Cover changes introduced by Web synchronization with unit tests

With changes added by enabling visitor messages to be delivered via socket and using send message payload API, new logic for message processing has been introduced, to handle messages delivered via web-socket and via REST API. These tests cover situations were message via socket gets delivered before REST API and vice versa, to ensure that no visitor message duplications occur.

MOB-2638

GliaWidgets/Sources/Interactor/Interactor.swift

@@ -71,7 +71,7 @@ class Interactor {
             }
         }
     }
-    private var environment: Environment
+    var environment: Environment
 
     init(
         configuration: Configuration,

GliaWidgets/Sources/ViewModel/Chat/ChatViewModel.swift

@@ -930,3 +930,13 @@ extension ChatViewModel {
         }
     }
 }
+
+#if DEBUG
+extension ChatViewModel {
+    /// Sets text and immediately sends it. Used for testing.
+    func invokeSetTextAndSendMessage(text: String) {
+        self.messageText = text
+        self.sendMessage()
+    }
+}
+#endif

GliaWidgetsTests/Sources/ChatViewModel/ChatViewModelTests.swift

@@ -579,6 +579,128 @@ class ChatViewModelTests: XCTestCase {
         }
         XCTAssertEqual(viewModel.receivedMessageIds, [messageId.uppercased()])
     }
+
+    func test_messageReceivedFromSocketWithSameIdIsDiscarded() {
+        var viewModelEnv = ChatViewModel.Environment.failing()
+        viewModelEnv.createFileUploadListModel = { _ in .mock() }
+        viewModelEnv.fileManager.urlsForDirectoryInDomainMask = { _, _ in [.mock] }
+        viewModelEnv.fileManager.createDirectoryAtUrlWithIntermediateDirectories = { _, _, _ in }
+        viewModelEnv.loadChatMessagesFromHistory = { true }
+        viewModelEnv.fetchSiteConfigurations = { _ in }
+        let expectedMessageId = "expected_message_id"
+        viewModelEnv.fetchChatHistory = { callback in
+            callback(.success([]))
+        }
+        let viewModel: ChatViewModel = .mock(environment: viewModelEnv)
+        viewModel.isViewLoaded = true
+        viewModel.start()
+
+        viewModel.interactorEvent(.receivedMessage(.mock(id: expectedMessageId)))
+        viewModel.interactorEvent(.receivedMessage(.mock(id: expectedMessageId)))
+        XCTAssertEqual(viewModel.messagesSection.items.count, 1)
+        XCTAssertEqual(viewModel.receivedMessageIds, [expectedMessageId.uppercased()])
+    }
+
+    func test_messageReceivedFirstFromRestDiscardsSameOneFromSocket() throws {
+        var viewModelEnv = ChatViewModel.Environment.failing()
+        viewModelEnv.createFileUploadListModel = { _ in .mock() }
+        viewModelEnv.fileManager.urlsForDirectoryInDomainMask = { _, _ in [.mock] }
+        viewModelEnv.fileManager.createDirectoryAtUrlWithIntermediateDirectories = { _, _, _ in }
+        viewModelEnv.loadChatMessagesFromHistory = { true }
+        viewModelEnv.fetchSiteConfigurations = { _ in }
+        let messageIdSuffix = "1D_123"
+        let expectedMessageId = "expected_message_id"
+        viewModelEnv.fetchChatHistory = { callback in
+            callback(.success([]))
+        }
+        viewModelEnv.createSendMessagePayload = {
+            .mock(messageIdSuffix: messageIdSuffix, content: $0, attachment: $1)
+        }
+
+        let interactor = Interactor.failing
+        interactor.environment.gcd.mainQueue.asyncIfNeeded = { $0() }
+        interactor.environment.coreSdk.configureWithInteractor = { _ in }
+        interactor.environment.coreSdk.configureWithConfiguration = { _, callback in callback?() }
+        interactor.environment.coreSdk.sendMessagePreview = { _, _ in }
+        interactor.environment.coreSdk.sendMessageWithMessagePayload = { _, completion in
+            completion(.success(.mock(id: expectedMessageId)))
+        }
