1 files changed, 55 insertions, 0 deletions
diff --git a/browser/components/originattributes/test/browser/browser_firstPartyIsolation_about_newtab.js b/browser/components/originattributes/test/browser/browser_firstPartyIsolation_about_newtab.js
new file mode 100644
index 0000000000..b3e175c6a1
--- /dev/null
+++ b/browser/components/originattributes/test/browser/browser_firstPartyIsolation_about_newtab.js
@@ -0,0 +1,55 @@
+add_setup(async function () {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.newtab.preload", false],
+      ["privacy.firstparty.isolate", true],
+    ],
+  });
+});
+
+/**
+ * Test about:newtab will have firstPartytDomain set when we enable the pref.
+ *
+ * We split about:newtab from browser_firstPartyIsolation_aboutPages.js because
+ * about:newtab needs special care.
+ *
+ * In the original test browser_firstPartyIsolation_aboutPages.js, when calling
+ * tabbrowser.addTab, if it found out the uri is about:newtab, it will use
+ * the preloaded browser, however the preloaded browser is loaded before when we
+ * turn on the firstPartyIsolation pref, which won't have the pref set.
+ *
+ * To prevent to use the preloaded browser, a simple trick is open a window
+ * first.
+ **/
+add_task(async function test_aboutNewTab() {
+  // In Fission, we cannot open a non-remote window.
+  let win = await BrowserTestUtils.openNewBrowserWindow({
+    remote: SpecialPowers.useRemoteSubframes,
+  });
+  let gbrowser = win.gBrowser;
+  let tab = BrowserTestUtils.addTab(gbrowser, "about:newtab");
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  let attrs = {
+    firstPartyDomain: "about.ef2a7dd5-93bc-417f-a698-142c3116864f.mozilla",
+  };
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [{ attrs }],
+    async function (args) {
+      Assert.ok(true, "principal " + content.document.nodePrincipal.origin);
+      Assert.equal(
+        content.document.nodePrincipal.originAttributes.firstPartyDomain,
+        args.attrs.firstPartyDomain,
+        "about:newtab should have firstPartyDomain set"
+      );
+      Assert.ok(
+        content.document.nodePrincipal.isContentPrincipal,
+        "The principal should be a content principal."
+      );
+    }
+  );
+
+  gbrowser.removeTab(tab);
+  win.close();
+});