fix(runtime): don't crash when window is deleted (#13392)

This commit fixes an error when user deletes "window" global JS
variable. Instead of relying on "window" or "globalThis" to dispatch
"load" and "unload" events, we are default to global scope of the
worker.

cli/tests/integration/run_tests.rs

@@ -2480,6 +2480,11 @@ itest!(import_assertions_type_check {
   exit_code: 1,
 });
 
+itest!(delete_window {
+  args: "run delete_window.js",
+  output_str: Some("true\n"),
+});
+
 itest!(colors_without_global_this {
   args: "run colors_without_globalThis.js",
   output_str: Some("true\n"),

cli/tests/testdata/delete_window.js

@@ -0,0 +1 @@
+console.log(delete globalThis.window);

ext/web/02_event.js

@@ -970,7 +970,11 @@
       webidl.requiredArguments(arguments.length, 1, {
         prefix: "Failed to execute 'dispatchEvent' on 'EventTarget'",
       });
-      const self = this ?? globalThis;
+      // If `this` is not present, then fallback to global scope. We don't use
+      // `globalThis` directly here, because it could be deleted by user.
+      // Instead use saved reference to global scope when the script was
+      // executed.
+      const self = this ?? window;
 
       const { listeners } = self[eventTargetData];
       if (!(event.type in listeners)) {

runtime/worker.rs

@@ -313,7 +313,13 @@ impl MainWorker {
     &mut self,
     script_name: &str,
   ) -> Result<(), AnyError> {
-    self.execute_script(script_name, "window.dispatchEvent(new Event('load'))")
+    self.execute_script(
+      script_name,
+      // NOTE(@bartlomieju): not using `globalThis` here, because user might delete
+      // it. Instead we're using global `dispatchEvent` function which will
+      // used a saved reference to global scope.
+      "dispatchEvent(new Event('load'))",
+    )
   }
 
   /// Dispatches "unload" event to the JavaScript runtime.
@@ -323,8 +329,13 @@ impl MainWorker {
     &mut self,
     script_name: &str,
   ) -> Result<(), AnyError> {
-    self
-      .execute_script(script_name, "window.dispatchEvent(new Event('unload'))")
+    self.execute_script(
+      script_name,
+      // NOTE(@bartlomieju): not using `globalThis` here, because user might delete
+      // it. Instead we're using global `dispatchEvent` function which will
+      // used a saved reference to global scope.
+      "dispatchEvent(new Event('unload'))",
+    )
   }
 }