+        interactor.environment.coreSdk.queueForEngagement = { _, _, _, _, _, completion in
+            completion(.mock, nil)
+        }
+
+        let viewModel: ChatViewModel = .mock(interactor: interactor, environment: viewModelEnv)
+        viewModel.isViewLoaded = true
+        viewModel.start()
+        interactor.state = .engaged(.mock())
+        viewModel.invokeSetTextAndSendMessage(text: "Mock send message.")
+
+        viewModel.interactorEvent(.receivedMessage(.mock(id: expectedMessageId)))
+
+        let lastMessage = viewModel.messagesSection.items.last?.kind
+        var receivedMessage: ChatMessage?
+        switch try XCTUnwrap(lastMessage) {
+        case let .visitorMessage(message, _):
+            receivedMessage = message
+        default:
+            XCTFail("Expected visitor message. Got \(String(describing: lastMessage)) instead.")
+        }
+
+        XCTAssertEqual(viewModel.messagesSection.items.count, 2)
+        XCTAssertEqual(viewModel.receivedMessageIds, [expectedMessageId.uppercased()])
+        XCTAssertEqual(try XCTUnwrap(receivedMessage).id, expectedMessageId)
+    }
+
+    func test_messageReceivedFirstFromSocketDiscardsSameOneFromRest() throws {
+        var viewModelEnv = ChatViewModel.Environment.failing()
+        viewModelEnv.createFileUploadListModel = { _ in .mock() }
+        viewModelEnv.fileManager.urlsForDirectoryInDomainMask = { _, _ in [.mock] }
+        viewModelEnv.fileManager.createDirectoryAtUrlWithIntermediateDirectories = { _, _, _ in }
+        viewModelEnv.loadChatMessagesFromHistory = { true }
+        viewModelEnv.fetchSiteConfigurations = { _ in }
+        let messageIdSuffix = "1D_123"
+        let expectedMessageId = "expected_message_id"
+        viewModelEnv.fetchChatHistory = { callback in
+            callback(.success([]))
+        }
+        viewModelEnv.createSendMessagePayload = {
+            .mock(messageIdSuffix: messageIdSuffix, content: $0, attachment: $1)
+        }
+
+        let interactor = Interactor.failing
+        interactor.environment.gcd.mainQueue.asyncIfNeeded = { $0() }
+        interactor.environment.coreSdk.configureWithInteractor = { _ in }
+        interactor.environment.coreSdk.configureWithConfiguration = { _, callback in callback?() }
+        interactor.environment.coreSdk.sendMessagePreview = { _, _ in }
+        interactor.environment.coreSdk.sendMessageWithMessagePayload = { [weak viewModel] _, completion in
+            // Deliver message via socket before REST API response.
+            viewModel?.interactorEvent(.receivedMessage(.mock(id: expectedMessageId)))
+            completion(.success(.mock(id: expectedMessageId)))
+        }
+        interactor.environment.coreSdk.queueForEngagement = { _, _, _, _, _, completion in
+            completion(.mock, nil)
+        }
+
+        let viewModel: ChatViewModel = .mock(interactor: interactor, environment: viewModelEnv)
+        viewModel.isViewLoaded = true
+        viewModel.start()
+        interactor.state = .engaged(.mock())
+        viewModel.invokeSetTextAndSendMessage(text: "Mock send message.")
+        viewModel.interactorEvent(.receivedMessage(.mock(id: expectedMessageId)))
+
+        let lastMessage = viewModel.messagesSection.items.last?.kind
+        var receivedMessage: ChatMessage?
+        switch try XCTUnwrap(lastMessage) {
+        case let .visitorMessage(message, _):
+            receivedMessage = message
+        default:
+            XCTFail("Expected visitor message. Got \(String(describing: lastMessage)) instead.")
+        }
+
+        XCTAssertEqual(viewModel.messagesSection.items.count, 2)
+        XCTAssertEqual(viewModel.receivedMessageIds, [expectedMessageId.uppercased()])
+        XCTAssertEqual(try XCTUnwrap(receivedMessage).id, expectedMessageId)
+    }
 }
 
 extension ChatChoiceCardOption {