/// Use this protocol when your type has no single JavaScript class. /// For example, a union type of multiple classes or primitive values. public protocol JSBridgedType: JSValueCompatible, CustomStringConvertible { /// If your class is incompatible with the provided value, return `nil`. init?(from value: JSValue) } public extension JSBridgedType { static func construct(from value: JSValue) -> Self? { Self(from: value) } var description: String { jsValue.description } } /// Conform to this protocol when your Swift class wraps a JavaScript class. public protocol JSBridgedClass: JSBridgedType { /// The constructor function for the JavaScript class static var constructor: JSFunction? { get } /// The JavaScript object wrapped by this instance. /// You may assume that `jsObject instanceof Self.constructor == true` var jsObject: JSObject { get } /// Create an instance wrapping the given JavaScript object. /// You may assume that `jsObject instanceof Self.constructor` init(unsafelyWrapping jsObject: JSObject) } public extension JSBridgedClass { var jsValue: JSValue { jsObject.jsValue } init?(from value: JSValue) { guard let object = value.object else { return nil } self.init(from: object) } init?(from object: JSObject) { guard let constructor = Self.constructor, object.isInstanceOf(constructor) else { return nil } self.init(unsafelyWrapping: object) } }