Bug 1565507 - Enable default theme on theme uninstallation r=aswan

... and re-enable the original theme when the uninstallation is undone,
iff it was enabled before.

Differential Revision: https://phabricator.services.mozilla.com/D39381

--HG--
extra : moz-landing-system : lando

toolkit/mozapps/extensions/internal/XPIDatabase.jsm

@@ -1874,7 +1874,7 @@ this.XPIDatabase = {
       if (theme.visible) {
         if (!aId && theme.id == DEFAULT_THEME_ID) {
           enableTheme = theme;
-        } else if (theme.id != aId) {
+        } else if (theme.id != aId && !theme.pendingUninstall) {
           this.updateAddonDisabledState(theme, true, undefined, true);
         }
       }

toolkit/mozapps/extensions/internal/XPIInstall.jsm

@@ -4422,6 +4422,7 @@ var XPIInstall = {
       aAddon._updateCheck.cancel();
     }
 
+    let wasActive = aAddon.active;
     let wasPending = aAddon.pendingUninstall;
 
     if (aForcePending) {
@@ -4524,7 +4525,8 @@ var XPIInstall = {
     }
 
     // Notify any other providers that a new theme has been enabled
-    if (aAddon.type === "theme" && aAddon.active) {
+    // (when the active theme is uninstalled, the default theme is enabled).
+    if (aAddon.type === "theme" && wasActive) {
       AddonManagerPrivate.notifyAddonChanged(null, aAddon.type);
     }
   },

toolkit/mozapps/extensions/test/browser/browser_html_list_view.js

@@ -597,13 +597,17 @@ add_task(async function testThemeList() {
     "There is one enabled theme"
   );
 
-  let themesChanged = waitForThemeChange(list);
-  card.querySelector('[action="toggle-disabled"]').click();
-  await themesChanged;
+  let toggleThemeEnabled = async () => {
+    let themesChanged = waitForThemeChange(list);
+    card.querySelector('[action="toggle-disabled"]').click();
+    await themesChanged;
 
-  await TestUtils.waitForCondition(
-    () => enabledSection.querySelectorAll("addon-card").length == 1
-  );
+    await TestUtils.waitForCondition(
+      () => enabledSection.querySelectorAll("addon-card").length == 1
+    );
+  };
+
+  await toggleThemeEnabled();
 
   is(
     card.parentNode,
@@ -616,6 +620,31 @@ add_task(async function testThemeList() {
     "There is one enabled theme"
   );
 
+  // Re-enable the theme.
+  await toggleThemeEnabled();
+  is(card.parentNode, enabledSection, "Card is back in the Enabled section");
+
+  // Remove theme and verify that the default theme is re-enabled.
+  let removed = BrowserTestUtils.waitForEvent(list, "remove");
+  // Confirm removal.
+  promptService._response = 0;
+  card.querySelector('[action="remove"]').click();
+  await removed;
+  is(card.parentNode, null, "Card has been removed from the view");
+  await TestUtils.waitForCondition(
+    () => enabledSection.querySelectorAll("addon-card").length == 1
+  );
+
+  let defaultTheme = getCardByAddonId(doc, "default-theme@mozilla.org");
+  is(defaultTheme.parentNode, enabledSection, "The default theme is reenabled");
+
+  await testUndoPendingUninstall(list, card.addon);
+  await TestUtils.waitForCondition(
+    () => enabledSection.querySelectorAll("addon-card").length == 1
+  );
+  is(defaultTheme.parentNode, disabledSection, "The default theme is disabled");
+  ok(getCardByAddonId(enabledSection, theme.id), "Theme should be reenabled");
+
   await theme.unload();
   await closeView(win);
 });

toolkit/mozapps/extensions/test/xpcshell/test_webextension_theme.js

@@ -50,9 +50,7 @@ add_task(async function setup_to_default_browserish_state() {
 
   if (AppConstants.MOZ_DEV_EDITION) {
     // Developer Edition selects the wrong theme by default.
-    let defaultTheme = await AddonManager.getAddonByID(
-      "default-theme@mozilla.org"
-    );
+    let defaultTheme = await AddonManager.getAddonByID(DEFAULT_THEME);
     await defaultTheme.enable();
   }
 
@@ -178,48 +176,84 @@ add_task(async function test_default_theme() {
 });
 
 add_task(async function uninstall_offers_undo() {
+  let defaultTheme = await AddonManager.getAddonByID(DEFAULT_THEME);
   const ID = THEME_IDS[0];
   let theme = await promiseAddonByID(ID);
 
