add_task(async function testRestoreDefaultsBtn_visible() {
  const before = SpecialPowers.Services.prefs.getStringPref(
    "browser.newtabpage.activity-stream.feeds.section.topstories.options",
    ""
  );

  await SpecialPowers.pushPrefEnv({
    set: [
      // Hide Pocket prefs so we don't trigger network requests when we reset all preferences
      [
        "browser.newtabpage.activity-stream.feeds.section.topstories.options",
        JSON.stringify(Object.assign({}, JSON.parse(before), { hidden: true })),
      ],
      [
        "browser.newtabpage.activity-stream.discoverystream.endpointSpocsClear",
        "",
      ],
      // Set a user pref to false to force the Restore Defaults button to be visible
      ["browser.newtabpage.activity-stream.feeds.topsites", false],
    ],
  });

  let tab = await BrowserTestUtils.openNewForegroundTab(
    gBrowser,
    "about:preferences#home",
    false
  );
  let browser = tab.linkedBrowser;

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.getElementById("restoreDefaultHomePageBtn") !== null
      ),
    "Wait for the button to be added to the page"
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.querySelector(
            "[data-subcategory='topsites'] checkbox"
          ) !== null
      ),
    "Wait for the preference checkbox to load"
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.getElementById("restoreDefaultHomePageBtn")
            .hidden === false
      ),
    "Should show the Restore Defaults btn because pref is changed"
  );

  await SpecialPowers.spawn(browser, [], () =>
    content.document.getElementById("restoreDefaultHomePageBtn").click()
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.querySelector(
            "[data-subcategory='topsites'] checkbox"
          ).checked
      ),
    "Should have checked preference"
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.getElementById("restoreDefaultHomePageBtn").style
            .visibility === "hidden"
      ),
    "Should not show the Restore Defaults btn if prefs were reset"
  );

  const topsitesPref = await SpecialPowers.Services.prefs.getBoolPref(
    "browser.newtabpage.activity-stream.feeds.topsites"
  );
  Assert.ok(topsitesPref, "Topsites pref should have the default value");

  await SpecialPowers.popPrefEnv();
  BrowserTestUtils.removeTab(tab);
});

add_task(async function testRestoreDefaultsBtn_hidden() {
  const before = SpecialPowers.Services.prefs.getStringPref(
    "browser.newtabpage.activity-stream.feeds.section.topstories.options",
    ""
  );

  await SpecialPowers.pushPrefEnv({
    set: [
      // Hide Pocket pref so we don't trigger network requests when we reset all preferences
      [
        "browser.newtabpage.activity-stream.feeds.section.topstories.options",
        JSON.stringify(Object.assign({}, JSON.parse(before), { hidden: true })),
      ],
      [
        "browser.newtabpage.activity-stream.discoverystream.endpointSpocsClear",
        "",
      ],
    ],
  });

  let tab = await BrowserTestUtils.openNewForegroundTab(
    gBrowser,
    "about:preferences#home",
    false
  );
  let browser = tab.linkedBrowser;

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.getElementById("restoreDefaultHomePageBtn") !== null
      ),
    "Wait for the button to be added to the page"
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.querySelector(
            "[data-subcategory='topsites'] checkbox"
          ) !== null
      ),
    "Wait for the preference checkbox to load"
  );

  const btnDefault = await SpecialPowers.spawn(
    browser,
    [],
    () =>
      content.document.getElementById("restoreDefaultHomePageBtn").style
        .visibility
  );
  Assert.equal(
    btnDefault,
    "hidden",
    "When no prefs are changed button should not show up"
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.querySelector(
            "[data-subcategory='topsites'] checkbox"
          ).checked
      ),
    "Should have checked preference"
  );

  // Uncheck a pref
  await SpecialPowers.spawn(browser, [], () =>
    content.document
      .querySelector("[data-subcategory='topsites'] checkbox")
      .click()
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          !content.document.querySelector(
            "[data-subcategory='topsites'] checkbox"
          ).checked
      ),
    "Should have unchecked preference"
  );

  await BrowserTestUtils.waitForCondition(
    () =>
      SpecialPowers.spawn(
        browser,
        [],
        () =>
          content.document.getElementById("restoreDefaultHomePageBtn").style
            .visibility === ""
      ),
    "Should show the Restore Defaults btn if prefs were changed"
  );

  // Reset the pref
  await SpecialPowers.Services.prefs.clearUserPref(
    "browser.newtabpage.activity-stream.feeds.topsites"
  );

  await SpecialPowers.popPrefEnv();
  BrowserTestUtils.removeTab(tab);
});