Add missing test coverage to the event notification centre

Author: nuno-vieira

Sources/StreamChat/Workers/EventNotificationCenter.swift

@@ -66,10 +66,6 @@ class EventNotificationCenter: NotificationCenter, @unchecked Sendable {
 
         database.write({ session in
             events.forEach { event in
-                guard let eventDTO = event as? EventDTO else {
-                    middlewareEvents.append(event)
-                    return
-                }
                 if let manualEvent = self.manualEventHandler.handle(event) {
                     manualHandlingEvents.append(manualEvent)
                 } else {

StreamChat.xcodeproj/project.pbxproj

@@ -1618,6 +1618,7 @@
 		AD7C76752E3D0486009250FB /* DemoLivestreamReactionsListView.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7C76742E3D047E009250FB /* DemoLivestreamReactionsListView.swift */; };
 		AD7C76812E4275B3009250FB /* LivestreamChannelController_Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7C76802E4275B3009250FB /* LivestreamChannelController_Tests.swift */; };
 		AD7C76832E42C0B5009250FB /* LivestreamChannelController+Combine_Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7C76822E42C0B5009250FB /* LivestreamChannelController+Combine_Tests.swift */; };
+		AD7C76852E42CDF6009250FB /* ManualEventHandler_Mock.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7C76842E42CDF6009250FB /* ManualEventHandler_Mock.swift */; };
 		AD7CF1712694ABCE00F3101D /* ComposerVC_Documentation_Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7CF16F2694ABC500F3101D /* ComposerVC_Documentation_Tests.swift */; };
 		AD7DFC3625D2FA8100DD9DA3 /* CurrentUserUpdater.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7DFC3525D2FA8100DD9DA3 /* CurrentUserUpdater.swift */; };
 		AD7EFDA72C7796D400625FC5 /* PollCommentListVC.swift in Sources */ = {isa = PBXBuildFile; fileRef = AD7EFDA52C77749300625FC5 /* PollCommentListVC.swift */; };
@@ -4419,6 +4420,7 @@
 		AD7C76742E3D047E009250FB /* DemoLivestreamReactionsListView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DemoLivestreamReactionsListView.swift; sourceTree = "<group>"; };
 		AD7C76802E4275B3009250FB /* LivestreamChannelController_Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LivestreamChannelController_Tests.swift; sourceTree = "<group>"; };
 		AD7C76822E42C0B5009250FB /* LivestreamChannelController+Combine_Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "LivestreamChannelController+Combine_Tests.swift"; sourceTree = "<group>"; };
+		AD7C76842E42CDF6009250FB /* ManualEventHandler_Mock.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ManualEventHandler_Mock.swift; sourceTree = "<group>"; };
 		AD7CF16F2694ABC500F3101D /* ComposerVC_Documentation_Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ComposerVC_Documentation_Tests.swift; sourceTree = "<group>"; };
 		AD7D633225AF577E0051219B /* UserUpdateResponse+MissingUser.json */ = {isa = PBXFileReference; lastKnownFileType = text.json; path = "UserUpdateResponse+MissingUser.json"; sourceTree = "<group>"; };
 		AD7DFBEB25D2AE7400DD9DA3 /* TestDataModel2.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = TestDataModel2.xcdatamodel; sourceTree = "<group>"; };
@@ -7320,6 +7322,7 @@
 		A364D09727D0C5940029857A /* Workers */ = {
 			isa = PBXGroup;
 			children = (
+				AD7C76842E42CDF6009250FB /* ManualEventHandler_Mock.swift */,
 				882C5762252C7F6500E60C44 /* ChannelMemberListUpdater_Mock.swift */,
 				88F6DF96252C88BB009A8AF0 /* ChannelMemberUpdater_Mock.swift */,
 				F62D143D24DD70190081D241 /* ChannelUpdater_Mock.swift */,
@@ -11432,6 +11435,7 @@
 				A3C3BC3F27E87F5C00224761 /* ChannelListUpdater_Spy.swift in Sources */,
 				A3C3BC6427E8AA0A00224761 /* ChannelId+Unique.swift in Sources */,
 				82F714A12B077F3300442A74 /* XCTestCase+iOS13.swift in Sources */,
+				AD7C76852E42CDF6009250FB /* ManualEventHandler_Mock.swift in Sources */,
 				A3C3BC7127E8AA4300224761 /* TestFetchedResultsController.swift in Sources */,
 				82E655392B06775D00D64906 /* MockFunc.swift in Sources */,
 				A344078927D753530044F150 /* UserPayload.swift in Sources */,

TestTools/StreamChatTestTools/Mocks/StreamChat/Workers/ManualEventHandler_Mock.swift

