1 files changed, 40 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/observable/tentative/observable-map.window.js b/testing/web-platform/tests/dom/observable/tentative/observable-map.window.js
new file mode 100644
index 0000000000..06bf2e26b5
--- /dev/null
+++ b/testing/web-platform/tests/dom/observable/tentative/observable-map.window.js
@@ -0,0 +1,40 @@
+async function loadIframeAndReturnContentWindow() {
+   // Create and attach an iframe.
+  const iframe = document.createElement('iframe');
+  const iframeLoadPromise = new Promise((resolve, reject) => {
+    iframe.onload = resolve;
+    iframe.onerror = reject;
+  });
+  document.body.append(iframe);
+  await iframeLoadPromise;
+  return iframe.contentWindow;
+}
+
+promise_test(async t => {
+  const contentWin = await loadIframeAndReturnContentWindow();
+
+  window.results = [];
+
+  contentWin.eval(`
+    const parentResults = parent.results;
+
+    const source = new Observable(subscriber => {
+      // Detach the document before calling next().
+      window.frameElement.remove();
+
+      // This invokes the map() operator's internal observer's next steps,
+      // which at least in Chromium, must have a special "context is detached"
+      // check to early-return, so as to not crash before invoking the "mapper"
+      // callback supplied to the map() operator.
+      subscriber.next(1);
+    });
+
+    source.map(value => {
+      parentResults.push(value);
+    }).subscribe(v => parentResults.push(v));
+  `);
+
+  // If we got here, we didn't crash! Let's also check that `results` is empty.
+  assert_array_equals(results, []);
+}, "map()'s internal observer's next steps do not crash in a detached document");
+