Use a test database for library tests

Tests/DatabaseTests.swift

@@ -0,0 +1,103 @@
+// This file is part of Kiwix for iOS & macOS.
+//
+// Kiwix is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// any later version.
+//
+// Kiwix is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Kiwix; If not, see https://www.gnu.org/licenses/.
+
+import XCTest
+@testable import Kiwix
+
+// swiftlint:disable force_try
+final class DatabaseTests: XCTestCase {
+
+    /// Make sure our test database behaves the same way as the real one
+    func xtestDatabases() throws {
+        let database: Databasing = Database.shared
+        let testDB = TestDatabase()
+        
+        // insertion
+        let id1 = UUID()
+        let id2 = UUID()
+        
+        var zimFileIDs = Set([id1, id2])
+        let insertCount = try database.context.bulkInsert { zimFile in
+            while !zimFileIDs.isEmpty {
+                guard let id = zimFileIDs.popFirst() else { continue }
+                let metadata = Self.metadata(for: id)
+                LibraryOperations.configureZimFile(zimFile, metadata: metadata)
+                return false
+            }
+            return true
+        }
+    
+        var uuids = Set([id1, id2])
+        let testInsertCount = try testDB.context.bulkInsert { zimFile in
+            while !uuids.isEmpty {
+                guard let id = uuids.popFirst() else { continue }
+                let metadata = Self.metadata(for: id)
+                LibraryOperations.configureZimFile(zimFile, metadata: metadata)
+                return false
+            }
+            return true
+        }
+        
+        XCTAssertEqual(insertCount, testInsertCount)
+        
+        // test fetching
+        let zimFiles = try! database.context.fetchZimFiles()
+        XCTAssertEqual(zimFiles.count, 2)
+        XCTAssertEqual(try! testDB.context.fetchZimFiles().count, 2)
+    
+        // test deletion
+        let noDeleteCount = try! database.context.bulkDeleteNotDownloadedZims(notIncludedIn: [id1, id2])
+        let testNoDeleteCount = try! testDB.context.bulkDeleteNotDownloadedZims(notIncludedIn: [id1, id2])
+        
+        XCTAssertEqual(noDeleteCount, 0)
+        XCTAssertEqual(testNoDeleteCount, 0)
+        
+        let deleteCount = try! database.context.bulkDeleteNotDownloadedZims(notIncludedIn: [])
+        let testDeleteCount = try! testDB.context.bulkDeleteNotDownloadedZims(notIncludedIn: [])
+        
+        XCTAssertEqual(deleteCount, 2)
+        XCTAssertEqual(testDeleteCount, 2)
+        
+        XCTAssertEqual(try! database.context.fetchZimFiles().count, 0)
+        XCTAssertEqual(try! testDB.context.fetchZimFiles().count, 0)
+        
+    }
+    
+    private static func metadata(for uuid: UUID) -> ZimFileMetaData {
+        ZimFileMetaData(
+            fileID: uuid,
+            groupIdentifier: "group",
+            title: "test-title",
+            fileDescription: "desc",
+            languageCodes: "en",
+            category: "meta",
+            creationDate: .now,
+            size: 11,
+            articleCount: 1,
+            mediaCount: 1,
+            creator: "me",
+            publisher: "me",
+            downloadURL: nil,
+            faviconURL: nil,
+            faviconData: nil,
+            flavor: nil,
+            hasDetails: false,
+            hasPictures: false,
+            hasVideos: false,
+            requiresServiceWorkers: false
+        )
+    }
+}
+// swiftlint:enable force_try

