "a", url: "a", parent: root, context: context)
+            let bB = BookmarkEntity.makeBookmark(title: "b", url: "b", parent: root, context: context)
+
+            bA.addToFavorites(favoritesRoot: mobileFav2)
+            bA.addToFavorites(favoritesRoot: unifiedFav1)
+            bB.addToFavorites(folders: [mobileFav2, unifiedFav1])
+
+            try! context.save()
+
+            let roots = BookmarkUtils.fetchFavoritesFolders(for: .displayUnified(native: .mobile), in: context)
+            XCTAssertEqual(Set(roots.map { $0.uuid }), [mobileFav2.uuid, unifiedFav1.uuid])
+
+            let mobileFav = BookmarkUtils.fetchFavoritesFolder(withUUID: FavoritesFolderID.mobile.rawValue, in: context)
+            XCTAssertEqual(mobileFav, mobileFav2)
+
+            let unifiedFav = BookmarkUtils.fetchFavoritesFolder(withUUID: FavoritesFolderID.unified.rawValue, in: context)
+            XCTAssertEqual(unifiedFav, unifiedFav1)
+        }
+    }
+
     func testCopyFavoritesWhenDisablingSyncInDisplayNativeMode() async throws {
 
         let context = bookmarksDatabase.makeContext(concurrencyType: .privateQueueConcurrencyType)