3 files changed, 7 insertions, 88 deletions

diff --git a/runtime/js/01_web_util.js b/runtime/js/01_web_util.js
index 9b51021f9..ca3d74826 100644
--- a/runtime/js/01_web_util.js
+++ b/runtime/js/01_web_util.js
@@ -2,15 +2,7 @@
 "use strict";
 
 ((window) => {
-  const {
-    FunctionPrototypeCall,
-    Map,
-    MapPrototypeGet,
-    MapPrototypeSet,
-    ObjectDefineProperty,
-    TypeError,
-    Symbol,
-  } = window.__bootstrap.primordials;
+  const { TypeError, Symbol } = window.__bootstrap.primordials;
   const illegalConstructorKey = Symbol("illegalConstructorKey");
 
   function requiredArguments(
@@ -26,75 +18,8 @@
     }
   }
 
-  const handlerSymbol = Symbol("eventHandlers");
-  function makeWrappedHandler(handler, isSpecialErrorEventHandler) {
-    function wrappedHandler(...args) {
-      if (typeof wrappedHandler.handler !== "function") {
-        return;
-      }
-      if (isSpecialErrorEventHandler) {
-        const evt = args[0];
-        if (evt instanceof ErrorEvent && evt.type === "error") {
-          const ret = FunctionPrototypeCall(
-            wrappedHandler.handler,
-            this,
-            evt.message,
-            evt.filename,
-            evt.lineno,
-            evt.colno,
-            evt.error,
-          );
-          if (ret === true) {
-            evt.preventDefault();
-          }
-          return;
-        }
-      }
-
-      return FunctionPrototypeCall(wrappedHandler.handler, this, ...args);
-    }
-    wrappedHandler.handler = handler;
-    return wrappedHandler;
-  }
-  function defineEventHandler(
-    emitter,
-    name,
-    defaultValue = undefined,
-    isSpecialErrorEventHandler = false,
-  ) {
-    // HTML specification section 8.1.5.1
-    ObjectDefineProperty(emitter, `on${name}`, {
-      get() {
-        if (!this[handlerSymbol]) {
-          return defaultValue;
-        }
-
-        return MapPrototypeGet(this[handlerSymbol], name)?.handler ??
-          defaultValue;
-      },
-      set(value) {
-        if (!this[handlerSymbol]) {
-          this[handlerSymbol] = new Map();
-        }
-        let handlerWrapper = MapPrototypeGet(this[handlerSymbol], name);
-        if (handlerWrapper) {
-          handlerWrapper.handler = value;
-        } else {
-          handlerWrapper = makeWrappedHandler(
-            value,
-            isSpecialErrorEventHandler,
-          );
-          this.addEventListener(name, handlerWrapper);
-        }
-        MapPrototypeSet(this[handlerSymbol], name, handlerWrapper);
-      },
-      configurable: true,
-      enumerable: true,
-    });
-  }
   window.__bootstrap.webUtil = {
     illegalConstructorKey,
     requiredArguments,
-    defineEventHandler,
   };
 })(this);
diff --git a/runtime/js/11_workers.js b/runtime/js/11_workers.js
index 59ae7371d..53b256334 100644
--- a/runtime/js/11_workers.js
+++ b/runtime/js/11_workers.js
@@ -16,7 +16,7 @@
   const { URL } = window.__bootstrap.url;
   const { getLocationHref } = window.__bootstrap.location;
   const { log, pathFromURL } = window.__bootstrap.util;
-  const { defineEventHandler } = window.__bootstrap.webUtil;
+  const { defineEventHandler } = window.__bootstrap.event;
   const { deserializeJsMessageData, serializeJsMessageData } =
     window.__bootstrap.messagePort;
 
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index 4f21655d6..117200a28 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -59,7 +59,7 @@ delete Object.prototype.__proto__;
   const errors = window.__bootstrap.errors.errors;
   const webidl = window.__bootstrap.webidl;
   const domException = window.__bootstrap.domException;
-  const { defineEventHandler } = window.__bootstrap.webUtil;
+  const { defineEventHandler } = window.__bootstrap.event;
   const { deserializeJsMessageData, serializeJsMessageData } =
     window.__bootstrap.messagePort;
 
@@ -479,10 +479,6 @@ delete Object.prototype.__proto__;
       enumerable: true,
       get: () => navigator,
     },
-    // TODO(bartlomieju): from MDN docs (https://developer.mozilla.org/en-US/docs/Web/API/WorkerGlobalScope)
-    // it seems those two properties should be available to workers as well
-    onload: util.writable(null),
-    onunload: util.writable(null),
     close: util.writable(windowClose),
     closed: util.getterOnly(() => windowIsClosing),
     alert: util.writable(prompt.alert),
@@ -514,8 +510,6 @@ delete Object.prototype.__proto__;
       get: () => workerNavigator,
     },
     self: util.readOnly(globalThis),
-    onmessage: util.writable(null),
-    onerror: util.writable(null),
     // TODO(bartlomieju): should be readonly?
     close: util.nonEnumerable(workerClose),
     postMessage: util.writable(postMessage),
@@ -548,8 +542,8 @@ delete Object.prototype.__proto__;
 
     eventTarget.setEventTargetData(globalThis);
 
-    defineEventHandler(window, "load", null);
-    defineEventHandler(window, "unload", null);
+    defineEventHandler(window, "load");
+    defineEventHandler(window, "unload");
 
     const isUnloadDispatched = SymbolFor("isUnloadDispatched");
     // Stores the flag for checking whether unload is dispatched or not.
@@ -646,8 +640,8 @@ delete Object.prototype.__proto__;
 
     eventTarget.setEventTargetData(globalThis);
 
-    defineEventHandler(self, "message", null);
-    defineEventHandler(self, "error", null, true);
+    defineEventHandler(self, "message");
+    defineEventHandler(self, "error", undefined, true);
 
     runtimeStart(
       runtimeOptions,