diff --git a/ElementX/Sources/Mocks/TimelineControllerFactoryMock.swift b/ElementX/Sources/Mocks/TimelineControllerFactoryMock.swift
index a39705179..083b1dc5c 100644
--- a/ElementX/Sources/Mocks/TimelineControllerFactoryMock.swift
+++ b/ElementX/Sources/Mocks/TimelineControllerFactoryMock.swift
@@ -17,18 +17,19 @@ extension TimelineControllerFactoryMock {
     convenience init(_ configuration: Configuration) {
         self.init()
         
-        buildTimelineControllerRoomProxyInitialFocussedEventIDTimelineItemFactoryMediaProviderReturnValue = configuration.timelineController ?? {
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.largeChunk
-            return timelineController
-        }()
+        buildTimelineControllerRoomProxyInitialFocussedEventIDTimelineItemFactoryMediaProviderClosure = { _, _, _, _ in
+            if let timelineController = configuration.threadTimelineController {
+                return timelineController
+            } else {
+                return MockTimelineController(timelineItems: RoomTimelineItemFixtures.largeChunk)
+            }
+        }
         
         buildThreadTimelineControllerThreadRootEventIDInitialFocussedEventIDRoomProxyTimelineItemFactoryMediaProviderClosure = { threadRootEventID, _, _, _, _ in
-            if let threadTimelineController = configuration.threadTimelineController {
-                return .success(threadTimelineController)
+            if let timelineController = configuration.threadTimelineController {
+                return .success(timelineController)
             } else {
-                let timelineController = MockTimelineController(timelineKind: .thread(rootEventID: threadRootEventID))
-                timelineController.timelineItems = RoomTimelineItemFixtures.largeChunk
+                let timelineController = MockTimelineController(timelineKind: .thread(rootEventID: threadRootEventID), timelineItems: RoomTimelineItemFixtures.largeChunk)
                 return .success(timelineController)
             }
         }
diff --git a/ElementX/Sources/Screens/FilePreviewScreen/TimelineMediaPreviewModifier.swift b/ElementX/Sources/Screens/FilePreviewScreen/TimelineMediaPreviewModifier.swift
index ad547b0a9..2024f59b0 100644
--- a/ElementX/Sources/Screens/FilePreviewScreen/TimelineMediaPreviewModifier.swift
+++ b/ElementX/Sources/Screens/FilePreviewScreen/TimelineMediaPreviewModifier.swift
@@ -163,8 +163,7 @@ struct TimelineMediaPreviewModifier_Previews: PreviewProvider {
                                                        thumbnailSource: nil,
                                                        contentType: .pdf))
         
-        let timelineController = MockTimelineController(timelineKind: .media(.mediaFilesScreen))
-        timelineController.timelineItems = [item]
+        let timelineController = MockTimelineController(timelineKind: .media(.mediaFilesScreen), timelineItems: [item])
         
         let mediaProvider = MediaProviderMock(.init())
         
diff --git a/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewDetailsView.swift b/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewDetailsView.swift
index 8505da802..e61ca3de8 100644
--- a/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewDetailsView.swift
+++ b/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewDetailsView.swift
@@ -224,8 +224,7 @@ struct TimelineMediaPreviewDetailsView_Previews: PreviewProvider, TestablePrevie
                                                         contentType: contentType))
         
         let timelineKind = TimelineKind.media(isPresentedOnRoomScreen ? .roomScreenLive : .mediaFilesScreen)
-        let timelineController = MockTimelineController(timelineKind: timelineKind)
-        timelineController.timelineItems = [item]
+        let timelineController = MockTimelineController(timelineKind: timelineKind, timelineItems: [item])
         
         let viewModel = TimelineMediaPreviewViewModel(initialItem: item,
                                                       timelineViewModel: TimelineViewModel.mock(timelineKind: timelineKind,
diff --git a/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewRedactConfirmationView.swift b/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewRedactConfirmationView.swift
index b52a9213e..14819922a 100644
--- a/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewRedactConfirmationView.swift
+++ b/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewRedactConfirmationView.swift
@@ -142,8 +142,7 @@ struct TimelineMediaPreviewRedactConfirmationView_Previews: PreviewProvider, Tes
                                                         thumbnailInfo: .mockThumbnail,
                                                         contentType: contentType))
         
