Modern Swift Concurrency (+actors, +tasks, -GCD, -Combine)

Spawn-App-iOS-SwiftUI.xcodeproj/project.pbxproj

@@ -389,6 +389,7 @@
 				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "DEBUG $(inherited)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 6.0;
 				VERSIONING_SYSTEM = "apple-generic";
 			};
 			name = Debug;
@@ -449,6 +450,7 @@
 				SDKROOT = iphoneos;
 				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_COMPILATION_MODE = wholemodule;
+				SWIFT_VERSION = 6.0;
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";
 			};
@@ -485,7 +487,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_PRECOMPILE_BRIDGING_HEADER = NO;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -521,7 +523,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_PRECOMPILE_BRIDGING_HEADER = NO;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
@@ -538,7 +540,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "danielagapov.Spawn-App-iOS-SwiftUITests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = NO;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Spawn-App-iOS-SwiftUI.app/$(BUNDLE_EXECUTABLE_FOLDER_PATH)/Spawn-App-iOS-SwiftUI";
 			};
@@ -556,7 +558,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "danielagapov.Spawn-App-iOS-SwiftUITests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = NO;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Spawn-App-iOS-SwiftUI.app/$(BUNDLE_EXECUTABLE_FOLDER_PATH)/Spawn-App-iOS-SwiftUI";
 			};
@@ -572,7 +574,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "danielagapov.Spawn-App-iOS-SwiftUIUITests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = NO;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TEST_TARGET_NAME = "Spawn-App-iOS-SwiftUI";
 			};
@@ -588,7 +590,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "danielagapov.Spawn-App-iOS-SwiftUIUITests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = NO;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TEST_TARGET_NAME = "Spawn-App-iOS-SwiftUI";
 			};

Spawn-App-iOS-SwiftUI/ContentView.swift

@@ -255,7 +255,6 @@ struct ContentView: View {
 				.zIndex(999)  // Below notifications but above everything else
 			}
 		}
-		.testInAppNotification()  // Triple-tap anywhere to test in-app notifications
 	}
 
 	// MARK: - Deep Link Handling
@@ -271,7 +270,8 @@ struct ContentView: View {
 		selectedTabsEnum = .home
 
 		// Add a small delay to ensure tab switching completes before setting deep link state
-		DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+		Task { @MainActor in
+			try? await Task.sleep(for: .seconds(0.1))
 			// Set up the deep linked activity state
 			deepLinkedActivityId = activityId
 			shouldShowDeepLinkedActivity = true
@@ -309,7 +309,7 @@ struct ContentView: View {
 
 				if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 {
 					// Show success notification
-					DispatchQueue.main.async {
+					Task { @MainActor in
 						InAppNotificationManager.shared.showNotification(
 							title: "You're invited!",
 							message: "You've been added to this activity. Check it out!",
@@ -335,7 +335,8 @@ struct ContentView: View {
 		selectedTabsEnum = .friends
 
 		// Add a small delay to ensure tab switching completes before setting deep link state
-		DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+		Task { @MainActor in
+			try? await Task.sleep(for: .seconds(0.1))
 			// Set up the deep linked profile state
 			deepLinkedProfileId = profileId
 			shouldShowDeepLinkedProfile = true

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/ActivityCreationResponseDTO.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct ActivityCreationResponseDTO: Codable {
+struct ActivityCreationResponseDTO: Codable, Sendable {
 	let activity: FullFeedActivityDTO
 	let friendSuggestion: ActivityTypeFriendSuggestionDTO?
 
@@ -17,7 +17,7 @@ struct ActivityCreationResponseDTO: Codable {
 	}
 }
 
-struct ActivityTypeFriendSuggestionDTO: Codable {
+struct ActivityTypeFriendSuggestionDTO: Codable, Sendable {
 	let activityTypeId: UUID
 	let activityTypeTitle: String
 	let suggestedFriends: [BaseUserDTO]

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/ActivityDTO.swift

@@ -7,9 +7,11 @@
 
 import Foundation
 
-// Unified ActivityDTO that matches the back-end ActivityDTO structure
-// Replaces both ActivityCreationDTO and handles both creation and updates
-class ActivityDTO: Identifiable, Codable, Equatable, ObservableObject {
+/// Unified ActivityDTO that matches the back-end ActivityDTO structure.
+/// Replaces both ActivityCreationDTO and handles both creation and updates.
+/// Uses @unchecked Sendable because it's a class with mutable state that needs to cross
+/// async boundaries. The mutable state is only modified on MainActor in practice.
+class ActivityDTO: Identifiable, Codable, Equatable, ObservableObject, @unchecked Sendable {
 	static func == (lhs: ActivityDTO, rhs: ActivityDTO) -> Bool {
 		return lhs.id == rhs.id
 	}

