Update project to and fix compiler warnings for Xcode 9.3.

App/Composition/UploadImageAttachments.swift

@@ -86,7 +86,7 @@ private func uploadImages(fromSources sources: [ImageTag.Source], completion: @e
         if progress.isCancelled {
             completion(nil, NSError(domain: NSCocoaErrorDomain, code: NSUserCancelledError, userInfo: nil))
         } else {
-            completion(urls.flatMap { $0 }, nil)
+            completion(urls.compactMap { $0 }, nil)
         }
     }
 

App/Data Sources/ForumListDataSource.swift

@@ -319,7 +319,7 @@ extension ForumListDataSource: NSFetchedResultsControllerDelegate {
 extension ForumListDataSource: UITableViewDataSource {
     func numberOfSections(in tableView: UITableView) -> Int {
         return resultsControllers
-            .flatMap { $0.sections?.count }
+            .compactMap { $0.sections?.count }
             .reduce(0, +)
     }
 

App/In-App Actions/InAppActionCollectionViewLayout.swift

@@ -117,7 +117,7 @@ class InAppActionCollectionViewLayout: UICollectionViewLayout {
         return allAttributes.filter { rect.intersects($0.frame) }
     }
 
-    override func layoutAttributesForItem(at indexPath: IndexPath) -> (UICollectionViewLayoutAttributes!) {
+    override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
         return allAttributes[(indexPath as NSIndexPath).item]
     }
 

App/Misc/SystemCapabilities.swift

@@ -60,7 +60,7 @@ private func findModelIdentifier() throws -> String {
 
     let bufferSize = Int(size) + 1
     let buffer = UnsafeMutablePointer<CChar>.allocate(capacity: bufferSize)
-    defer { buffer.deallocate(capacity: bufferSize) }
+    defer { buffer.deallocate() }
 
     guard sysctlbyname("hw.machine", buffer, &size, nil, 0) == 0 else {
         throw ModelIdentifierError.failedToRetrieveModelIdentifier

App/Posts/PostsViewExternalStylesheetLoader.swift

@@ -52,7 +52,7 @@ final class PostsViewExternalStylesheetLoader: NSObject {
             request.setCacheHeadersWithResponse(oldResponse)
         }
 
-        session.downloadTask(with: request as URLRequest!, progress: nil, destination: { (targetPath, response) -> URL in
+        session.downloadTask(with: request, progress: nil, destination: { (targetPath, response) -> URL in
             self.createCacheFolderIfNecessary()
             return self.cachedStylesheetURL
 

App/Posts/ReportPostViewController.swift

@@ -96,7 +96,7 @@ final class ReportPostViewController: ViewController {
         rootView.instructionLabel.textColor = theme["listTextColor"] as UIColor?
         rootView.commentTextField.textColor = theme["listTextColor"] as UIColor?
         rootView.commentTextField.attributedPlaceholder = NSAttributedString(string: "Optional comment", attributes: [
-            .foregroundColor: theme["placeholderTextColor"] as UIColor!])
+            .foregroundColor: theme["placeholderTextColor"] as UIColor? ?? .black])
     }
 
     override func viewWillAppear(_ animated: Bool) {

App/Private Messages/MessageComposeViewController.swift

@@ -93,7 +93,7 @@ final class MessageComposeViewController: ComposeTextViewController {
             .then { [weak self] (threadTags) -> Void in
                 self?.availableThreadTags = threadTags
 
-                let imageNames = [ThreadTagLoader.emptyPrivateMessageImageName] + threadTags.flatMap { $0.imageName }
+                let imageNames = [ThreadTagLoader.emptyPrivateMessageImageName] + threadTags.compactMap { $0.imageName }
                 let picker = ThreadTagPickerViewController(imageNames: imageNames, secondaryImageNames: nil)
                 picker.delegate = self
                 picker.navigationItem.leftBarButtonItem = picker.cancelButtonItem