-        let timelineController = MockTimelineController(timelineKind: .media(.mediaFilesScreen))
-        timelineController.timelineItems = [item]
+        let timelineController = MockTimelineController(timelineKind: .media(.mediaFilesScreen), timelineItems: [item])
         return TimelineMediaPreviewViewModel(initialItem: item,
                                              timelineViewModel: TimelineViewModel.mock(timelineKind: timelineController.timelineKind,
                                                                                        timelineController: timelineController),
diff --git a/ElementX/Sources/Screens/PinnedEventsTimelineScreen/View/PinnedEventsTimelineScreen.swift b/ElementX/Sources/Screens/PinnedEventsTimelineScreen/View/PinnedEventsTimelineScreen.swift
index 40b244cfd..bc81378f1 100644
--- a/ElementX/Sources/Screens/PinnedEventsTimelineScreen/View/PinnedEventsTimelineScreen.swift
+++ b/ElementX/Sources/Screens/PinnedEventsTimelineScreen/View/PinnedEventsTimelineScreen.swift
@@ -72,8 +72,7 @@ struct PinnedEventsTimelineScreen_Previews: PreviewProvider, TestablePreview {
                                                                analyticsService: AnalyticsServiceMock(.init()))
     
     static let emptyTimelineViewModel: TimelineViewModel = {
-        let timelineController = MockTimelineController(timelineKind: .pinned)
-        timelineController.timelineItems = []
+        let timelineController = MockTimelineController(timelineKind: .pinned, timelineItems: [])
         
         let appSettings = AppSettings.volatile()
         
diff --git a/ElementX/Sources/Screens/RoomPollsHistoryScreen/View/RoomPollsHistoryScreen.swift b/ElementX/Sources/Screens/RoomPollsHistoryScreen/View/RoomPollsHistoryScreen.swift
index 9cbc6a9e1..ee7f18523 100644
--- a/ElementX/Sources/Screens/RoomPollsHistoryScreen/View/RoomPollsHistoryScreen.swift
+++ b/ElementX/Sources/Screens/RoomPollsHistoryScreen/View/RoomPollsHistoryScreen.swift
@@ -115,8 +115,7 @@ private extension DateFormatter {
 
 struct RoomPollsHistoryScreen_Previews: PreviewProvider, TestablePreview {
     static let viewModelEmpty: RoomPollsHistoryScreenViewModel = {
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = []
+        let timelineController = MockTimelineController(timelineItems: [])
         let roomProxyMockConfiguration = JoinedRoomProxyMockConfiguration(name: "Polls")
         return RoomPollsHistoryScreenViewModel(pollInteractionHandler: PollInteractionHandlerMock(),
                                                timelineController: timelineController,
@@ -124,20 +123,20 @@ struct RoomPollsHistoryScreen_Previews: PreviewProvider, TestablePreview {
     }()
     
     static let viewModel: RoomPollsHistoryScreenViewModel = {
-        let timelineController = MockTimelineController()
-        
         let polls = [PollRoomTimelineItem.mock(poll: .disclosed(createdByAccountOwner: false)),
                      PollRoomTimelineItem.mock(poll: .disclosed(createdByAccountOwner: true)),
                      PollRoomTimelineItem.mock(poll: .emptyDisclosed, isEditable: true)]
         
-        timelineController.timelineItems = polls
-        
+        var timelineItemsTimestamps = [TimelineItemIdentifier: Date]()
         for i in 0..<polls.count {
             let item = polls[i]
             let date: Date! = DateComponents(calendar: .current, timeZone: .gmt, year: 2023, month: 12, day: 1 + i, hour: 12).date
-            timelineController.timelineItemsTimestamp[item.id] = date
+            timelineItemsTimestamps[item.id] = date
         }
         