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/ActivityPartialUpdateDTO.swift

@@ -8,7 +8,7 @@
 import Foundation
 
 /// DTO for partial activity updates using PATCH requests
-struct ActivityPartialUpdateDTO: Codable {
+struct ActivityPartialUpdateDTO: Codable, Sendable {
 	var title: String?
 	var icon: String?
 	var startTime: String?  // ISO8601 formatted string

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/ActivityTypeDTO.swift

@@ -6,7 +6,7 @@
 //
 import Foundation
 
-class ActivityTypeDTO: Identifiable, Codable, Equatable {
+struct ActivityTypeDTO: Identifiable, Codable, Equatable, Sendable {
 	var id: UUID
 	var title: String
 	var associatedFriends: [BaseUserDTO]
@@ -27,15 +27,10 @@ class ActivityTypeDTO: Identifiable, Codable, Equatable {
 		self.ownerUserId = ownerUserId
 		self.isPinned = isPinned
 	}
-
-	// MARK: - Equatable
-	static func == (lhs: ActivityTypeDTO, rhs: ActivityTypeDTO) -> Bool {
-		return lhs.id == rhs.id
-	}
 }
 
 // DTO for batch updating activity types
-struct BatchActivityTypeUpdateDTO: Codable {
+struct BatchActivityTypeUpdateDTO: Codable, Sendable {
 	let updatedActivityTypes: [ActivityTypeDTO]
 	let deletedActivityTypeIds: [UUID]
 
@@ -46,19 +41,23 @@ struct BatchActivityTypeUpdateDTO: Codable {
 }
 
 extension ActivityTypeDTO {
-	static var mockChillActivityType: ActivityTypeDTO = ActivityTypeDTO(
-		id: UUID(), title: "Chill", icon: "🛋️", associatedFriends: [BaseUserDTO.danielLee, BaseUserDTO.danielAgapov],
+	static let mockChillActivityType: ActivityTypeDTO = ActivityTypeDTO(
+		id: UUID(uuidString: "A1B2C3D4-E5F6-7890-ABCD-EF1234567890") ?? UUID(),
+		title: "Chill", icon: "🛋️", associatedFriends: [BaseUserDTO.danielLee, BaseUserDTO.danielAgapov],
 		orderNum: 0, isPinned: false
 	)
-	static var mockFoodActivityType: ActivityTypeDTO = ActivityTypeDTO(
-		id: UUID(), title: "Food", icon: "🍽️",
+	static let mockFoodActivityType: ActivityTypeDTO = ActivityTypeDTO(
+		id: UUID(uuidString: "B2C3D4E5-F678-9012-BCDE-F12345678901") ?? UUID(),
+		title: "Food", icon: "🍽️",
 		associatedFriends: [BaseUserDTO.danielLee, BaseUserDTO.haley, BaseUserDTO.haley], orderNum: 1, isPinned: true)
-	static var mockActiveActivityType: ActivityTypeDTO = ActivityTypeDTO(
-		id: UUID(), title: "Active", icon: "🏃",
+	static let mockActiveActivityType: ActivityTypeDTO = ActivityTypeDTO(
+		id: UUID(uuidString: "C3D4E5F6-7890-1234-CDEF-123456789012") ?? UUID(),
+		title: "Active", icon: "🏃",
 		associatedFriends: [BaseUserDTO.haley, BaseUserDTO.danielLee, BaseUserDTO.haley, BaseUserDTO.danielLee],
 		orderNum: 2, isPinned: false)
-	static var mockStudyActivityType: ActivityTypeDTO = ActivityTypeDTO(
-		id: UUID(), title: "Study", icon: "✏️", associatedFriends: BaseUserDTO.mockUsers, orderNum: 3, isPinned: false)
+	static let mockStudyActivityType: ActivityTypeDTO = ActivityTypeDTO(
+		id: UUID(uuidString: "D4E5F678-9012-3456-DEF1-234567890123") ?? UUID(),
+		title: "Study", icon: "✏️", associatedFriends: BaseUserDTO.mockUsers, orderNum: 3, isPinned: false)
 
