content script messaging for safari app

src/safari/app/desktop/safari/SafariExtensionHandler.swift

@@ -15,6 +15,8 @@ class SafariExtensionHandler: SFSafariExtensionHandler {
         page.getPropertiesWithCompletionHandler { properties in
             NSLog("The extension received a message (\(messageName)) from a script injected into (\(String(describing: properties?.url))) with userInfo (\(userInfo ?? [:]))")
         }
+        
+        page.dispatchMessageToScript(withName: "getInfo", userInfo: ["hello": "world", "foo": "bar"])
     }
     
     override func toolbarItemClicked(in window: SFSafariWindow) {

src/safari/app/desktop/safari/script.js

@@ -1,3 +1,8 @@
-document.addEventListener("DOMContentLoaded", function(event) {
+document.addEventListener("DOMContentLoaded", (event) => {
-    safari.extension.dispatchMessage("Hello World!");
+                          safari.extension.dispatchMessage("Hello World!", { key: "value2" });
+                          
+                          safari.self.addEventListener("message", (e) => {
+                                                       console.log(e);
+                                                       
+                                                       });
 });