diff --git a/html/browsers/the-window-object/self-et-al.window.js b/html/browsers/the-window-object/self-et-al.window.js
new file mode 100644
index 00000000000000..1b0fa1211a7012
--- /dev/null
+++ b/html/browsers/the-window-object/self-et-al.window.js
@@ -0,0 +1,43 @@
+function delayed_assert_done(t, w, windowProxySelfReference) {
+ // Let's make sure nobody is being sneaky
+ t.step_timeout(() => {
+ t.step_timeout(() => {
+ assert_equals(w[windowProxySelfReference], w, `${windowProxySelfReference} got cleared after some time`);
+ t.done();
+ }, 0);
+ }, 0);
+}
+
+[
+ "frames",
+ "globalThis",
+ "self",
+ "window"
+].forEach(windowProxySelfReference => {
+ async_test(t => {
+ const frame = document.body.appendChild(document.createElement("iframe")),
+ otherW = frame.contentWindow;
+ assert_equals(otherW[windowProxySelfReference], otherW, `${windowProxySelfReference} is broken`);
+ frame.remove();
+ assert_equals(otherW[windowProxySelfReference], otherW, `${windowProxySelfReference} got cleared after browsing context removal`);
+ assert_true(otherW.closed);
+
+ delayed_assert_done(t, otherW, windowProxySelfReference);
+ }, `iframeWindow.${windowProxySelfReference} before and after removal`);
+
+ async_test(t => {
+ const otherW = window.open();
+ assert_equals(otherW[windowProxySelfReference], otherW, `${windowProxySelfReference} is broken`);
+ otherW.onunload = t.step_func(() => {
+ assert_equals(otherW[windowProxySelfReference], otherW, `${windowProxySelfReference} got cleared after browsing context unload`);
+ t.step_timeout(() => {
+ assert_equals(otherW.opener, null); // Ensure browsing context is discarded
+ assert_equals(otherW[windowProxySelfReference], otherW, `${windowProxySelfReference} got cleared after browsing context removal`);
+ delayed_assert_done(t, otherW, windowProxySelfReference);
+ }, 0);
+ });
+ otherW.close();
+ assert_equals(otherW[windowProxySelfReference], otherW, `${windowProxySelfReference} got cleared after browsing context closure`);
+ assert_true(otherW.closed);
+ }, `popupWindow.${windowProxySelfReference} before, after closing, and after discarding`)
+});