 	/// Creates a new ActivityTypeDTO instance with default values for creating a new activity type
 	static func createNew() -> ActivityTypeDTO {

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/FullFeedActivityDTO.swift

@@ -7,7 +7,10 @@
 
 import Foundation
 
-class FullFeedActivityDTO: Identifiable, Codable, Equatable, ObservableObject {
+/// Full activity DTO with all details for display in the feed.
+/// Uses @unchecked Sendable because it's a class with @Published properties that needs to cross
+/// async boundaries. The mutable state is only modified on MainActor in practice.
+class FullFeedActivityDTO: Identifiable, Codable, Equatable, ObservableObject, @unchecked Sendable {
 	static func == (lhs: FullFeedActivityDTO, rhs: FullFeedActivityDTO) -> Bool {
 		return lhs.id == rhs.id
 	}

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/LocationDTO.swift

@@ -7,11 +7,7 @@
 
 import Foundation
 
-class LocationDTO: Identifiable, Codable, Equatable {
-	static func == (lhs: LocationDTO, rhs: LocationDTO) -> Bool {
-		lhs.latitude == rhs.latitude && lhs.longitude == rhs.longitude && lhs.name == rhs.name
-	}
-
+struct LocationDTO: Identifiable, Codable, Equatable, Sendable {
 	var id: UUID
 	var name: String
 	var latitude: Double

Spawn-App-iOS-SwiftUI/Models/DTOs/Activity/ProfileActivityDTO.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-class ProfileActivityDTO: FullFeedActivityDTO {
+class ProfileActivityDTO: FullFeedActivityDTO, @unchecked Sendable {
 	var isPastActivity: Bool
 
 	// Custom initializer to handle the additional property

Spawn-App-iOS-SwiftUI/Models/DTOs/BlockedUserCreationDTO.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-struct BlockedUserCreationDTO: Codable {
+struct BlockedUserCreationDTO: Codable, Sendable {
 	let blockerId: UUID
 	let blockedId: UUID
 	let reason: String

Spawn-App-iOS-SwiftUI/Models/DTOs/BlockedUserDTO.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-struct BlockedUserDTO: Codable {
+struct BlockedUserDTO: Codable, Sendable {
 	let id: UUID
 	let blockerId: UUID
 	let blockedId: UUID

Spawn-App-iOS-SwiftUI/Models/DTOs/CacheValidationResponse.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct CacheValidationResponse: Codable {
+struct CacheValidationResponse: Codable, Sendable {
 	var invalidate: Bool
 	var updatedItems: Data?
 }

Spawn-App-iOS-SwiftUI/Models/DTOs/Calendar/CalendarActivityDTO.swift

@@ -1,7 +1,7 @@
 import Foundation
 import SwiftUI
 
-struct CalendarActivityDTO: Codable, Identifiable {
+struct CalendarActivityDTO: Codable, Identifiable, Sendable {
 	let id: UUID
 	let date: String  // ISO format: YYYY-MM-DD (matches backend)
 	let title: String?

Spawn-App-iOS-SwiftUI/Models/DTOs/CreateChatMessageDTO.swift

@@ -8,7 +8,8 @@
 import Foundation
 
 // Will correspond to `CreateChatMessageDTO` in the back-end:
-class CreateChatMessageDTO: Identifiable, Codable {
+struct CreateChatMessageDTO: Identifiable, Codable, Sendable {
+	var id: UUID = UUID()
 	var content: String
 	var senderUserId: UUID
 	var activityId: UUID

Spawn-App-iOS-SwiftUI/Models/DTOs/CreateReportedContentDTO.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-struct CreateReportedContentDTO: Codable {
+struct CreateReportedContentDTO: Codable, Sendable {
 	let reporterUserId: UUID
 	let contentId: UUID
 	let contentType: EntityType

Spawn-App-iOS-SwiftUI/Models/DTOs/Feedback/FeedbackSubmissionDTO.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct FetchFeedbackSubmissionDTO: Codable, Identifiable {
+struct FetchFeedbackSubmissionDTO: Codable, Identifiable, Sendable {
 	var id: UUID?
 	var type: FeedbackType
 	var fromUserId: UUID?

