Support window.onload (#2643)

1 files changed, 23 insertions, 0 deletions

diff --git a/js/globals.ts b/js/globals.ts
index 1d33f6523..3be55e979 100644
--- a/js/globals.ts
+++ b/js/globals.ts
@@ -69,6 +69,7 @@ window.console = console;
 window.setTimeout = timers.setTimeout;
 window.setInterval = timers.setInterval;
 window.location = (undefined as unknown) as domTypes.Location;
+window.onload = undefined as undefined | Function;
 // The following Crypto interface implementation is not up to par with the
 // standard https://www.w3.org/TR/WebCryptoAPI/#crypto-interface as it does not
 // yet incorporate the SubtleCrypto interface as its "subtle" property.
@@ -135,6 +136,28 @@ window.postMessage = workers.postMessage;
 window.Worker = workers.WorkerImpl;
 export type Worker = workers.Worker;
 
+window[domTypes.eventTargetHost] = null;
+window[domTypes.eventTargetListeners] = {};
+window[domTypes.eventTargetMode] = "";
+window[domTypes.eventTargetNodeType] = 0;
+window[eventTarget.eventTargetAssignedSlot] = false;
+window[eventTarget.eventTargetHasActivationBehavior] = false;
+window.addEventListener = eventTarget.EventTarget.prototype.addEventListener;
+window.dispatchEvent = eventTarget.EventTarget.prototype.dispatchEvent;
+window.removeEventListener =
+  eventTarget.EventTarget.prototype.removeEventListener;
+
+// Registers the handler for window.onload function.
+window.addEventListener(
+  "load",
+  (e: domTypes.Event): void => {
+    const onload = window.onload;
+    if (typeof onload === "function") {
+      onload(e);
+    }
+  }
+);
+
 // below are interfaces that are available in TypeScript but
 // have different signatures
 export interface ImportMeta {