+        let timelineController = MockTimelineController(timelineItems: polls,
+                                                        timelineItemsTimestamps: timelineItemsTimestamps)
+        
         let roomProxyMockConfiguration = JoinedRoomProxyMockConfiguration(name: "Polls", timelineStartReached: true)
         return RoomPollsHistoryScreenViewModel(pollInteractionHandler: PollInteractionHandlerMock(),
                                                timelineController: timelineController,
diff --git a/ElementX/Sources/Services/Timeline/TimelineController/MockTimelineController.swift b/ElementX/Sources/Services/Timeline/TimelineController/MockTimelineController.swift
index bf35182a8..e63a58b8b 100644
--- a/ElementX/Sources/Services/Timeline/TimelineController/MockTimelineController.swift
+++ b/ElementX/Sources/Services/Timeline/TimelineController/MockTimelineController.swift
@@ -16,34 +16,34 @@ class MockTimelineController: TimelineControllerProtocol {
     private let lastInsertedMessageID: TimelineItemIdentifier = .event(uniqueID: .init("last_message"),
                                                                        eventOrTransactionID: .eventID("last_message"))
     
-    /// An array of timeline item arrays that will be inserted in order for each back pagination request.
-    var backPaginationResponses: [[RoomTimelineItemProtocol]] = []
-    
-    var roomProxy: JoinedRoomProxyProtocol?
-    var timelineProxy: TimelineProxyProtocol?
+    private var roomProxy: JoinedRoomProxyProtocol?
+    private var timelineProxy: TimelineProxyProtocol?
     
     var roomID: String {
         roomProxy?.id ?? "MockRoomIdentifier"
     }
     
-    var timelineKind: TimelineKind
+    private(set) var timelineKind: TimelineKind
     
     let callbacks = PassthroughSubject<TimelineControllerCallback, Never>()
     
+    private(set) var timelineItems: [RoomTimelineItemProtocol] = RoomTimelineItemFixtures.default {
+        didSet {
+            callbacks.send(.updatedTimelineItems(timelineItems: timelineItems, isSwitchingTimelines: false))
+        }
+    }
+    
+    private let timelineItemsTimestamps: [TimelineItemIdentifier: Date]
+    
+    /// An array of timeline item arrays that will be inserted in order for each back pagination request.
+    var backPaginationResponses: [[RoomTimelineItemProtocol]] = []
+    
     var paginationState: TimelinePaginationState = .initial {
         didSet {
             callbacks.send(.paginationState(paginationState))
         }
     }
     
-    var timelineItems: [RoomTimelineItemProtocol] = RoomTimelineItemFixtures.default {
-        didSet {
-            callbacks.send(.updatedTimelineItems(timelineItems: timelineItems, isSwitchingTimelines: false))
-        }
-    }
-    
-    var timelineItemsTimestamp: [TimelineItemIdentifier: Date] = [:]
-    
     static var mediaGallery: MockTimelineController {
         MockTimelineController(timelineKind: .media(.mediaFilesScreen), timelineItems: (0..<5).reduce([]) { partialResult, _ in
             partialResult + [RoomTimelineItemFixtures.separator] + RoomTimelineItemFixtures.mediaChunk
@@ -56,12 +56,16 @@ class MockTimelineController: TimelineControllerProtocol {
         return mock
     }
     
-    init(timelineKind: TimelineKind = .live,
+    init(roomProxy: JoinedRoomProxyProtocol? = nil,
+         timelineKind: TimelineKind = .live,
          timelineItems: [RoomTimelineItemProtocol] = RoomTimelineItemFixtures.default,
-         timelineProxy: TimelineProxyProtocol? = nil) {
+         timelineProxy: TimelineProxyProtocol? = nil,
+         timelineItemsTimestamps: [TimelineItemIdentifier: Date] = [TimelineItemIdentifier: Date]()) {
+        self.roomProxy = roomProxy
         self.timelineKind = timelineKind
         self.timelineItems = timelineItems
         self.timelineProxy = timelineProxy
+        self.timelineItemsTimestamps = timelineItemsTimestamps
         
         callbacks.send(.paginationState(paginationState))
         callbacks.send(.isLive(true))
@@ -169,7 +173,7 @@ class MockTimelineController: TimelineControllerProtocol {
     }
     
     func eventTimestamp(for itemID: TimelineItemIdentifier) -> Date? {
-        timelineItemsTimestamp[itemID] ?? .now
+        timelineItemsTimestamps[itemID] ?? .now
     }
     
