1 files changed, 68 insertions, 0 deletions
diff --git a/dom/tests/browser/browser_data_document_crossOriginIsolated.js b/dom/tests/browser/browser_data_document_crossOriginIsolated.js
new file mode 100644
index 0000000000..d38eda3f0a
--- /dev/null
+++ b/dom/tests/browser/browser_data_document_crossOriginIsolated.js
@@ -0,0 +1,68 @@
+"use strict";
+
+const DIRPATH = getRootDirectory(gTestPath).replace(
+  "chrome://mochitests/content/",
+  ""
+);
+const PATH = DIRPATH + "file_coop_coep.html";
+
+const ORIGIN = "https://test1.example.com";
+const URL = `${ORIGIN}/${PATH}`;
+
+add_task(async function () {
+  await BrowserTestUtils.withNewTab(URL, async function (browser) {
+    BrowserTestUtils.loadURIString(browser, URL);
+    await BrowserTestUtils.browserLoaded(browser);
+
+    await SpecialPowers.spawn(browser, [ORIGIN], async origin => {
+      is(
+        content.window.origin,
+        origin,
+        `Opened a tab and navigated to ${origin}`
+      );
+
+      ok(
+        content.window.crossOriginIsolated,
+        `Should have been cross-origin-isolated env`
+      );
+
+      let hostIds = [];
+      function createShadowDOMAndTriggerSlotChange(host) {
+        var shadow = host.attachShadow({ mode: "closed" });
+
+        let promise = new Promise(resolve => {
+          shadow.addEventListener("slotchange", function () {
+            hostIds.push(host.id);
+            resolve();
+          });
+        });
+
+        shadow.innerHTML = "<slot></slot>";
+
+        host.appendChild(host.ownerDocument.createElement("span"));
+
+        return promise;
+      }
+
+      let host1 = content.document.getElementById("host1");
+
+      let dataDoc = content.document.implementation.createHTMLDocument();
+      dataDoc.body.innerHTML = "<div id='host2'></div>";
+      let host2 = dataDoc.body.firstChild;
+
+      let host3 = content.document.getElementById("host3");
+
+      let promises = [];
+      promises.push(createShadowDOMAndTriggerSlotChange(host1));
+      promises.push(createShadowDOMAndTriggerSlotChange(host2));
+      promises.push(createShadowDOMAndTriggerSlotChange(host3));
+
+      await Promise.all(promises);
+
+      is(hostIds.length, 3, `Got 3 slot change events`);
+      is(hostIds[0], "host1", `The first one was host1`);
+      is(hostIds[1], "host2", `The second one was host2`);
+      is(hostIds[2], "host3", `The third one was host3`);
+    });
+  });
+});