@@ -0,0 +1,45 @@
+//
+// Copyright © 2025 Stream.io Inc. All rights reserved.
+//
+
+@testable import StreamChat
+@testable import StreamChatTestTools
+import XCTest
+
+final class ManualEventHandler_Mock: ManualEventHandler {
+    init() {
+        super.init(
+            database: DatabaseContainer_Spy()
+        )
+    }
+
+    static func mock() -> Self {
+        Self()
+    }
+
+    var registerCallCount = 0
+    var registerCalledWith: [ChannelId] = []
+
+    override func register(channelId: ChannelId) {
+        registerCallCount += 1
+        registerCalledWith.append(channelId)
+    }
+
+    var unregisterCallCount = 0
+    var unregisterCalledWith: [ChannelId] = []
+
+    override func unregister(channelId: ChannelId) {
+        unregisterCallCount += 1
+        unregisterCalledWith.append(channelId)
+    }
+
+    var handleCallCount = 0
+    var handleCalledWith: [Event] = []
+    var handleReturnValue: Event?
+
+    override func handle(_ event: Event) -> Event? {
+        handleCallCount += 1
+        handleCalledWith.append(event)
+        return handleReturnValue
+    }
+}

Tests/StreamChatTests/Workers/EventNotificationCenter_Tests.swift

@@ -275,4 +275,79 @@ final class EventNotificationCenter_Tests: XCTestCase {
             center.process(events)
         }
     }
+
+    // MARK: - Manual Event Handling Tests
+
+    func test_registerManualEventHandling_callsManualEventHandler() {
+        let mockHandler = ManualEventHandler_Mock()
+        let center = EventNotificationCenter(database: database, manualEventHandler: mockHandler)
+        let cid: ChannelId = .unique
+
+        center.registerManualEventHandling(for: cid)
+
+        XCTAssertEqual(mockHandler.registerCallCount, 1)
+        XCTAssertEqual(mockHandler.registerCalledWith, [cid])
+    }
+
+    func test_unregisterManualEventHandling_callsManualEventHandler() {
+        let mockHandler = ManualEventHandler_Mock()
+        let center = EventNotificationCenter(database: database, manualEventHandler: mockHandler)
+        let cid: ChannelId = .unique
+
+        center.unregisterManualEventHandling(for: cid)
+
+        XCTAssertEqual(mockHandler.unregisterCallCount, 1)
+        XCTAssertEqual(mockHandler.unregisterCalledWith, [cid])
+    }
+
+    func test_process_whenManualEventHandlerReturnsEvent_eventIsAddedToEventsToPost() {
+        let mockHandler = ManualEventHandler_Mock()
+        let center = EventNotificationCenter(database: database, manualEventHandler: mockHandler)
+        
+        // Create event logger to check published events
+        let eventLogger = EventLogger(center)
+        
+        // Create test event and mock return value
+        let originalEvent = TestEvent()
+        let manualEvent = TestEvent()
+        mockHandler.handleReturnValue = manualEvent
+        
+        // Process event
+        center.process(originalEvent)
+        
+        // Verify manual handler was called with original event
+        AssertAsync {
+            Assert.willBeEqual(mockHandler.handleCallCount, 1)
+            Assert.willBeEqual(mockHandler.handleCalledWith as? [TestEvent], [originalEvent])
+            // Verify manual event was posted
+            Assert.willBeEqual(eventLogger.events as? [TestEvent], [manualEvent])
+        }
+    }
+
+    func test_process_whenManualEventHandlerReturnsNil_eventIsProcessedByMiddlewares() {
+        let mockHandler = ManualEventHandler_Mock()
+        let center = EventNotificationCenter(database: database, manualEventHandler: mockHandler)
+        
+        // Create event logger to check published events
+        let eventLogger = EventLogger(center)
+        
+        // Create test event
+        let originalEvent = TestEvent()
+        mockHandler.handleReturnValue = nil // Manual handler doesn't handle this event
+        
+        // Add a middleware that will process the event
+        let middleware = EventMiddleware_Mock { event, _ in event }
+        center.add(middleware: middleware)
+        
+        // Process event
+        center.process(originalEvent)
+        
+        // Verify manual handler was called with original event
+        AssertAsync {
+            Assert.willBeEqual(mockHandler.handleCallCount, 1)
+            Assert.willBeEqual(mockHandler.handleCalledWith as? [TestEvent], [originalEvent])
+            // Verify original event was posted (processed by middleware)
+            Assert.willBeEqual(eventLogger.events as? [TestEvent], [originalEvent])
+        }
+    }
 }