Add defaultFileStatePath

Sources/AppState/Application/Application+public.swift

@@ -1070,7 +1070,7 @@ public extension Application {
      */
     func fileState<Value>(
         initial: @escaping @autoclosure () -> Value,
-        path: String = "~/App",
+        path: String = FileManager.defaultFileStatePath,
         filename: String
     ) -> FileState<Value> {
         FileState(
@@ -1088,7 +1088,7 @@ public extension Application {
      - Returns: The state of type `Value`.
      */
     func fileState<Value>(
-        path: String = "~/App",
+        path: String = FileManager.defaultFileStatePath,
         filename: String
     ) -> FileState<Value?> {
         fileState(

Sources/AppState/Application/Types/Helper/FileManager+AppState.swift

@@ -7,6 +7,22 @@ extension FileManager {
         var errorDescription: String? { rawValue }
     }
 
+    public static var defaultFileStatePath: String {
+        guard let path = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
+            return "~/App"
+        }
+
+        #if !os(Linux) && !os(Windows)
+        if #available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *) {
+            return "\(path.path())/App"
+        } else {
+            return "\(path.path)/App"
+        }
+        #else
+        return "\(path.path)/App"
+        #endif
+    }
+
     /// Creates a directory at the specified path.
     ///
     /// - Parameters:

Tests/AppStateTests/FileStateTests.swift

@@ -11,7 +11,7 @@ fileprivate extension Application {
     }
 
     var storedString: FileState<String?> {
-        fileState(path: "./AppStateTests", filename: "storedstring")
+        fileState(filename: "storedstring")
     }
 }