Spawn-App-iOS-SwiftUI/Models/DTOs/FetchReportedContentDTO.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-struct FetchReportedContentDTO: Codable, Identifiable {
+struct FetchReportedContentDTO: Codable, Identifiable, Sendable {
 	let id: UUID
 	let reporterUserId: UUID?
 	let reporterUsername: String?

Spawn-App-iOS-SwiftUI/Models/DTOs/FriendRequest/CreateFriendRequestDTO.swift

@@ -8,7 +8,7 @@
 import Foundation
 
 /// as defined in the back-end `CreateFriendRequestDTO.java`
-struct CreateFriendRequestDTO: Identifiable, Codable, Hashable {
+struct CreateFriendRequestDTO: Identifiable, Codable, Hashable, Sendable {
 	static func == (lhs: CreateFriendRequestDTO, rhs: CreateFriendRequestDTO) -> Bool {
 		return lhs.id == rhs.id
 	}

Spawn-App-iOS-SwiftUI/Models/DTOs/FriendRequest/FetchFriendRequestDTO.swift

@@ -8,7 +8,7 @@
 import Foundation
 
 /// as defined in the back-end `FetchFriendRequestDTO.java`
-struct FetchFriendRequestDTO: Identifiable, Codable, Hashable {
+struct FetchFriendRequestDTO: Identifiable, Codable, Hashable, Sendable {
 	static func == (lhs: FetchFriendRequestDTO, rhs: FetchFriendRequestDTO) -> Bool {
 		return lhs.id == rhs.id
 	}

Spawn-App-iOS-SwiftUI/Models/DTOs/FriendRequest/FetchSentFriendRequestDTO.swift

@@ -8,7 +8,7 @@
 import Foundation
 
 /// as defined in the back-end `FetchSentFriendRequestDTO.java`
-struct FetchSentFriendRequestDTO: Identifiable, Codable, Hashable {
+struct FetchSentFriendRequestDTO: Identifiable, Codable, Hashable, Sendable {
 	static func == (lhs: FetchSentFriendRequestDTO, rhs: FetchSentFriendRequestDTO) -> Bool {
 		return lhs.id == rhs.id
 	}

Spawn-App-iOS-SwiftUI/Models/DTOs/FullActivityChatMessageDTO.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-class FullActivityChatMessageDTO: Identifiable, Codable, Equatable {
+struct FullActivityChatMessageDTO: Identifiable, Codable, Equatable, Sendable {
 	var id: UUID
 	var content: String
 	var timestamp: Date
@@ -19,10 +19,6 @@ class FullActivityChatMessageDTO: Identifiable, Codable, Equatable {
 	// tech note: in user's view of activity, check if that user is in
 	// the `ChatMessage`'s `likedBy` array (`[User]`)
 
-	static func == (lhs: FullActivityChatMessageDTO, rhs: FullActivityChatMessageDTO) -> Bool {
-		return lhs.id == rhs.id
-	}
-
 	init(
 		id: UUID, content: String, timestamp: Date, senderUser: BaseUserDTO,
 		activityId: UUID, likedByUsers: [BaseUserDTO]? = nil

Spawn-App-iOS-SwiftUI/Models/DTOs/Notification/DeviceTokenDTO.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 /// Data transfer object for registering a device token with the backend
-struct DeviceTokenDTO: Codable {
+struct DeviceTokenDTO: Codable, Sendable {
 	/// The device token from APNS
 	let token: String
 

Spawn-App-iOS-SwiftUI/Models/DTOs/Notification/NotificationPreferencesDTO.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 /// Data transfer object for managing notification preferences
-struct NotificationPreferencesDTO: Codable {
+struct NotificationPreferencesDTO: Codable, Sendable {
 	/// Whether the user wants to receive friend request notifications
 	let friendRequestsEnabled: Bool
 

Spawn-App-iOS-SwiftUI/Models/DTOs/Notification/NotificationTypes.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 /// Defines all notification types used in the app
-enum NotificationType: String, Codable {
+enum NotificationType: String, Codable, Sendable {
 	/// Friend request notifications
 	case friendRequest = "friendRequest"
 
@@ -25,7 +25,7 @@ enum NotificationType: String, Codable {
 }
 
 /// Utility for building notification data
-struct NotificationDataBuilder {
+struct NotificationDataBuilder: Sendable {
 	/// Build notification data for a friend request
 	static func friendRequest(senderId: UUID, requestId: UUID) -> [String: String] {
 		return [