Add Constant And Module Object

ProjectDescriptionHelpers/Constant.swift

@@ -0,0 +1,21 @@
+import ProjectDescription
+
+/// Constant value Property wrapper
+///
+/// Used for Constant Management.
+/// ```swift
+///  @Constant var env = Constants()
+/// ```
+@propertyWrapper public struct Constant<ObjectType> where ObjectType: ModuleObject {
+    private var value: ObjectType
+
+    public init(wrappedValue: ObjectType) {
+        self.value = wrappedValue
+    }
+
+    public var wrappedValue: ObjectType { value }
+
+    public var projectedValue: Constant<ObjectType> {
+        get { return self }
+    }
+}

ProjectDescriptionHelpers/Object/ModuleObject.swift

@@ -0,0 +1,13 @@
+import ProjectDescription
+
+/// ModuleObject Type
+/// Helps manage module variables that are used repeatedly by Tuist.
+///
+/// ```swift
+/// struct Constants: ModuleObject {
+///    static var version: String! = "x.y.z"
+///    static let config = AppConfig()
+///}
+/// ```
+///
+public protocol ModuleObject {}