     // MARK: - Sending
diff --git a/ElementX/Sources/UITests/UITestsAppCoordinator.swift b/ElementX/Sources/UITests/UITestsAppCoordinator.swift
index 71ef1aa5c..6c371430a 100644
--- a/ElementX/Sources/UITests/UITestsAppCoordinator.swift
+++ b/ElementX/Sources/UITests/UITestsAppCoordinator.swift
@@ -308,8 +308,7 @@ class MockScreen: Identifiable {
             return navigationStackCoordinator
         case .roomSmallTimeline:
             let navigationStackCoordinator = NavigationStackCoordinator()
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.smallChunk
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.smallChunk)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "New room", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
@@ -330,8 +329,7 @@ class MockScreen: Identifiable {
             return navigationStackCoordinator
         case .roomSmallTimelineWithReactions:
             let navigationStackCoordinator = NavigationStackCoordinator()
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.default
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.default)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "New room", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
@@ -351,8 +349,7 @@ class MockScreen: Identifiable {
             return navigationStackCoordinator
         case .roomSmallTimelineWithReadReceipts:
             let navigationStackCoordinator = NavigationStackCoordinator()
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.smallChunkWithReadReceipts
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.smallChunkWithReadReceipts)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "New room", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
@@ -504,8 +501,7 @@ class MockScreen: Identifiable {
         case .roomLayoutHighlight:
             let navigationStackCoordinator = NavigationStackCoordinator()
             
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.permalinkChunk
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.permalinkChunk)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "Timeline highlight", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
@@ -540,8 +536,7 @@ class MockScreen: Identifiable {
         case .roomWithDisclosedPolls:
             let navigationStackCoordinator = NavigationStackCoordinator()
             
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.disclosedPolls
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.disclosedPolls)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "Polls timeline", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
@@ -563,8 +558,7 @@ class MockScreen: Identifiable {
         case .roomWithUndisclosedPolls:
             let navigationStackCoordinator = NavigationStackCoordinator()
             
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.undisclosedPolls
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.undisclosedPolls)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "Polls timeline", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
@@ -586,8 +580,7 @@ class MockScreen: Identifiable {
         case .roomWithOutgoingPolls:
             let navigationStackCoordinator = NavigationStackCoordinator()
             
