[AltServer] Improves error messages

AltServer/AppDelegate.swift

@@ -139,7 +139,7 @@ private extension AppDelegate
                 switch result
                 {
                 case .failure(let error):
-                    self.showErrorAlert(title: String(format: NSLocalizedString("JIT compilation could not be enabled for %@.", comment: ""), app.name), error: error)
+                    self.showErrorAlert(error: error, localizedFailure: String(format: NSLocalizedString("JIT compilation could not be enabled for %@.", comment: ""), app.name))
                     
                 case .success:
                     let alert = NSAlert()
@@ -234,28 +234,8 @@ private extension AppDelegate
                     // Ignore
                     break
                     
-                case .failure(let error as NSError):
-                    
-                    let alert = NSAlert()
-                    alert.alertStyle = .critical
-                    alert.messageText = NSLocalizedString("Installation Failed", comment: "")
-                    
-                    if let underlyingError = error.userInfo[NSUnderlyingErrorKey] as? Error
-                    {
-                        alert.informativeText = underlyingError.localizedDescription
-                    }
-                    else if let recoverySuggestion = error.localizedRecoverySuggestion
-                    {
-                        alert.informativeText = error.localizedDescription + "\n\n" + recoverySuggestion
-                    }
-                    else
-                    {
-                        alert.informativeText = error.localizedDescription
-                    }
-                    
-                    NSRunningApplication.current.activate(options: .activateIgnoringOtherApps)
-
-                    alert.runModal()
+                case .failure(let error):
+                    self.showErrorAlert(error: error, localizedFailure: String(format: NSLocalizedString("Could not install app to %@.", comment: ""), device.name))
                 }
             }
         }
@@ -289,6 +269,67 @@ private extension AppDelegate
         }
     }
     
+    func showErrorAlert(error: Error, localizedFailure: String)
+    {
+        let nsError = error as NSError
+        
+        let alert = NSAlert()
+        alert.alertStyle = .critical
+        alert.messageText = localizedFailure
+        
+        var messageComponents = [String]()
+        
+        if let errorFailure = nsError.localizedFailure
+        {
+            if let failureReason = nsError.localizedFailureReason
+            {
+                if nsError.localizedDescription.starts(with: errorFailure)
+                {
+                    alert.messageText = errorFailure
+                    messageComponents.append(failureReason)
+                }
+                else
+                {
+                    alert.messageText = errorFailure
+                    messageComponents.append(nsError.localizedDescription)
+                }
+            }
+            else
+            {
+                // No failure reason given.
+                
+                if nsError.localizedDescription.starts(with: errorFailure)
+                {
+                    // No need to duplicate errorFailure in both title and message.
+                    alert.messageText = localizedFailure
+                    messageComponents.append(nsError.localizedDescription)
+                }
+                else
+                {
+                    alert.messageText = errorFailure
+                    messageComponents.append(nsError.localizedDescription)
+                }
+            }
+        }
+        else
+        {
+            alert.messageText = localizedFailure
+            messageComponents.append(nsError.localizedDescription)
+        }
+        
+        if let recoverySuggestion = nsError.localizedRecoverySuggestion
+        {
+            messageComponents.append(recoverySuggestion)
+        }
+        
+        let informativeText = messageComponents.joined(separator: " ")
+        alert.informativeText = informativeText
+        
+        NSRunningApplication.current.activate(options: .activateIgnoringOtherApps)
+
+        alert.runModal()
+    }
+    
     @objc func toggleLaunchAtLogin(_ item: NSMenuItem)
     {
         LaunchAtLogin.isEnabled.toggle()

AltServer/Devices/ALTDeviceManager+Installation.swift

@@ -38,10 +38,22 @@ extension ALTDeviceManager
     {
         let destinationDirectoryURL = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
         
+        var appName = (url.isFileURL) ? url.deletingPathExtension().lastPathComponent : NSLocalizedString("AltStore", comment: "")
+        
         func finish(_ result: Result<ALTApplication, Error>, title: String = "")
         {
             DispatchQueue.main.async {
-                completion(result)
+                switch result
+                {
+                case .success(let app): completion(.success(app))
+                case .failure(var error as NSError):
+                    if error.localizedFailure == nil
+                    {
+                        error = error.withLocalizedFailure(String(format: NSLocalizedString("Could not install %@ to %@.", comment: ""), appName, altDevice.name))
+                    }
+                    
+                    completion(.failure(error))
+                }
             }
             
             try? FileManager.default.removeItem(at: destinationDirectoryURL)

AltServer/Devices/ALTDeviceManager.mm

@@ -1126,6 +1126,11 @@ NSNotificationName const ALTDeviceManagerDeviceDidDisconnectNotification = @"ALT
             idevice_free(device);
         }
         
+        if (error)
+        {
+            error = [error alt_errorWithLocalizedFailure:[NSString stringWithFormat:NSLocalizedString(@"The Developer disk image could not be installed onto %@.", @""), altDevice.name]];
+        }
+        
         completionHandler(error == nil, error);
     };