   Assert.ok(theme, "Webextension theme is present");
-  Assert.ok(!theme.isActive, "Webextension theme is not active");
 
-  function promiseAddonEvent(event, id) {
-    return new Promise(resolve => {
-      let listener = {
-        // eslint-disable-next-line object-shorthand
-        [event]: function(addon) {
-          if (id) {
-            Assert.equal(addon.id, id, "Got event for expected addon");
-          }
-          AddonManager.removeAddonListener(listener);
-          resolve();
-        },
-      };
-      AddonManager.addAddonListener(listener);
-    });
+  async function promiseAddonEvent(event, id) {
+    let [addon] = await AddonTestUtils.promiseAddonEvent(event);
+    if (id) {
+      Assert.equal(addon.id, id, `Got event for expected addon (${event})`);
+    }
   }
 
-  let uninstallingPromise = promiseAddonEvent("onUninstalling", ID);
-  await theme.uninstall(true);
-  await uninstallingPromise;
+  async function uninstallTheme() {
+    let uninstallingPromise = promiseAddonEvent("onUninstalling", ID);
+    await theme.uninstall(true);
+    await uninstallingPromise;
 
-  Assert.ok(
-    hasFlag(theme.pendingOperations, AddonManager.PENDING_UNINSTALL),
-    "Theme being uninstalled has PENDING_UNINSTALL flag"
-  );
+    Assert.ok(
+      hasFlag(theme.pendingOperations, AddonManager.PENDING_UNINSTALL),
+      "Theme being uninstalled has PENDING_UNINSTALL flag"
+    );
+  }
 
-  let cancelPromise = promiseAddonEvent("onOperationCancelled", ID);
-  theme.cancelUninstall();
-  await cancelPromise;
+  async function cancelUninstallTheme() {
+    let cancelPromise = promiseAddonEvent("onOperationCancelled", ID);
+    theme.cancelUninstall();
+    await cancelPromise;
 
-  Assert.equal(
-    theme.pendingOperations,
-    AddonManager.PENDING_NONE,
-    "PENDING_UNINSTALL flag is cleared when uninstall is canceled"
-  );
+    Assert.equal(
+      theme.pendingOperations,
+      AddonManager.PENDING_NONE,
+      "PENDING_UNINSTALL flag is cleared when uninstall is canceled"
+    );
+  }
+
+  // A theme should still be disabled if the uninstallation of a disabled theme
+  // is undone.
+  Assert.ok(!theme.isActive, "Webextension theme is not active");
+  Assert.ok(defaultTheme.isActive, "Default theme is active");
+  await uninstallTheme();
+  await cancelUninstallTheme();
+  Assert.ok(!theme.isActive, "Webextension theme is still not active");
+  Assert.ok(defaultTheme.isActive, "Default theme is still active");
+
+  // Enable theme, the previously active theme should be disabled.
+  await Promise.all([
+    promiseAddonEvent("onDisabled", DEFAULT_THEME),
+    promiseAddonEvent("onEnabled", ID),
+    theme.enable(),
+  ]);
+  Assert.ok(theme.isActive, "Webextension theme is active after enabling");
+  Assert.ok(!defaultTheme.isActive, "Default theme is not active any more");
+
+  // Uninstall active theme, default theme should become active.
+  await Promise.all([
+    // Note: no listener for onDisabled & ID because the uninstall is pending.
+    promiseAddonEvent("onEnabled", DEFAULT_THEME),
+    uninstallTheme(),
+  ]);
+  Assert.ok(!theme.isActive, "Webextension theme is not active upon uninstall");
+  Assert.ok(defaultTheme.isActive, "Default theme is active again");
+
+  // Undo uninstall, default theme should be deactivated.
+  await Promise.all([
+    // Note: no listener for onEnabled & ID because the uninstall was pending.
+    promiseAddonEvent("onDisabled", DEFAULT_THEME),
+    cancelUninstallTheme(),
+  ]);
+  Assert.ok(theme.isActive, "Webextension theme is active upon undo uninstall");
+  Assert.ok(!defaultTheme.isActive, "Default theme is not active again");
+
+  // Immediately remove the theme. Default theme should be activated.
+  await Promise.all([
+    promiseAddonEvent("onEnabled", DEFAULT_THEME),
+    theme.uninstall(),
+  ]);
 
-  await theme.uninstall();
   await promiseRestartManager();
 });