1 files changed, 137 insertions, 0 deletions
diff --git a/dom/base/test/browser_aboutnewtab_process_selection.js b/dom/base/test/browser_aboutnewtab_process_selection.js
new file mode 100644
index 0000000000..ad59077105
--- /dev/null
+++ b/dom/base/test/browser_aboutnewtab_process_selection.js
@@ -0,0 +1,137 @@
+const TEST_URL = "http://www.example.com/browser/dom/base/test/dummy.html";
+const TEST_URL_2 = "http://example.org/browser/dom/base/test/dummy.html";
+const PRELOADED_STATE = "preloaded";
+
+var ppmm = Services.ppmm;
+
+add_task(async function () {
+  // We want to count processes in this test, so let's disable the pre-allocated process manager.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["dom.ipc.processPrelaunch.enabled", false],
+      ["dom.ipc.processCount", 10],
+      ["dom.ipc.processCount.webIsolated", 10],
+      ["dom.ipc.keepProcessesAlive.web", 10],
+    ],
+  });
+});
+
+add_task(async function () {
+  // This test is only relevant in e10s.
+  if (!gMultiProcessBrowser) {
+    return;
+  }
+
+  ppmm.releaseCachedProcesses();
+
+  // Wait for the preloaded browser to load.
+  await BrowserTestUtils.maybeCreatePreloadedBrowser(gBrowser);
+
+  // Store the number of processes.
+  let expectedChildCount = ppmm.childCount;
+
+  // Open 3 tabs using the preloaded browser.
+  let tabs = [];
+  for (let i = 0; i < 3; i++) {
+    BrowserOpenTab();
+    tabs.unshift(gBrowser.selectedTab);
+    await BrowserTestUtils.maybeCreatePreloadedBrowser(gBrowser);
+
+    // Check that the process count did not change.
+    is(
+      ppmm.childCount,
+      expectedChildCount,
+      "Preloaded browser should not create a new content process."
+    );
+  }
+
+  // Navigate to a content page from the parent side.
+  //
+  // We should create a new content process.
+  expectedChildCount += 1;
+  BrowserTestUtils.startLoadingURIString(tabs[0].linkedBrowser, TEST_URL);
+  await BrowserTestUtils.browserLoaded(tabs[0].linkedBrowser, false, TEST_URL);
+  is(
+    ppmm.childCount,
+    expectedChildCount,
+    "Navigating away from the preloaded browser (parent side) should create a new content process."
+  );
+
+  // Navigate to the same content page from the child side.
+  //
+  // We should create a new content process.
+  expectedChildCount += 1;
+  await BrowserTestUtils.switchTab(gBrowser, tabs[1]);
+  await SpecialPowers.spawn(tabs[1].linkedBrowser, [TEST_URL], url => {
+    content.location.href = url;
+  });
+  await BrowserTestUtils.browserLoaded(tabs[1].linkedBrowser, false, TEST_URL);
+  is(
+    ppmm.childCount,
+    expectedChildCount,
+    "Navigating away from the preloaded browser (child side, same-origin) should create a new content process."
+  );
+
+  // Navigate to a new content page from the child side.
+  //
+  // We should create a new content process.
+  expectedChildCount += 1;
+  await BrowserTestUtils.switchTab(gBrowser, tabs[2]);
+  await ContentTask.spawn(tabs[2].linkedBrowser, TEST_URL_2, url => {
+    content.location.href = url;
+  });
+  await BrowserTestUtils.browserLoaded(
+    tabs[2].linkedBrowser,
+    false,
+    TEST_URL_2
+  );
+  is(
+    ppmm.childCount,
+    expectedChildCount,
+    "Navigating away from the preloaded browser (child side, cross-origin) should create a new content process."
+  );
+
+  for (let tab of tabs) {
+    BrowserTestUtils.removeTab(tab);
+  }
+
+  // Make sure the preload browser does not keep any of the new processes alive.
+  NewTabPagePreloading.removePreloadedBrowser(window);
+
+  // Since we kept alive all the processes, we can shut down the ones that do
+  // not host any tabs reliably.
+  ppmm.releaseCachedProcesses();
+});
+
+add_task(async function preloaded_state_attribute() {
+  // Wait for a preloaded browser to exist, use it, and then create another one
+  await BrowserTestUtils.maybeCreatePreloadedBrowser(gBrowser);
+  let preloadedTabState =
+    gBrowser.preloadedBrowser.getAttribute("preloadedState");
+  is(
+    preloadedTabState,
+    PRELOADED_STATE,
+    "Sanity check that the first preloaded browser has the correct attribute"
+  );
+
+  BrowserOpenTab();
+  await BrowserTestUtils.maybeCreatePreloadedBrowser(gBrowser);
+
+  // Now check that the tabs have the correct browser attributes set
+  is(
+    gBrowser.selectedBrowser.hasAttribute("preloadedState"),
+    false,
+    "The opened tab consumed the preloaded browser and removed the attribute"
+  );
+
+  preloadedTabState = gBrowser.preloadedBrowser.getAttribute("preloadedState");
+  is(
+    preloadedTabState,
+    PRELOADED_STATE,
+    "The preloaded browser has the correct attribute"
+  );
+
+  // Remove tabs and preloaded browsers
+  BrowserTestUtils.removeTab(gBrowser.selectedTab);
+  NewTabPagePreloading.removePreloadedBrowser(window);
+});