1 files changed, 59 insertions, 0 deletions
diff --git a/dom/tests/browser/browser_autofocus_background.js b/dom/tests/browser/browser_autofocus_background.js
new file mode 100644
index 0000000000..ecac9a9a98
--- /dev/null
+++ b/dom/tests/browser/browser_autofocus_background.js
@@ -0,0 +1,59 @@
+add_task(async function () {
+  const URL =
+    "data:text/html,<!DOCTYPE html><html><body><input autofocus id='target'></body></html>";
+  const foregroundTab = gBrowser.selectedTab;
+  const backgroundTab = BrowserTestUtils.addTab(gBrowser);
+
+  // Ensure tab is still in the foreground.
+  is(
+    gBrowser.selectedTab,
+    foregroundTab,
+    "foregroundTab should still be selected"
+  );
+
+  // Load the second tab in the background.
+  const loadedPromise = BrowserTestUtils.browserLoaded(
+    backgroundTab.linkedBrowser,
+    /* includesubframes */ false,
+    URL
+  );
+  BrowserTestUtils.loadURIString(backgroundTab.linkedBrowser, URL);
+  await loadedPromise;
+
+  // Get active element in the tab.
+  let tagName = await SpecialPowers.spawn(
+    backgroundTab.linkedBrowser,
+    [],
+    async function () {
+      // Spec asks us to flush autofocus candidates in the
+      // `update-the-rendering` step, so we need to wait
+      // for a rAF to ensure autofocus candidates are
+      // flushed.
+      await new Promise(r => {
+        content.requestAnimationFrame(r);
+      });
+      return content.document.activeElement.tagName;
+    }
+  );
+
+  is(
+    tagName,
+    "INPUT",
+    "The background tab's focused element should be the <input>"
+  );
+
+  is(
+    gBrowser.selectedTab,
+    foregroundTab,
+    "foregroundTab tab should still be selected, shouldn't cause a tab switch"
+  );
+
+  is(
+    document.activeElement,
+    foregroundTab.linkedBrowser,
+    "The background tab's focused element should not cause the tab to be selected"
+  );
+
+  // Cleaning up.
+  BrowserTestUtils.removeTab(backgroundTab);
+});