Add property wrapper

Package.swift

@@ -23,5 +23,8 @@ let package = Package(
         .target(
             name: "KeychainUtility",
             dependencies: []),
+        .testTarget(
+            name: "KeychainUtilityTests",
+            dependencies: ["KeychainUtility"]),
     ]
 )

README.md

@@ -2,6 +2,23 @@
 
 Keychain Utility is a wrapper to help you interact with the Keychain APIs in an easier way
 
+# Usage
+Add `@KeychainStorage` annotation in the properties you want to store into the keychain (or read from it). Provide a `Key` and an `ItemType` (you can check the list [here](https://blorenzo10.github.io/keychain-utility/documentation/keychainutility/itemclass))
+
+```swift
+@KeychainStorage(key: "API-Token", itemClass: .generic)
+var token: String?
+
+// It will print the current value
+print(token)
+
+// Update item
+token = "c0c61d55558b0c8dac82a16c04981eea7c99e37d714367e575028221028b0d4cff122d6a7556fc0ab1c66d1d4b05b378"
+
+// Delete item
+token = nil 
+```
+
 # Documentation
 
 Check [Keychain Utility Documentation Page](https://blorenzo10.github.io/keychain-utility/documentation/keychainutility/) for more info.

Sources/KeychainUtility/KeychainManager.swift

@@ -3,13 +3,15 @@ import Foundation
 /// Manager with all the necessary methods to interact with the keychain
 public class KeychainManager {
 
-    /// Shared instance to access the manager
-    public static let shared = KeychainManager()
+    private var attributes: ItemAttributes?
 
-    public typealias KeychainDictionary = [String : Any]
-    public typealias ItemAttributes = [CFString : Any]
+    public class var standard: KeychainManager {
+        return KeychainManager()
+    }
 
-    private init() {}
+    public init(attributes: ItemAttributes? = nil) {
+        self.attributes = attributes
+    }
 
     /// Save any Encodable data into the keychain
     ///
@@ -31,8 +33,7 @@ public class KeychainManager {
     /// - Parameter itemClass: The item class
     /// - Parameter key: Key to identifiy the item
     /// - Parameter attributes: Optional dictionary with attributes to narrow the search
-    public func saveItem<T: Encodable>(_ item: T, itemClass: ItemClass, key: String, attributes: ItemAttributes? = nil) throws {
-
+    public func saveItem<T: Encodable>(_ item: T, itemClass: ItemClass, key: String) throws {
         let itemData = try JSONEncoder().encode(item)
         var query: KeychainDictionary = [
             kSecClass as String: itemClass.rawValue,
@@ -69,7 +70,7 @@ public class KeychainManager {
     /// - Parameter key: Key to identifiy the item
     /// - Parameter attributes: Optional dictionary with attributes to narrow the search
     /// - Returns: An instance of type `T`
-    public func retrieveItem<T: Decodable>(ofClass itemClass: ItemClass, key: String, attributes: ItemAttributes? = nil) throws -> T {
+    public func retrieveItem<T: Decodable>(ofClass itemClass: ItemClass, key: String) throws -> T {
         var query: KeychainDictionary = [
             kSecClass as String: itemClass.rawValue,
             kSecAttrAccount as String: key as AnyObject,
@@ -113,7 +114,7 @@ public class KeychainManager {
     /// - Parameter itemClass: The item class
     /// - Parameter key: Key to identifiy the item
     /// - Parameter attributes: Optional dictionary with attributes to narrow the search
-    public func updateItem<T: Encodable>(with item: T, ofClass itemClass: ItemClass, key: String, attributes: ItemAttributes? = nil) throws {
+    public func updateItem<T: Encodable>(with item: T, ofClass itemClass: ItemClass, key: String) throws {
         var query: KeychainDictionary = [
             kSecClass as String: itemClass.rawValue,
             kSecAttrAccount as String: key as AnyObject,
@@ -153,7 +154,7 @@ public class KeychainManager {
     /// - Parameter itemClass: The item class
     /// - Parameter key: Key to identifiy the item
     /// - Parameter attributes: Optional dictionary with attributes to narrow the search
-    public func deleteItem(ofClass itemClass: ItemClass, key: String, attributes: ItemAttributes? = nil) throws {
+    public func deleteItem(ofClass itemClass: ItemClass, key: String) throws {
         var query: KeychainDictionary = [
             kSecClass as String: itemClass.rawValue,
             kSecAttrAccount as String: key as AnyObject
@@ -188,13 +189,3 @@ private extension KeychainManager {
     }
 
 }
-
-// MARK: - Dictionary
-
-extension KeychainManager.KeychainDictionary {
-    mutating func addAttributes(_ attributes: KeychainManager.ItemAttributes) {
-        for(key, value) in attributes {
-            self[key as String] = value
-        }
-    }
-}