-            let timelineController = MockTimelineController()
-            timelineController.timelineItems = RoomTimelineItemFixtures.outgoingPolls
+            let timelineController = MockTimelineController(timelineItems: RoomTimelineItemFixtures.outgoingPolls)
             let parameters = RoomScreenCoordinatorParameters(userSession: UserSessionMock(.init()),
                                                              roomProxy: JoinedRoomProxyMock(.init(name: "Polls timeline", avatarURL: .mockMXCAvatar)),
                                                              timelineController: timelineController,
diff --git a/UnitTests/Sources/PillContextTests.swift b/UnitTests/Sources/PillContextTests.swift
index 4e3a18dc9..04d0bcacf 100644
--- a/UnitTests/Sources/PillContextTests.swift
+++ b/UnitTests/Sources/PillContextTests.swift
@@ -81,8 +81,7 @@ struct PillContextTests {
         let id = "test_room"
         let displayName = "Test"
         let proxyMock = JoinedRoomProxyMock(.init(id: id, name: displayName, avatarURL: avatarURL))
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let mock = TimelineViewModel(roomProxy: proxyMock,
                                      timelineController: mockController,
                                      userSession: UserSessionMock(.init()),
@@ -106,10 +105,9 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let clientMock = ClientProxyMock(.init())
         clientMock.roomSummaryForIdentifierReturnValue = .mock(id: "1", name: "Foundation 🔭🪐🌌")
-        mockController.roomProxy = proxyMock
         let mock = TimelineViewModel(roomProxy: proxyMock,
                                      timelineController: mockController,
                                      userSession: UserSessionMock(.init(clientProxy: clientMock)),
@@ -134,8 +132,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let mock = TimelineViewModel(roomProxy: proxyMock,
                                      timelineController: mockController,
                                      userSession: UserSessionMock(.init()),
@@ -160,8 +157,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let clientMock = ClientProxyMock(.init())
         clientMock.roomSummaryForAliasReturnValue = .mock(id: "2",
                                                           name: "Foundation and Empire",
@@ -190,8 +186,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let mock = TimelineViewModel(roomProxy: proxyMock,
                                      timelineController: mockController,
                                      userSession: UserSessionMock(.init()),
@@ -216,8 +211,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let clientMock = ClientProxyMock(.init())
         clientMock.roomSummaryForIdentifierReturnValue = .mock(id: "1", name: "Foundation 🔭🪐🌌")
         let mock = TimelineViewModel(roomProxy: proxyMock,
@@ -244,8 +238,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let mock = TimelineViewModel(roomProxy: proxyMock,
                                      timelineController: mockController,
                                      userSession: UserSessionMock(.init()),
@@ -270,8 +263,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let clientMock = ClientProxyMock(.init())
         clientMock.roomSummaryForAliasReturnValue = .mock(id: "2",
                                                           name: "Foundation and Empire",
@@ -300,8 +292,7 @@ struct PillContextTests {
         let userIndicatorController = UserIndicatorControllerMock()
         
         let proxyMock = JoinedRoomProxyMock(.init())
-        let mockController = MockTimelineController()
-        mockController.roomProxy = proxyMock
+        let mockController = MockTimelineController(roomProxy: proxyMock)
         let mock = TimelineViewModel(roomProxy: proxyMock,
                                      timelineController: mockController,
                                      userSession: UserSessionMock(.init()),
diff --git a/UnitTests/Sources/TimelineMediaPreviewViewModelTests.swift b/UnitTests/Sources/TimelineMediaPreviewViewModelTests.swift
index faeca611c..12a05ab50 100644
--- a/UnitTests/Sources/TimelineMediaPreviewViewModelTests.swift
+++ b/UnitTests/Sources/TimelineMediaPreviewViewModelTests.swift
@@ -292,8 +292,7 @@ struct TimelineMediaPreviewViewModelTests {
     
     private mutating func setupViewModel(initialItemIndex: Int = 0, photoLibraryAuthorizationDenied: Bool = false) {
         let initialItems = makeItems()
-        timelineController = MockTimelineController(timelineKind: .media(.mediaFilesScreen))
-        timelineController.timelineItems = initialItems
+        timelineController = MockTimelineController(timelineKind: .media(.mediaFilesScreen), timelineItems: initialItems)
         
         mediaProvider = MediaProviderMock(.init())
         photoLibraryManager = PhotoLibraryManagerMock(.init(authorizationDenied: photoLibraryAuthorizationDenied))
diff --git a/UnitTests/Sources/TimelineViewModelTests.swift b/UnitTests/Sources/TimelineViewModelTests.swift
index d7f4e1067..f38c65bc3 100644
--- a/UnitTests/Sources/TimelineViewModelTests.swift
+++ b/UnitTests/Sources/TimelineViewModelTests.swift
@@ -35,8 +35,7 @@ final class TimelineViewModelTests {
         ]
         
         // When showing them in a timeline.
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         // Then the messages should be grouped together.
@@ -64,8 +63,7 @@ final class TimelineViewModelTests {
         ]
         
         // When showing them in a timeline.
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         // Then the messages should be grouped by sender.
@@ -91,8 +89,7 @@ final class TimelineViewModelTests {
         ]
         