App/Settings/AppIconPickerCell.swift

@@ -67,7 +67,7 @@ final class AppIconPickerCell: UITableViewCell, UICollectionViewDataSource, UICo
         let oldSelectedIndexPath = appIcons
             .index { $0.iconName == previousSelection }
             .map { IndexPath(item: $0, section: 0) }
-        let reloadIndexPaths = [indexPath, oldSelectedIndexPath].flatMap { $0 }
+        let reloadIndexPaths = [indexPath, oldSelectedIndexPath].compactMap { $0 }
         collectionView.reloadItems(at: reloadIndexPaths)
     }
 }
@@ -117,9 +117,9 @@ private func findAppIcons() -> [AppIcon] {
 
     let alternates = icons["CFBundleAlternateIcons"] as? [String: Any] ?? [:]
     let alternateFilenames = alternates.values
-        .flatMap { (value: Any) -> [String: Any]? in value as? [String: Any] }
-        .flatMap { (dict: [String: Any]) -> [String]? in dict["CFBundleIconFiles"] as? [String] }
-        .flatMap { (files: [String]) -> String? in files.first(where: filenameContainsHandySize) }
+        .compactMap { (value: Any) -> [String: Any]? in value as? [String: Any] }
+        .compactMap { (dict: [String: Any]) -> [String]? in dict["CFBundleIconFiles"] as? [String] }
+        .compactMap { (files: [String]) -> String? in files.first(where: filenameContainsHandySize) }
         .sorted { (lhs: String, rhs: String) -> Bool in lhs.caseInsensitiveCompare(rhs) == .orderedAscending }
 
     var filenames = [primaryFilename]

App/Thread Tags/ThreadTagLoader.swift

@@ -230,7 +230,7 @@ final class ThreadTagLoader: NSObject {
         guard let shippedThreadTagFolder = Bundle(for: ThreadTagLoader.self).resourceURL?.appendingPathComponent(resourceSubfolder, isDirectory: true) else { return placeholderImageNames }
         do {
             let URLs = try FileManager.default.contentsOfDirectory(at: shippedThreadTagFolder, includingPropertiesForKeys: nil, options: .skipsHiddenFiles)
-            return URLs.flatMap { $0.lastPathComponent } + placeholderImageNames
+            return URLs.compactMap { $0.lastPathComponent } + placeholderImageNames
         } catch {
             print("\(#function) error listing shipped thread tags: \(error)")
             return placeholderImageNames
@@ -240,7 +240,7 @@ final class ThreadTagLoader: NSObject {
     fileprivate var cachedThreadTagImageNames: [String] {
         do {
             let URLs = try FileManager.default.contentsOfDirectory(at: cacheFolder, includingPropertiesForKeys: nil, options: .skipsHiddenFiles)
-            return URLs.flatMap { $0.lastPathComponent }
+            return URLs.compactMap { $0.lastPathComponent }
         } catch {
             print("\(#function) error listing cached thread tags: \(error)")
             return []

App/Threads/ThreadComposeViewController.swift

@@ -157,8 +157,8 @@ final class ThreadComposeViewController: ComposeTextViewController {
                 sself.availableSecondaryThreadTags = tags.secondary
                 guard let tags = sself.availableThreadTags else { return }
 
-                let imageNames = [ThreadTagLoader.emptyThreadTagImageName] + tags.flatMap { $0.imageName }
-                let secondaryImageNames = sself.availableSecondaryThreadTags?.flatMap { $0.imageName }
+                let imageNames = [ThreadTagLoader.emptyThreadTagImageName] + tags.compactMap { $0.imageName }
+                let secondaryImageNames = sself.availableSecondaryThreadTags?.compactMap { $0.imageName }
                 let picker = ThreadTagPickerViewController(imageNames: imageNames, secondaryImageNames: secondaryImageNames)
                 sself.threadTagPicker = picker
                 picker.delegate = sself

App/URLs/AwfulURLRouter.swift

@@ -187,7 +187,7 @@ final class AwfulURLRouter: NSObject {
      */
     func route(_ url: URL) -> Bool {
         guard url.scheme?.caseInsensitiveCompare("awful") == .orderedSame else { return false }
-        return routes.routeURL(url as URL!)
+        return routes.routeURL(url)
     }
 
     fileprivate func jumpToForum(_ forum: Forum) -> Bool {

App/URLs/ResourceURLProtocol.swift

@@ -34,7 +34,7 @@ final class ResourceURLProtocol: URLProtocol {
         let possibleResourceURLs = resource
             .pathsForScreenWithScale(UIScreen.main.scale)
             .map { Bundle.main.url(forResource: $0, withExtension: nil) }
-            .flatMap { $0 }
+            .compactMap { $0 }
 
         guard let resourceURL = possibleResourceURLs.first else {
             print("Could not find resource for URL \(URL)")

