Add missing unit tests (#3711)

Also fix errors and warnings in the log during unit testing.

[ignore-commit-lint]

Co-authored-by: Claude <[email protected]>

Author: vargaat

Core/Core/Common/CommonModels/Store/PreviewStore.swift

@@ -23,10 +23,7 @@ import CoreData
 
 private var singleSharedPreviewDatabase: NSPersistentContainer  = resetSingleSharedPreviewDatabase()
 private func resetSingleSharedPreviewDatabase() -> NSPersistentContainer {
-    let bundle = Bundle.core
-    let modelURL = bundle.url(forResource: "Database", withExtension: "momd")!
-    let model = NSManagedObjectModel(contentsOf: modelURL)!
-    let container = NSPersistentContainer(name: "Database", managedObjectModel: model)
+    let container = NSPersistentContainer(name: "Database", managedObjectModel: .core)
     let description = NSPersistentStoreDescription()
     description.type = NSInMemoryStoreType
     description.shouldAddStoreAsynchronously = false

Core/Core/Common/Extensions/CoreData/NSPersistentContainerExtensions.swift

@@ -19,6 +19,13 @@
 import Combine
 import CoreData
 
+extension NSManagedObjectModel {
+    static let core: NSManagedObjectModel = {
+        let modelFileURL = Bundle.core.url(forResource: "Database", withExtension: "momd")!
+        return NSManagedObjectModel(contentsOf: modelFileURL)!
+    }()
+}
+
 extension NSPersistentContainer {
 
     // MARK: - Public Static Interface
@@ -28,14 +35,18 @@ extension NSPersistentContainer {
     public static func create(appGroup: String? = Bundle.main.appGroupID(),
                               session: LoginSession? = nil)
     -> NSPersistentContainer {
-        let modelFileURL = Bundle.core.url(forResource: "Database", withExtension: "momd")!
-        let model = NSManagedObjectModel(contentsOf: modelFileURL)!
         registerCoreTransformers()
-        let container = NSPersistentContainer(name: "Database", managedObjectModel: model)
+        let container = NSPersistentContainer(name: "Database", managedObjectModel: .core)
+
+        let dbUrl = {
+            let url = URL.Directories.databaseURL(appGroup: appGroup, session: session)
+            let parentDirectory = url.deletingLastPathComponent()
+            try? FileManager.default.createDirectory(at: parentDirectory, withIntermediateDirectories: true, attributes: nil)
+            return  url
+        }()
 
-        let url = URL.Directories.databaseURL(appGroup: appGroup, session: session)
         container.persistentStoreDescriptions = [
-            NSPersistentStoreDescription(url: url)
+            NSPersistentStoreDescription(url: dbUrl)
         ]
 
         container.loadPersistentStores { _, error in

Core/CoreTests/Common/Extensions/Combine/SubjectExtensionsTests.swift

@@ -0,0 +1,99 @@
+//
+// This file is part of Canvas.
+// Copyright (C) 2025-present  Instructure, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+@testable import Core
+import Combine
+import XCTest
+
+class SubjectExtensionsTests: XCTestCase {
+
+    func test_binding_returnsCurrentValue() {
+        let subject = CurrentValueSubject<Int, Never>(42)
+
+        // WHEN
+        let binding = subject.binding
+
+        // THEN
+        XCTAssertEqual(binding.wrappedValue, 42)
+    }
+
+    func test_binding_updatesSubjectValue() {
+        let subject = CurrentValueSubject<String, Never>("initial")
+        let binding = subject.binding
+
+        // WHEN
+        binding.wrappedValue = "updated"
+
+        // THEN
+        XCTAssertEqual(subject.value, "updated")
+    }
+
+    func test_binding_worksWithComplexType() {
+        struct TestModel {
+            var name: String
+            var count: Int
+        }
+
+        let initialModel = TestModel(name: "test", count: 5)
+        let subject = CurrentValueSubject<TestModel, Never>(initialModel)
+        let binding = subject.binding
+
+        XCTAssertEqual(binding.wrappedValue.name, "test")
+        XCTAssertEqual(binding.wrappedValue.count, 5)
+
+        // WHEN
+        let updatedModel = TestModel(name: "updated", count: 10)
+        binding.wrappedValue = updatedModel
+
+        // THEN
+        XCTAssertEqual(subject.value.name, "updated")
+        XCTAssertEqual(subject.value.count, 10)
+    }
+
+    func test_binding_worksWithBooleanValue() {
+        let subject = CurrentValueSubject<Bool, Never>(false)
+        let binding = subject.binding
+
+        XCTAssertFalse(binding.wrappedValue)
+
+        // WHEN
+        binding.wrappedValue = true
+
+        // THEN
+        XCTAssertTrue(subject.value)
+    }
+
+    func test_binding_worksWithOptionalValue() {
+        let subject = CurrentValueSubject<Int?, Never>(nil)
+        let binding = subject.binding
+
+        XCTAssertNil(binding.wrappedValue)
+
+        // WHEN
+        binding.wrappedValue = 100
+
+        // THEN
+        XCTAssertEqual(subject.value, 100)
+
+        // WHEN
+        binding.wrappedValue = nil
+
+        // THEN
+        XCTAssertNil(subject.value)
+    }
+}