Tests/LibraryRefreshViewModelTest.swift

@@ -109,7 +109,8 @@ final class LibraryRefreshViewModelTest: XCTestCase {
         let viewModel = LibraryViewModel(urlSession: urlSession,
                                          processFactory: { LibraryProcess(defaultState: .initial) },
                                          defaults: testDefaults,
-                                         categories: CategoriesToLanguages(withDefaults: testDefaults))
+                                         categories: CategoriesToLanguages(withDefaults: testDefaults),
+                                         database: TestDatabase())
         await viewModel.start(isUserInitiated: true)
         XCTAssert(viewModel.error is LibraryRefreshError)
         XCTAssertEqual(
@@ -135,7 +136,8 @@ final class LibraryRefreshViewModelTest: XCTestCase {
         let viewModel = LibraryViewModel(urlSession: urlSession,
                                          processFactory: { LibraryProcess(defaultState: .initial) },
                                          defaults: testDefaults,
-                                         categories: CategoriesToLanguages(withDefaults: testDefaults))
+                                         categories: CategoriesToLanguages(withDefaults: testDefaults),
+                                         database: TestDatabase())
         await viewModel.start(isUserInitiated: true)
         XCTAssert(viewModel.error is LibraryRefreshError)
         XCTAssertEqual(
@@ -162,7 +164,8 @@ final class LibraryRefreshViewModelTest: XCTestCase {
         let viewModel = LibraryViewModel(urlSession: urlSession,
                                          processFactory: { LibraryProcess(defaultState: .initial) },
                                          defaults: testDefaults,
-                                         categories: CategoriesToLanguages(withDefaults: testDefaults))
+                                         categories: CategoriesToLanguages(withDefaults: testDefaults),
+                                         database: TestDatabase())
         await viewModel.start(isUserInitiated: true)
         XCTExpectFailure("Requires work in dependency to resolve the issue.")
         XCTAssertEqual(
@@ -189,23 +192,28 @@ final class LibraryRefreshViewModelTest: XCTestCase {
         }
         let testDefaults = TestDefaults()
         testDefaults.setup()
+        let database = TestDatabase()
+        let context = database.context
+        
         let viewModel = LibraryViewModel(urlSession: urlSession,
                                          processFactory: { LibraryProcess(defaultState: .initial) },
                                          defaults: testDefaults,
-                                         categories: CategoriesToLanguages(withDefaults: testDefaults))
+                                         categories: CategoriesToLanguages(withDefaults: testDefaults),
+                                         database: database)
+        
         await viewModel.start(isUserInitiated: true)
 
         // check no error has happened
         XCTAssertNil(viewModel.error)
 
         // check one zim file is in the database
-        let context = Database.shared.viewContext
-        let zimFiles = try context.fetch(ZimFile.fetchRequest())
+        let zimFiles = try context.fetchZimFiles()
         XCTAssertEqual(zimFiles.count, 1)
         XCTAssertEqual(zimFiles[0].id, zimFileID)
 
         // check zim file can be retrieved by id, and properties are populated
-        let zimFile = try XCTUnwrap(try context.fetch(ZimFile.fetchRequest(fileID: zimFileID)).first)
+        // swiftlint:disable:next force_try
+        let zimFile = try! XCTUnwrap(zimFiles.first { $0.fileID == zimFileID })
         XCTAssertEqual(zimFile.id, zimFileID)
         XCTAssertEqual(zimFile.articleCount, 50001)
         XCTAssertEqual(zimFile.category, Category.wikipedia.rawValue)
@@ -237,8 +245,6 @@ final class LibraryRefreshViewModelTest: XCTestCase {
         XCTAssertEqual(zimFile.requiresServiceWorkers, false)
         XCTAssertEqual(zimFile.size, 6515656704)
         
-        // clean up
-        context.delete(zimFile)
     }
 
     /// Test zim file deprecation
@@ -246,21 +252,43 @@ final class LibraryRefreshViewModelTest: XCTestCase {
     func testZimFileDeprecation() async throws {
         let testDefaults = TestDefaults()
         testDefaults.setup()
-        let context = Database.shared.viewContext
-        let oldZimFiles = try? context.fetch(ZimFile.fetchRequest())
-        oldZimFiles?.forEach { zimFile in
-            context.delete(zimFile)
-        }
-        if context.hasChanges {
-            try? context.save()
-        }
+        
+        let database = TestDatabase()
+        let context = database.context
         
         // refresh library for the first time, which should create one zim file
         let viewModel = LibraryViewModel(urlSession: urlSession,
                                          processFactory: { LibraryProcess(defaultState: .initial) },
                                          defaults: testDefaults,
-                                         categories: CategoriesToLanguages(withDefaults: testDefaults))
+                                         categories: CategoriesToLanguages(withDefaults: testDefaults),
+                                         database: database)
         