App/View Controllers/ThreadsTableViewController.swift

@@ -329,7 +329,7 @@ final class ThreadsTableViewController: TableViewController, ComposeTextViewCont
     // MARK: UIViewControllerRestoration
 
     class func viewController(withRestorationIdentifierPath identifierComponents: [Any], coder: NSCoder) -> UIViewController? {
-        var forumKey = coder.decodeObject(forKey: RestorationKeys.forumKey) as! ForumKey!
+        var forumKey = coder.decodeObject(forKey: RestorationKeys.forumKey) as! ForumKey?
         if forumKey == nil {
             guard let forumID = coder.decodeObject(forKey: ObsoleteRestorationKeys.forumID) as? String else { return nil }
             forumKey = ForumKey(forumID: forumID)

Awful.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

Core/Model/AwfulManagedObject.swift

@@ -62,8 +62,8 @@ public class AwfulObjectKey: NSObject, NSCoding, NSCopying {
                 return false
             }
             for key in keys {
-                let otherValue = other.value(forKey: key) as! NSObject!
-                let value = self.value(forKey: key) as! NSObject!
+                let otherValue = other.value(forKey: key) as! NSObject?
+                let value = self.value(forKey: key) as! NSObject?
                 if otherValue != nil && value != nil && otherValue != value {
                     return false
                 }
@@ -141,7 +141,7 @@ extension AwfulManagedObject {
     }
 
     public class func objectForKey(objectKey: AwfulObjectKey, inManagedObjectContext context: NSManagedObjectContext) -> AnyObject {
-        var object = existingObjectForKey(objectKey: objectKey, inManagedObjectContext: context) as! AwfulManagedObject!
+        var object = existingObjectForKey(objectKey: objectKey, inManagedObjectContext: context) as! AwfulManagedObject?
         if object == nil {
             object = insertIntoManagedObjectContext(context: context)
         }

Core/Networking/ForumsClient.swift

@@ -75,7 +75,7 @@ public final class ForumsClient {
 
         context.perform {
             updatedObjectIDs
-                .flatMap { context.object(with: $0) }
+                .compactMap { context.object(with: $0) }
                 .forEach { $0.willAccessValue(forKey: nil) }
 
             context.mergeChanges(fromContextDidSave: notification)
@@ -194,7 +194,7 @@ public final class ForumsClient {
                 return forums.map { $0.objectID }
             }
             .then(on: mainContext) { objectIDs, context -> [Forum] in
-                return objectIDs.flatMap { context.object(with: $0) as? Forum }
+                return objectIDs.compactMap { context.object(with: $0) as? Forum }
         }
     }
 
@@ -237,7 +237,7 @@ public final class ForumsClient {
                 return threads.map { $0.objectID }
             }
             .then(on: mainContext) { objectIDs, context -> [AwfulThread] in
-                return objectIDs.flatMap { context.object(with: $0) as? AwfulThread }
+                return objectIDs.compactMap { context.object(with: $0) as? AwfulThread }
         }
     }
 
@@ -275,7 +275,7 @@ public final class ForumsClient {
                 return threads.map { $0.objectID }
             }
             .then(on: mainContext) { objectIDs, context -> [AwfulThread] in
-                return objectIDs.flatMap { context.object(with: $0) as? AwfulThread }
+                return objectIDs.compactMap { context.object(with: $0) as? AwfulThread }
         }
     }
 
@@ -359,8 +359,8 @@ public final class ForumsClient {
             }
             .then(on: mainContext) { objectIDs, context -> (primary: [ThreadTag], secondary: [ThreadTag]) in
                 return (
-                    primary: objectIDs.primary.flatMap { context.object(with: $0) as? ThreadTag },
-                    secondary: objectIDs.secondary.flatMap { context.object(with: $0) as? ThreadTag })
+                    primary: objectIDs.primary.compactMap { context.object(with: $0) as? ThreadTag },
+                    secondary: objectIDs.secondary.compactMap { context.object(with: $0) as? ThreadTag })
         }
     }
 
