fune/browser/components/sessionstore/test/browser_906076_lazy_tabs.js

/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

const TEST_STATE = {
  windows: [{
    tabs: [
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
      { entries: [{ url: "http://example.com", triggeringPrincipal_base64 }] },
    ]
  }]
};

const TEST_STATE_2 = {
  windows: [{
    tabs: [
      { entries: [{ url: "about:robots", triggeringPrincipal_base64 }]
      },
      { entries: [],
        userTypedValue: "http://example.com",
        userTypedClear: 1
      }
    ]
  }]
};

function countNonLazyTabs(win) {
  win = win || window;
  let count = 0;
  for (let browser of win.gBrowser.browsers) {
    if (browser.isConnected) {
      count++;
    }
  }
  return count;
}

/**
 * Test that lazy browsers do not get prematurely inserted by
 * code accessing browser bound properties on the unbound browser.
 */

add_task(async function test() {
  await SpecialPowers.pushPrefEnv({
    "set": [
      ["browser.sessionstore.restore_on_demand", true],
      ["browser.sessionstore.restore_tabs_lazily", true],
    ]
  });

  let backupState = SessionStore.getBrowserState();

  await promiseBrowserState(TEST_STATE);

  info("Check that no lazy browsers get unnecessarily inserted after session restore");
  is(countNonLazyTabs(), 1, "Window has only 1 non-lazy tab");

  await TestUtils.topicObserved("sessionstore-state-write-complete");

  // When sessionstore write occurs, tabs are checked for state changes.
  // Make sure none of them insert their browsers when this happens.
  info("Check that no lazy browsers get inserted after sessionstore write");
  is(countNonLazyTabs(), 1, "Window has only 1 non-lazy tab");

  info("Check that lazy browser gets inserted properly");
  ok(!gBrowser.browsers[1].isConnected, "The browser that we're attempting to insert is indeed lazy");
  gBrowser._insertBrowser(gBrowser.tabs[1]);
  is(countNonLazyTabs(), 2, "Window now has 2 non-lazy tabs");

  // Check if any lazy tabs got inserted when window closes.
  let newWindow = await promiseNewWindowLoaded();

  SessionStore.setWindowState(newWindow, JSON.stringify(TEST_STATE));

  await new Promise(resolve => {
    newWindow.addEventListener("unload", () => {
      info("Check that no lazy browsers get inserted when window closes");
      is(countNonLazyTabs(newWindow), 1, "Window has only 1 non-lazy tab");

      info("Check that it is not possible to insert a lazy browser after the window closed");
      ok(!newWindow.gBrowser.browsers[1].isConnected, "The browser that we're attempting to insert is indeed lazy");
      newWindow.gBrowser._insertBrowser(newWindow.gBrowser.tabs[1]);
      is(countNonLazyTabs(newWindow), 1, "Window still has only 1 non-lazy tab");

      resolve();
    }, { once: true });

    newWindow.close();
  });

  // Bug 1365933.
  info("Check that session with tab having empty entries array gets restored properly");
  await promiseBrowserState(TEST_STATE_2);

  is(gBrowser.tabs.length, 2, "Window has 2 tabs");
  is(gBrowser.selectedBrowser.currentURI.spec, "about:robots", "Tab has the expected URL");

  gBrowser.selectedTab = gBrowser.tabs[1];
  await BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
  is(gBrowser.selectedBrowser.currentURI.spec, "http://example.com/", "Tab has the expected URL");

  // Cleanup.
  await promiseBrowserState(backupState);
});