+        await forceRefresh(viewModel: viewModel)
+        
+        let zimFile1 = try XCTUnwrap(try context.fetchZimFiles().first)
+
+        // refresh library for the second time, which should replace the old zim file with a new one
+        await forceRefresh(viewModel: viewModel)
+        
+        var zimFiles = try context.fetchZimFiles()
+        XCTAssertEqual(zimFiles.count, 1)
+        let zimFile2 = try XCTUnwrap(zimFiles.first)
+        XCTAssertNotEqual(zimFile1.fileID, zimFile2.fileID)
+
+        // set fileURLBookmark of zim file 2
+        zimFile2.fileURLBookmark = Data("/Users/tester/Downloads/file_url.zim".utf8)
+
+        // refresh library for the third time
+        await forceRefresh(viewModel: viewModel)
+        
+        zimFiles = try context.fetchZimFiles()
+
+        // check there are two zim files in the database, and zim file 2 is not deprecated
+        XCTAssertEqual(zimFiles.count, 2)
+        XCTAssertEqual(zimFiles.filter({ $0.fileID == zimFile2.fileID }).count, 1)
+    }
+    
+    private func forceRefresh(viewModel: LibraryViewModel) async {
         let expectationVMComplete = XCTestExpectation(description: "viewModel completed")
         viewModel.$state.sink { value in
             switch value {
@@ -272,44 +300,6 @@ final class LibraryRefreshViewModelTest: XCTestCase {
         }.store(in: &cancellables)
         await viewModel.start(isUserInitiated: true)
         await fulfillment(of: [expectationVMComplete], timeout: 2)
-        
-        let zimFile1 = try XCTUnwrap(try context.fetch(ZimFile.fetchRequest()).first)
-
-        // refresh library for the second time, which should replace the old zim file with a new one
-        let expectationVMComplete2 = XCTestExpectation(description: "viewModel completed")
-        viewModel.$state.sink { value in
-            switch value {
-            case .complete:
-                expectationVMComplete2.fulfill()
-            default:
-                break
-            }
-        }.store(in: &cancellables)
-        await viewModel.start(isUserInitiated: true)
-        await fulfillment(of: [expectationVMComplete2], timeout: 2)
-        
-        var zimFiles = try context.fetch(ZimFile.fetchRequest())
-        XCTAssertEqual(zimFiles.count, 1)
-        let zimFile2 = try XCTUnwrap(zimFiles.first)
-        XCTAssertNotEqual(zimFile1.fileID, zimFile2.fileID)
-
-        // set fileURLBookmark of zim file 2
-        zimFile2.fileURLBookmark = Data("/Users/tester/Downloads/file_url.zim".utf8)
-        try context.save()
-
-        // refresh library for the third time
-        await viewModel.start(isUserInitiated: true)
-        zimFiles = try context.fetch(ZimFile.fetchRequest())
-
-        // check there are two zim files in the database, and zim file 2 is not deprecated
-        XCTAssertEqual(zimFiles.count, 2)
-        XCTAssertEqual(zimFiles.filter({ $0.fileID == zimFile2.fileID }).count, 1)
-        
-        // clean up
-        context.delete(zimFile1)
-        context.delete(zimFile2)
-        
-        try? context.save()
     }
 }
 

Tests/TestDatabase.swift

@@ -0,0 +1,59 @@
+// This file is part of Kiwix for iOS & macOS.
+//
+// Kiwix is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// any later version.
+//
+// Kiwix is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Kiwix; If not, see https://www.gnu.org/licenses/.
+
+import Foundation
+import CoreData
+@testable import Kiwix
+
+final class TestContext: DBObjectContext {
+    
+    private let objectContext = NSManagedObjectContext(.privateQueue)
+    
+    var zimFiles: [ZimFile] = []
+    
+    func fetchZimFiles() throws -> [ZimFile] {
+        zimFiles
+    }
+    
+    func bulkInsert(handler: @escaping (ZimFile) -> Bool) throws -> Int {
+        var count = 0
+        var zimFile = ZimFile(context: objectContext)
+        while handler(zimFile) == false {
+            zimFiles.append(zimFile)
+            zimFile = ZimFile(context: objectContext)
+            count += 1
+        }
+        return count
+    }
+    
+    func bulkDeleteNotDownloadedZims(notIncludedIn: Set<UUID>) throws -> Int {
+        let oldCount = zimFiles.count
+        zimFiles = zimFiles.filter { zimFile in
+            notIncludedIn.contains(zimFile.fileID) || zimFile.fileURLBookmark != nil
+        }
+        let newCount = zimFiles.count
+        return oldCount - newCount
+    }
+    
+}
+
+final class TestDatabase: Databasing {
+    
+    var context: DBObjectContext = TestContext()
+    
+    func backgroundTask(_ block: @escaping (any DBObjectContext) -> Void) {
+        block(context)
+    }
+}

ViewModel/LibraryViewModel.swift

@@ -43,48 +43,67 @@ enum LibraryState {
     }
 }
 
-@MainActor
-final class MultiSelectedZimFilesViewModel: ObservableObject {
-    @Published private(set) var selectedZimFiles = Set<ZimFile>()
-    
-    func toggleMultiSelect(of zimFile: ZimFile) {
-        if selectedZimFiles.contains(zimFile) {
-            selectedZimFiles.remove(zimFile)
-        } else {
-            selectedZimFiles.insert(zimFile)
-        }
+// MARK: database protocols
+
+protocol Databasing {
+    var context: DBObjectContext { get }
+    func backgroundTask(_ block: @escaping (DBObjectContext) -> Void)
+}
+
+extension Database: Databasing {
+    var context: any DBObjectContext {
+        viewContext
     }
     
