add NSE sources to EX project to easily implement mocking and allow the code to be unit tested

ElementX/Sources/Mocks/NotificationItemProxyMock.swift

@@ -0,0 +1,55 @@
+//
+// Copyright 2025 Element Creations Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+// Please see LICENSE files in the repository root for full details.
+//
+
+import Foundation
+import MatrixRustSDK
+
+struct NotificationItemProxyMockConfiguration {
+    var event: NotificationEvent? = {
+        // This is likely the most common notification kind
+        // So it's also the best to use as a default test
+        let messageType = MessageType.text(content: TextMessageContent(body: "Hello world!", formatted: nil))
+        let messageLikeContent = MessageLikeEventContent.roomMessage(messageType: messageType, inReplyToEventId: nil)
+        let event = TimelineEventSDKMock()
+        event.eventIdUnderlyingReturnValue = UUID().uuidString
+        event.eventTypeReturnValue = TimelineEventType.messageLike(content: messageLikeContent)
+        return .timeline(event: event)
+    }()
+    
+    var senderID: String = UUID().uuidString
+    var roomID: String = UUID().uuidString
+    var receiverID: String = UUID().uuidString
+    var senderDisplayName: String?
+    var senderAvatarMediaSource: MediaSourceProxy?
+    var roomAvatarMediaSource: MediaSourceProxy?
+    var roomDisplayName: String
+    var roomJoinedMembers = 2
+    var isRoomDirect = false
+    var isRoomPrivate = false
+    var isNoisy = false
+    var hasMention = false
+    var threadRootEventID: String?
+}
+
+extension NotificationItemProxyMock {
+    convenience init(_ configuration: NotificationItemProxyMockConfiguration) {
+        self.init()
+        event = configuration.event
+        underlyingSenderID = configuration.senderID
+        underlyingRoomID = configuration.roomID
+        underlyingReceiverID = configuration.receiverID
+        senderDisplayName = configuration.senderDisplayName
+        roomAvatarMediaSource = configuration.roomAvatarMediaSource
+        underlyingRoomDisplayName = configuration.roomDisplayName
+        underlyingRoomJoinedMembers = configuration.roomJoinedMembers
+        underlyingIsRoomDirect = configuration.isRoomDirect
+        underlyingIsRoomPrivate = configuration.isRoomPrivate
+        underlyingIsNoisy = configuration.isNoisy
+        underlyingHasMention = configuration.hasMention
+        threadRootEventID = configuration.threadRootEventID
+    }
+}