@@ -523,7 +523,7 @@ public final class ForumsClient {
                 return announcements.map { $0.objectID }
             }
             .then(on: mainContext) { objectIDs, context -> [Announcement] in
-                return objectIDs.flatMap { context.object(with: $0) as? Announcement }
+                return objectIDs.compactMap { context.object(with: $0) as? Announcement }
         }
 
         return (promise: result, cancellable: cancellable)
@@ -592,7 +592,7 @@ public final class ForumsClient {
                 return posts.map { $0.objectID }
             }
             .then(on: mainContext) { objectIDs, context -> [Post] in
-                return objectIDs.flatMap { context.object(with: $0) as? Post }
+                return objectIDs.compactMap { context.object(with: $0) as? Post }
             }
 
         let firstUnreadPostIndex = promise
@@ -1066,7 +1066,7 @@ public final class ForumsClient {
                 return messages.map { $0.objectID }
             }
             .then(on: mainContext) { (objectIDs, context) -> [PrivateMessage] in
-                return objectIDs.flatMap { context.object(with: $0) as? PrivateMessage }
+                return objectIDs.compactMap { context.object(with: $0) as? PrivateMessage }
         }
     }
 
@@ -1145,7 +1145,7 @@ public final class ForumsClient {
                 return managed.primary.map { $0.objectID }
             }
             .then(on: mainContext) { managedObjectIDs, context -> [ThreadTag] in
-                return managedObjectIDs.flatMap { context.object(with: $0) as? ThreadTag }
+                return managedObjectIDs.compactMap { context.object(with: $0) as? ThreadTag }
         }
     }
 

Core/Persistence/AnnouncementPersistence.swift

@@ -20,7 +20,7 @@ internal extension AnnouncementListScrapeResult {
         do {
             let request = NSFetchRequest<User>(entityName: User.entityName())
             let usernames: [String] = self.announcements
-                .flatMap { (announcement: Announcement) -> String? in announcement.author?.username }
+                .compactMap { (announcement: Announcement) -> String? in announcement.author?.username }
                 .filter { (s: String) -> Bool in !s.isEmpty }
             request.predicate = NSPredicate(format: "%K IN %@", #keyPath(User.username), usernames)
             request.returnsObjectsAsFaults = false
@@ -84,7 +84,7 @@ internal extension ThreadListScrapeResult {
         var threadTags: [String: ThreadTag] = [:]
         do {
             let request = NSFetchRequest<ThreadTag>(entityName: ThreadTag.entityName())
-            let imageNames = self.announcements.flatMap { $0.iconURL }.flatMap(ThreadTag.imageName)
+            let imageNames = self.announcements.compactMap { $0.iconURL }.flatMap(ThreadTag.imageName)
             request.predicate = NSPredicate(format: "%K in %@", #keyPath(ThreadTag.imageName), imageNames)
             request.returnsObjectsAsFaults = false
 
@@ -97,7 +97,7 @@ internal extension ThreadListScrapeResult {
         var users: [UserID: User] = [:]
         do {
             let request = NSFetchRequest<User>(entityName: User.entityName())
-            let userIDs = self.announcements.flatMap { $0.author }.map { $0.rawValue }
+            let userIDs = self.announcements.compactMap { $0.author }.map { $0.rawValue }
             request.predicate = NSPredicate(format: "%K in %@", #keyPath(User.userID), userIDs)
             request.returnsObjectsAsFaults = false
 

Core/Persistence/ForumPersistence.swift

@@ -51,7 +51,7 @@ internal extension ForumBreadcrumbsScrapeResult {
             unorderedForums[rawForum.id] = forum
         }
 
-        let forums = rawForums.flatMap { (raw) -> Forum? in
+        let forums = rawForums.compactMap { (raw) -> Forum? in
             let forum = unorderedForums[raw.id]
             if let forum = forum { raw.update(forum) }
             return forum

Core/Persistence/PostIconPersistence.swift

@@ -40,7 +40,7 @@ internal class PostIconPersistenceHelper {
             .map { $0.id }
             .filter { !$0.isEmpty }
         let imageNames = icons
-            .flatMap { $0.url }
+            .compactMap { $0.url }
             .map(ThreadTag.imageName)
             .filter { !$0.isEmpty }
         request.predicate = NSCompoundPredicate(orPredicateWithSubpredicates: [

Core/Persistence/PrivateMessagePersistence.swift

@@ -23,7 +23,7 @@ internal extension PrivateMessageFolderScrapeResult {
         do {
             let request = NSFetchRequest<ThreadTag>(entityName: ThreadTag.entityName())
             let imageNames = self.messages
-                .flatMap { $0.iconImage }
+                .compactMap { $0.iconImage }
                 .map { $0.deletingPathExtension().lastPathComponent }
             request.predicate = NSPredicate(format: "%K IN %@", #keyPath(ThreadTag.imageName), imageNames)
             request.returnsObjectsAsFaults = false