-    func singleSelect(zimFile: ZimFile) {
-        selectedZimFiles = Set([zimFile])
-    }
-    
-    func reset() {
-        selectedZimFiles.removeAll()
-    }
-    
-    func isSelected(_ zimFile: ZimFile) -> Bool {
-        selectedZimFiles.contains(zimFile)
-    }
-    
-    func intersection(with zimFiles: Set<ZimFile>) {
-        selectedZimFiles = selectedZimFiles.intersection(zimFiles)
+    func backgroundTask(_ block: @escaping (any DBObjectContext) -> Void) {
+        performBackgroundTask(block)
     }
 }
 
-@MainActor
-final class SelectedZimFileViewModel: ObservableObject {
-    @Published var selectedZimFile: ZimFile?
-    
-    func reset() {
-        selectedZimFile = nil
+protocol DBObjectContext {
+    func fetchZimFiles() throws -> [ZimFile]
+    func bulkInsert(handler: @escaping (ZimFile) -> Bool) throws -> Int
+    func bulkDeleteNotDownloadedZims(notIncludedIn: Set<UUID>) throws -> Int
+}
+
+extension NSManagedObjectContext: DBObjectContext {
+    func bulkInsert(handler: @escaping (ZimFile) -> Bool) throws -> Int {
+        let insertRequest = NSBatchInsertRequest(
+            entity: ZimFile.entity(),
+            managedObjectHandler: { zimFile in
+                guard let zimFile = zimFile as? ZimFile else { return true }
+                return handler(zimFile)
+            }
+        )
+        insertRequest.resultType = .count
+        if let result = try execute(insertRequest) as? NSBatchInsertResult {
+            return result.result as? Int ?? 0
+        } else {
+            return 0
+        }
     }
     
-    func isSelected(_ zimFile: ZimFile) -> Bool {
-        selectedZimFile == zimFile
+    func bulkDeleteNotDownloadedZims(notIncludedIn: Set<UUID>) throws -> Int {
+        let fetchRequest: NSFetchRequest<NSFetchRequestResult> = ZimFile.fetchRequest()
+        fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [
+            ZimFile.Predicate.notDownloaded,
+            NSPredicate(format: "NOT fileID IN %@", notIncludedIn)
+        ])
+        let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
+        deleteRequest.resultType = .resultTypeCount
+        if let result = try execute(deleteRequest) as? NSBatchDeleteResult {
+            return result.result as? Int ?? 0
+        }
+        return 0
+    }
+    
+    func fetchZimFiles() throws -> [ZimFile] {
+        try fetch(ZimFile.fetchRequest())
     }
 }
 
+// MARK: LibraryViewModel
+
 final class LibraryViewModel: ObservableObject {
     @MainActor @Published private(set) var error: Error?
     /// Note: due to multiple instances of LibraryViewModel,
@@ -94,6 +113,7 @@ final class LibraryViewModel: ObservableObject {
     private var cancellables = Set<AnyCancellable>()
     private let defaults: Defaulting
     private let categories: CategoriesProtocol
+    private let database: Databasing
 
     private let urlSession: URLSession
     private var insertionCount = 0
@@ -106,12 +126,14 @@ final class LibraryViewModel: ObservableObject {
         urlSession: URLSession = URLSession.shared,
         processFactory: @MainActor () -> LibraryProcess = { .shared },
         defaults: Defaulting = UDefaults(),
-        categories: CategoriesProtocol = CategoriesToLanguages(withDefaults: UDefaults())
+        categories: CategoriesProtocol = CategoriesToLanguages(withDefaults: UDefaults()),
+        database: Databasing = Database.shared
     ) {
         self.urlSession = urlSession
         self.process = processFactory()
         self.defaults = defaults
         self.categories = categories
+        self.database = database
         state = process.state
         process.$state.sink { [weak self] newState in
             self?.state = newState
@@ -140,8 +162,8 @@ final class LibraryViewModel: ObservableObject {
                 // but we still need to refresh the memory only stored
                 // zimfile categories to languages dictionary
                 if categories.allCategories().count < 2 {
-                    let context =  Database.shared.viewContext
-                    if let zimFiles: [ZimFile] = try? context.fetch(ZimFile.fetchRequest()) {
+                    let context = database.context
+                    if let zimFiles: [ZimFile] = try? context.fetchZimFiles() {
                         saveCategoryAvailableInLanguages(fromDBZimFiles: zimFiles)
                         // populate library language code if there isn't one set already
                         await setDefaultContentFilterLanguage()
@@ -298,44 +320,33 @@ final class LibraryViewModel: ObservableObject {
 
