Support injectable custom TokenStore

Sources/AmoreLicensing/AmoreLicensing.swift

@@ -29,17 +29,19 @@ public final class AmoreLicensing: Licensing {
     ///   - bundleIdentifier: The app's bundle identifier. Defaults to `Bundle.main.bundleIdentifier`.
     ///   - configuration: The licensing configuration. Defaults to ``LicensingConfiguration/default``.
     ///   - server: The license server to use. Defaults to the Amore server.
+    ///   - tokenStore: A custom store for persisting the license token. Defaults to a ``FileTokenStore`` in Application Support. Provide a custom ``TokenStore`` to store the token elsewhere.
     public init(
         publicKey: String,
         bundleIdentifier: String? = nil,
         configuration: LicensingConfiguration = .default,
         server: LicenseServer? = nil,
+        tokenStore: (any TokenStore)? = nil
     ) throws {
         let bundleIdentifier = bundleIdentifier ?? Bundle.main.bundleIdentifier ?? publicKey
         self.configuration = configuration
         self.publicKey = try EdDSA.PublicKey(x: publicKey, curve: .ed25519)
         self.bundleIdentifier = bundleIdentifier
-        self.tokenStore = FileTokenStore(bundleIdentifier: bundleIdentifier)
+        self.tokenStore = tokenStore ?? FileTokenStore(bundleIdentifier: bundleIdentifier)
         self.hardwareIdentifier = MacHardwareIdentifier()
         self.licenseClient = HTTPLicenseClient(server: server ?? .amore(for: bundleIdentifier))
         if shouldAutoValidate {

Sources/AmoreLicensing/Documentation.docc/Index.md

@@ -32,6 +32,11 @@ AmoreLicensing provides an `@Observable` class that manages the full license lif
 - ``ValidationFrequency``
 - ``GracePeriod``
 
+### Token Storage
+
+- ``TokenStore``
+- ``FileTokenStore``
+
 ### Errors
 
 - ``AmoreError``

Sources/AmoreLicensing/TokenStore/FileTokenStore.swift

@@ -1,6 +1,10 @@
 import Foundation
 
-struct FileTokenStore: TokenStore {
+/// A ``TokenStore`` that persists the license token as a file on disk.
+///
+/// This is the default store used by ``AmoreLicensing`` when no custom store is provided. It writes
+/// to the app's Application Support directory.
+public struct FileTokenStore: TokenStore {
     private let fileURL: URL
 
     static let fileName = "license.jwt"
@@ -10,11 +14,13 @@ struct FileTokenStore: TokenStore {
         self.fileURL = appSupport.appendingPathComponent(bundleIdentifier).appendingPathComponent(Self.fileName)
     }
 
-    init(directory: URL) {
+    /// Creates a store that persists the token in the given directory.
+    /// - Parameter directory: The directory in which to read and write the token file.
+    public init(directory: URL) {
         self.fileURL = directory.appendingPathComponent(Self.fileName)
     }
 
-    func store(_ token: String) throws(TokenStoreError) {
+    public func store(_ token: String) throws(TokenStoreError) {
         let directory = fileURL.deletingLastPathComponent()
         do {
             try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
@@ -24,7 +30,7 @@ struct FileTokenStore: TokenStore {
         }
     }
 
-    func retrieve() throws(TokenStoreError) -> String? {
+    public func retrieve() throws(TokenStoreError) -> String? {
         guard FileManager.default.fileExists(atPath: fileURL.path(percentEncoded: false)) else { return nil }
         do {
             let data = try Data(contentsOf: fileURL)
@@ -34,7 +40,7 @@ struct FileTokenStore: TokenStore {
         }
     }
 
-    func delete() throws(TokenStoreError) {
+    public func delete() throws(TokenStoreError) {
         guard FileManager.default.fileExists(atPath: fileURL.path(percentEncoded: false)) else { return }
         do {
             try FileManager.default.removeItem(at: fileURL)

Sources/AmoreLicensing/TokenStore/TokenStore.swift

@@ -1,5 +1,21 @@
-protocol TokenStore: Sendable {
+/// A persistence mechanism for the signed license token.
+///
+/// `AmoreLicensing` uses a token store to persist the license JWT between launches so it can
+/// validate offline. The default ``FileTokenStore`` writes to Application Support. Provide a custom
+/// conformance to store the token elsewhere, and inject it via
+/// ``AmoreLicensing/init(publicKey:bundleIdentifier:configuration:server:tokenStore:)``.
+public protocol TokenStore: Sendable {
+    /// Persists the license token, replacing any previously stored token.
+    /// - Parameter token: The signed license JWT to store.
+    /// - Throws: ``TokenStoreError`` if the token cannot be written.
     func store(_ token: String) throws(TokenStoreError)
+
+    /// Returns the stored license token, or `nil` if none is stored.
+    /// - Returns: The stored license JWT, or `nil` when no token has been saved.
+    /// - Throws: ``TokenStoreError`` if a stored token exists but cannot be read.
     func retrieve() throws(TokenStoreError) -> String?
+
+    /// Removes the stored license token, if present.
+    /// - Throws: ``TokenStoreError`` if an existing token cannot be removed.
     func delete() throws(TokenStoreError)
 }