Sources/KeychainUtility/KeychainStorage.swift

@@ -0,0 +1,73 @@
+import Foundation
+
+@propertyWrapper
+public struct KeychainStorage<T: Codable> {
+    let key: String
+    let itemClass: ItemClass
+    let keychain: KeychainManager
+
+    private var currentValue: T?
+
+    public var wrappedValue: T? {
+        get {
+            return getItem()
+        }
+
+        set {
+            if let newValue {
+                getItem() != nil
+                    ? updateItem(newValue)
+                    : saveItem(newValue)
+            } else {
+                deleteItem()
+            }
+        }
+    }
+
+    public init(key: String, itemClass: ItemClass, keychain: KeychainManager = .standard) {
+        self.key = key
+        self.itemClass = itemClass
+        self.keychain = keychain
+    }
+}
+
+// MARK: - Helpers
+private extension KeychainStorage {
+
+    func getItem() -> T? {
+        do {
+            return try keychain.retrieveItem(ofClass: itemClass, key: key)
+        } catch {
+            handleError(error)
+        }
+        return nil
+    }
+
+    func saveItem(_ item: T) {
+        do {
+            try keychain.saveItem(item, itemClass: itemClass, key: key)
+        } catch {
+            handleError(error)
+        }
+    }
+
+    func updateItem(_ item: T) {
+        do {
+            try keychain.updateItem(with: item, ofClass: itemClass, key: key)
+        } catch {
+            handleError(error)
+        }
+    }
+
+    func deleteItem() {
+        do {
+            try keychain.deleteItem(ofClass: itemClass, key: key)
+        } catch {
+            handleError(error)
+        }
+    }
+
+    func handleError(_ error: Error) {
+        print(error)
+    }
+}

Sources/KeychainUtility/KeychainUtils.swift

@@ -0,0 +1,19 @@
+//
+//  File.swift
+//  
+//
+//  Created by Bruno Lorenzo on 5/10/23.
+//
+
+import Foundation
+
+public typealias KeychainDictionary = [String : Any]
+public typealias ItemAttributes = [CFString : Any]
+
+extension KeychainDictionary {
+    mutating func addAttributes(_ attributes: ItemAttributes) {
+        for(key, value) in attributes {
+            self[key as String] = value
+        }
+    }
+}

Tests/KeychainUtilityTests/PropertyWrapperTests.swift

@@ -0,0 +1,47 @@
+
+import Foundation
+import XCTest
+@testable import KeychainUtility
+
+final class PropertyWrapperTests: XCTestCase {
+
+    @KeychainStorage(key: "API-Token", itemClass: .generic)
+    var token: String?
+
+    override func setUp() {
+        super.setUp()
+    }
+
+    override func tearDown() {
+        super.tearDown()
+        token = nil
+    }
+
+    func testSaveItem() {
+        token = "c0c61d55558b0c8dac82a16c04981eea7c99e37d714367e575028221028b0d4cff122d6a7556fc0ab1c66d1d4b05b378"
+        let keychainToken: String? = try? KeychainManager.standard.retrieveItem(ofClass: .generic, key: "API-Token")
+        XCTAssertEqual(token, keychainToken)
+    }
+
+    func testUpdateItem() {
+        token = "c0c61d55558b0c8dac82a16c04981eea7c99e37d714367e575028221028b0d4cff122d6a7556fc0ab1c66d1d4b05b378"
+        var keychainToken: String? = try? KeychainManager.standard.retrieveItem(ofClass: .generic, key: "API-Token")
+        XCTAssertEqual(token, keychainToken)
+
+        token = "b7bb1d55558b0c8dac82a16c04981eea7c99e37d714367e575028221028b0d4cff122d6a7556fc0ab1c66d1d4b05b378"
+        XCTAssertNotEqual(token, keychainToken)
+
+        keychainToken = try? KeychainManager.standard.retrieveItem(ofClass: .generic, key: "API-Token")
+        XCTAssertEqual(token, keychainToken)
+    }
+
+    func testRemoveItem() {
+        token = "c0c61d55558b0c8dac82a16c04981eea7c99e37d714367e575028221028b0d4cff122d6a7556fc0ab1c66d1d4b05b378"
+        var keychainToken: String? = try? KeychainManager.standard.retrieveItem(ofClass: .generic, key: "API-Token")
+        XCTAssertEqual(token, keychainToken)
+
+        token = nil
+        keychainToken = try? KeychainManager.standard.retrieveItem(ofClass: .generic, key: "API-Token")
+        XCTAssertNil(token)
+    }
+}