Improve handling of Bitrise token editing (#42)

Tophat/Utilities/CachingApplicationDownloader.swift

@@ -74,8 +74,18 @@ actor CachingApplicationDownloader: ApplicationDownloading {
 			return application
 		}
 
-		downloads[source] = Download(container: container, task: task)
-		return try await task.value
+		let download = Download(container: container, task: task)
+		downloads[source] = download
+
+		do {
+			return try await task.value
+		} catch {
+			// If the download failed, do not cache it.
+			try? await download.container.delete()
+			downloads[source] = nil
+
+			throw error
+		}
 	}
 
 	/// Deletes all cached data that was tracked by this instance.

TophatExtensions/TophatBitriseExtension/Settings/SettingsView.swift

@@ -10,9 +10,8 @@ import SwiftUI
 import TophatKit
 
 struct SettingsView: View {
-	@SecureStorage(Constants.keychainPersonalAccessTokenKey) var personalAccessToken: String?
-
-	@State private var enteredPersonalAccessToken: String = ""
+	@SecureStorage(Constants.keychainPersonalAccessTokenKey) var storedPersonalAccessToken: String?
+	@State private var enteredPersonalAccessToken = ""
 
 	var body: some View {
 		Form {
@@ -26,10 +25,10 @@ struct SettingsView: View {
 		}
 		.formStyle(.grouped)
 		.onAppear {
-			enteredPersonalAccessToken = personalAccessToken ?? ""
+			enteredPersonalAccessToken = storedPersonalAccessToken ?? ""
 		}
-		.onDisappear {
-			personalAccessToken = enteredPersonalAccessToken
+		.onChange(of: enteredPersonalAccessToken, initial: false) { oldValue, newValue in
+			storedPersonalAccessToken = newValue.isEmpty ? nil : newValue
 		}
 	}
 }

TophatExtensions/TophatBitriseExtension/Utilities/SecureStorage.swift

@@ -7,39 +7,27 @@
 //
 
 import SwiftUI
-import Observation
 import SimpleKeychain
 
 @propertyWrapper
-public struct SecureStorage: DynamicProperty {
+struct SecureStorage {
 	private let key: String
 	private let keychain = SimpleKeychain()
 
-	@State private var value: String?
-
 	public init(_ key: String) {
 		self.key = key
-		self._value = State(initialValue: try? keychain.string(forKey: key))
 	}
 
 	public var wrappedValue: String? {
-		get { value }
+		get {
+			try? keychain.string(forKey: key)
+		}
 		nonmutating set {
 			if let newValue {
 				try? keychain.set(newValue, forKey: key)
 			} else {
 				try? keychain.deleteItem(forKey: key)
 			}
-
-			value = newValue
-		}
-	}
-
-	public var projectedValue: Binding<String?> {
-		Binding {
-			wrappedValue
-		} set: { newValue in
-			wrappedValue = newValue
 		}
 	}
 }