         // When showing them in a timeline.
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         // Then the first message should not be grouped but the other two should.
@@ -115,8 +112,7 @@ final class TimelineViewModelTests {
         ]
         
         // When showing them in a timeline.
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         // Then the first and second messages should be grouped and the last one should not.
@@ -139,8 +135,7 @@ final class TimelineViewModelTests {
         ]
         
         // When showing them in a timeline.
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         // Then the messages should be grouped together.
@@ -157,8 +152,7 @@ final class TimelineViewModelTests {
         let items = [TextRoomTimelineItem(eventID: "t1"),
                      TextRoomTimelineItem(eventID: "t2"),
                      TextRoomTimelineItem(eventID: "t3")]
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         
         let viewModel = makeViewModel(timelineController: timelineController)
         #expect(timelineController.focusOnEventCallCount == 0)
@@ -182,8 +176,7 @@ final class TimelineViewModelTests {
         let items = [TextRoomTimelineItem(eventID: "t1"),
                      TextRoomTimelineItem(eventID: "t2"),
                      TextRoomTimelineItem(eventID: "t3")]
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         
         let viewModel = makeViewModel(timelineController: timelineController)
         #expect(timelineController.focusOnEventCallCount == 0)
@@ -207,8 +200,7 @@ final class TimelineViewModelTests {
         let items = [TextRoomTimelineItem(eventID: "t1"),
                      TextRoomTimelineItem(eventID: "t2"),
                      TextRoomTimelineItem(eventID: "t3")]
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         
         let viewModel = makeViewModel(timelineController: timelineController)
         
@@ -294,17 +286,13 @@ final class TimelineViewModelTests {
                                                                                        JoinedRoomProxyMock,
                                                                                        TimelineProxyMock,
                                                                                        MockTimelineController) {
-        let roomProxy = JoinedRoomProxyMock(.init(name: ""))
-        
         let timelineProxy = TimelineProxyMock()
-        
-        roomProxy.timeline = timelineProxy
-        let timelineController = MockTimelineController()
-        
         timelineProxy.sendReadReceiptForTypeReturnValue = .success(())
         
-        timelineController.timelineItems = items
-        timelineController.roomProxy = roomProxy
+        let roomProxy = JoinedRoomProxyMock(.init(name: ""))
+        roomProxy.timeline = timelineProxy
+        
+        let timelineController = MockTimelineController(roomProxy: roomProxy, timelineItems: items)
         
         let appSettings = AppSettings.volatile()
         
@@ -335,8 +323,7 @@ final class TimelineViewModelTests {
         let appSettings = AppSettings.volatile()
         
         // When showing them in a timeline.
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = [message]
+        let timelineController = MockTimelineController(timelineItems: [message])
         let viewModel = TimelineViewModel(roomProxy: JoinedRoomProxyMock(.init(name: "", members: [RoomMemberProxyMock.mockAlice, RoomMemberProxyMock.mockCharlie])),
                                           timelineController: timelineController,
                                           userSession: UserSessionMock(.init()),
@@ -556,8 +543,7 @@ final class TimelineViewModelTests {
     func tapSendInfoEncryptionAuthentictyDisplaysAlert() {
         // Given a room with an event whose authenticity could not be verified
         let items = [TextRoomTimelineItem(eventID: "t1", encryptionAuthenticity: .verificationViolation(color: .red))]
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         #expect(viewModel.state.bindings.alertInfo == nil)
@@ -571,8 +557,7 @@ final class TimelineViewModelTests {
     func tapSendInfoEncryptionForwarderDisplaysAlert() {
         // Given a room with an event whose key was forwarded
         let items = [TextRoomTimelineItem(eventID: "t1", keyForwarder: .test)]
-        let timelineController = MockTimelineController()
-        timelineController.timelineItems = items
+        let timelineController = MockTimelineController(timelineItems: items)
         let viewModel = makeViewModel(timelineController: timelineController)
         
         #expect(viewModel.state.bindings.alertInfo == nil)