Add DebugDescription (#37)

Author: muukii

Sources/StateStruct/PropertyPath.swift

@@ -1,5 +1,6 @@
 
-public struct PropertyPath: Equatable {
+@DebugDescription
+public struct PropertyPath: Equatable, CustomDebugStringConvertible {
 
   public struct Component: Equatable {
 
@@ -11,7 +12,13 @@ public struct PropertyPath: Equatable {
 
   }
 
-  public var components: [Component] = []
+  public var components: [Component] = [] {
+    didSet {
+      #if DEBUG
+      _joined = components.map { $0.value }.joined(separator: ".")
+      #endif
+    }
+  }
 
   public init() {
 
@@ -26,5 +33,19 @@ public struct PropertyPath: Equatable {
     self.components.append(component)
     return self
   }
+  
+  #if DEBUG
+  private var _joined: String = ""
+  #endif
+  
+  #if DEBUG
+  public var debugDescription: String {
+    "\(_joined) \(components.count)"
+  }
+  #else
+  public var debugDescription: String {
+    "Components : \(components.count)"
+  }
+  #endif
 
 }

Sources/StateStruct/TrackingRuntime.swift

@@ -11,8 +11,13 @@ public enum TrackingRuntime {
     trackingContext: borrowing _TrackingContext
   ) -> Value {
 
-    trackingContext.trackingResultRef?.accessorRead(path: trackingContext.path?.pushed(component))
-
+    if 
+      let ref = trackingContext.trackingResultRef,
+      let path = trackingContext.path
+    {
+      ref.accessorRead(path: path.pushed(component))
+    }
+      
     if var value = value as? TrackingObject, let ref = trackingContext.trackingResultRef {
 
       if value._tracking_context.trackingResultRef !== ref {