     private func process(parser: Parser) async throws {
         try await withCheckedThrowingContinuation { [weak self] continuation in
-            Database.shared.performBackgroundTask { [weak self] context in
+            guard let self else {
+                continuation.resume()
+                return
+            }
+            self.database.backgroundTask { [weak self] context in
                 guard let self else {
                     continuation.resume()
                     return
                 }
                 do {
                     // insert new zim files
-                    let existing = try context.fetch(ZimFile.fetchRequest()).map { $0.fileID }
+                    let existing = try context.fetchZimFiles().map { $0.fileID }
                     var zimFileIDs = parser.zimFileIDs.subtracting(existing)
-                    let insertRequest = NSBatchInsertRequest(
-                        entity: ZimFile.entity(),
-                        managedObjectHandler: { zimFile in
-                            guard let zimFile = zimFile as? ZimFile else { return true }
-                            while !zimFileIDs.isEmpty {
-                                guard let id = zimFileIDs.popFirst(),
-                                      let metadata = parser.getMetaData(id: id) else { continue }
-                                LibraryOperations.configureZimFile(zimFile, metadata: metadata)
-                                return false
-                            }
-                            return true
+                    
+                    self.insertionCount = try context.bulkInsert { zimFile in
+                        while !zimFileIDs.isEmpty {
+                            guard let id = zimFileIDs.popFirst(),
+                                  let metadata = parser.getMetaData(id: id) else { continue }
+                            LibraryOperations.configureZimFile(zimFile, metadata: metadata)
+                            return false
                         }
-                    )
-                    insertRequest.resultType = .count
-                    if let result = try context.execute(insertRequest) as? NSBatchInsertResult {
-                        self.insertionCount = result.result as? Int ?? 0
+                        return true
                     }
-
+                    
                     // delete old zim entries not included in the feed
-                    let fetchRequest: NSFetchRequest<NSFetchRequestResult> = ZimFile.fetchRequest()
-                    fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [
-                        ZimFile.Predicate.notDownloaded,
-                        NSPredicate(format: "NOT fileID IN %@", parser.zimFileIDs)
-                    ])
-                    let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
-                    deleteRequest.resultType = .resultTypeCount
-                    if let result = try context.execute(deleteRequest) as? NSBatchDeleteResult {
-                        self.deletionCount = result.result as? Int ?? 0
-                    }
+                    self.deletionCount = try context.bulkDeleteNotDownloadedZims(notIncludedIn: parser.zimFileIDs)
+                    
                     continuation.resume()
                 } catch {
                     os_log("Error saving OPDS Data: %s", log: Log.OPDS, type: .error, error.localizedDescription)

ViewModel/ZimSelectionViewModels.swift

@@ -0,0 +1,58 @@
+// This file is part of Kiwix for iOS & macOS.
+//
+// Kiwix is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// any later version.
+//
+// Kiwix is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Kiwix; If not, see https://www.gnu.org/licenses/.
+
+import SwiftUI
+
+@MainActor
+final class MultiSelectedZimFilesViewModel: ObservableObject {
+    @Published private(set) var selectedZimFiles = Set<ZimFile>()
+    
+    func toggleMultiSelect(of zimFile: ZimFile) {
+        if selectedZimFiles.contains(zimFile) {
+            selectedZimFiles.remove(zimFile)
+        } else {
+            selectedZimFiles.insert(zimFile)
+        }
+    }
+    
+    func singleSelect(zimFile: ZimFile) {
+        selectedZimFiles = Set([zimFile])
+    }
+    
+    func reset() {
+        selectedZimFiles.removeAll()
+    }
+    
+    func isSelected(_ zimFile: ZimFile) -> Bool {
+        selectedZimFiles.contains(zimFile)
+    }
+    
+    func intersection(with zimFiles: Set<ZimFile>) {
+        selectedZimFiles = selectedZimFiles.intersection(zimFiles)
+    }
+}
+
+@MainActor
+final class SelectedZimFileViewModel: ObservableObject {
+    @Published var selectedZimFile: ZimFile?
+    
+    func reset() {
+        selectedZimFile = nil
+    }
+    
+    func isSelected(_ zimFile: ZimFile) -> Bool {
+        selectedZimFile == zimFile
+    }
+}