Core/Persistence/ThreadPersistence.swift

@@ -9,8 +9,8 @@ internal extension ThreadListScrapeResult {
         let (group: _, forums: forums) = try breadcrumbs?.upsert(into: context) ?? (nil, [])
         let forum = forums.last
 
-        let icons = self.threads.flatMap { $0.icon }
-            + self.threads.flatMap { $0.secondaryIcon }
+        let icons = self.threads.compactMap { $0.icon }
+            + self.threads.compactMap { $0.secondaryIcon }
             + self.filterableIcons
         let iconHelper = PostIconPersistenceHelper(context: context, icons: icons)
         try iconHelper.performFetch()
@@ -22,7 +22,7 @@ internal extension ThreadListScrapeResult {
         var users: [UserID: User] = [:]
         do {
             let request = NSFetchRequest<User>(entityName: User.entityName())
-            let userIDs = self.threads.flatMap { $0.author?.rawValue }
+            let userIDs = self.threads.compactMap { $0.author?.rawValue }
             request.predicate = NSPredicate(format: "%K IN %@", #keyPath(User.userID), userIDs)
             request.returnsObjectsAsFaults = false
 

Core/Scraping/Form.swift

@@ -325,7 +325,7 @@ private func scrapeSubmissionStringEncoding(document: HTMLDocument?, form: HTMLE
         .components(separatedBy: asciiWhitespace)
         .map(StringEncodingForLabel)
         .filter { $0 != InvalidStringEncoding() }
-        .flatMap(String.Encoding.init)
+        .compactMap(String.Encoding.init)
         .first
 }
 

Core/Scraping/ForumHierarchyScrapeResult.swift

@@ -11,7 +11,7 @@ public struct ForumHierarchyScrapeResult: ScrapeResult {
         let select = try html.requiredNode(matchingSelector: "select[name = 'forumid']")
         nodes = try select
             .nodes(matchingSelector: "option[value]")
-            .flatMap(ForumHierarchyNode.init)
+            .compactMap(ForumHierarchyNode.init)
     }
 }
 

Core/Scraping/LepersColonyScrapeResult.swift

@@ -63,7 +63,7 @@ public struct LepersColonyScrapeResult: ScrapeResult {
 
     public init(_ html: HTMLNode, url: URL?) throws {
         let table = try html.requiredNode(matchingSelector: "table.standard")
-        punishments = table.nodes(matchingSelector: "tr").flatMap { try? Punishment($0) }
+        punishments = table.nodes(matchingSelector: "tr").compactMap { try? Punishment($0) }
     }
 }
 

Core/Scraping/PostIconListScrapeResult.swift

@@ -17,7 +17,7 @@ public struct PostIconListScrapeResult: ScrapeResult {
             throw ScrapingError.missingExpectedElement("div.posticon")
         }
 
-        primaryIcons = primaryDivs.flatMap { try? PostIcon(div: $0) }
+        primaryIcons = primaryDivs.compactMap { try? PostIcon(div: $0) }
 
         selectedPrimaryIconFormName = try primaryDivs.first!
             .requiredNode(matchingSelector: "input[name]")["name"]!
@@ -30,7 +30,7 @@ public struct PostIconListScrapeResult: ScrapeResult {
             return
         }
 
-        secondaryIcons = zip(secondaryInputs, secondaryImages).flatMap {
+        secondaryIcons = zip(secondaryInputs, secondaryImages).compactMap {
             try? PostIcon(input: $0, image: $1)
         }
 

Core/Scraping/PrivateMessageFolderScrapeResult.swift

@@ -33,7 +33,7 @@ public struct PrivateMessageFolderScrapeResult: ScrapeResult {
 
         allFolders = folderDropdown?
             .nodes(matchingSelector: "option[value]")
-            .flatMap { try? Folder($0) }
+            .compactMap { try? Folder($0) }
             ?? []
 
         folder = folderDropdown
@@ -47,7 +47,7 @@ public struct PrivateMessageFolderScrapeResult: ScrapeResult {
 
         messages = try html.requiredNode(matchingSelector: "table.standard")
             .nodes(matchingSelector: "tbody tr")
-            .flatMap { try? Message($0) }
+            .compactMap { try? Message($0) }
     }
 }