Foreign tab suggestions should update when disabling sync or signing out.

components/ntp_snippets/sessions/tab_delegate_sync_adapter_unittest.cc

Index: components/ntp_snippets/sessions/tab_delegate_sync_adapter_unittest.cc
diff --git a/components/ntp_snippets/sessions/tab_delegate_sync_adapter_unittest.cc b/components/ntp_snippets/sessions/tab_delegate_sync_adapter_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b10c7d56f093f308f89710855367f5c2d4df8d4b
--- /dev/null
+++ b/components/ntp_snippets/sessions/tab_delegate_sync_adapter_unittest.cc
@@ -0,0 +1,152 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/ntp_snippets/sessions/tab_delegate_sync_adapter.h"
+
+#include <string>
+
+#include "base/macros.h"
+#include "components/sync/driver/fake_sync_service.h"
+#include "components/sync_sessions/open_tabs_ui_delegate.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using base::RefCountedMemory;
+using sessions::SessionTab;
+using sessions::SessionWindow;
+using syncer::SyncServiceObserver;
+using sync_sessions::SyncedSession;
+using sync_sessions::OpenTabsUIDelegate;
+using testing::Test;
+
+namespace ntp_snippets {
+namespace {
+
+class TestSyncService : public syncer::FakeSyncService {
+ public:
+  TestSyncService() {}
+  OpenTabsUIDelegate* GetOpenTabsUIDelegate() override { return tabs_; }
+  OpenTabsUIDelegate* tabs_ = nullptr;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestSyncService);
+};
+
+class MockOpenTabsUIDelegate : public OpenTabsUIDelegate {
+ public:
+  MockOpenTabsUIDelegate() {}
+  MOCK_CONST_METHOD2(GetSyncedFaviconForPageURL,
+                     bool(const std::string&,
+                          scoped_refptr<RefCountedMemory>*));
+  MOCK_METHOD1(GetAllForeignSessions, bool(std::vector<const SyncedSession*>*));
+  MOCK_METHOD3(GetForeignTab,
+               bool(const std::string&,
+                    SessionID::id_type,
+                    const SessionTab**));
+  MOCK_METHOD1(DeleteForeignSession, void(const std::string&));
+  MOCK_METHOD2(GetForeignSession,
+               bool(const std::string&, std::vector<const SessionWindow*>*));
+  MOCK_METHOD2(GetForeignSessionTabs,
+               bool(const std::string&, std::vector<const SessionTab*>*));
+  MOCK_METHOD1(GetLocalSession, bool(const SyncedSession**));
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MockOpenTabsUIDelegate);
+};
+
+class TabDelegateSyncAdapterTest : public Test {
+ public:
+  TabDelegateSyncAdapterTest() : adapter_(&service_) {
+    adapter_.SubscribeForForeignTabChange(base::Bind(
+        &TabDelegateSyncAdapterTest::OnChange, base::Unretained(this)));
+  }
+
+  SyncServiceObserver* observer() { return &adapter_; }
+
+  void SetHasOpenTabs(bool is_enabled) {
+    service_.tabs_ = is_enabled ? &tabs_ : nullptr;
+  }
+
+  void OnChange() { ++callback_count_; }
+
+  int CallbackCount() { return callback_count_; }
+
+ private:
+  MockOpenTabsUIDelegate tabs_;
+  TestSyncService service_;
+  TabDelegateSyncAdapter adapter_;
+  int callback_count_ = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(TabDelegateSyncAdapterTest);
+};
+
+// CallbackCount should only trigger on transitions between having and not
+// having open tabs.
+TEST_F(TabDelegateSyncAdapterTest, CallbackCount) {
+  ASSERT_EQ(0, CallbackCount());
+  observer()->OnStateChanged();
+  EXPECT_EQ(0, CallbackCount());
+
+  SetHasOpenTabs(true);
+  observer()->OnStateChanged();
+  EXPECT_EQ(1, CallbackCount());
+  observer()->OnStateChanged();
+  EXPECT_EQ(1, CallbackCount());
+
+  SetHasOpenTabs(false);
+  observer()->OnStateChanged();
+  EXPECT_EQ(2, CallbackCount());
+  observer()->OnStateChanged();
+  EXPECT_EQ(2, CallbackCount());
+
+  // OnSyncCycleCompleted should behave like OnStateChanged.
+  observer()->OnSyncCycleCompleted();
+  EXPECT_EQ(2, CallbackCount());
+  SetHasOpenTabs(true);
+  observer()->OnSyncCycleCompleted();
+  EXPECT_EQ(3, CallbackCount());
+  observer()->OnSyncCycleCompleted();
+  EXPECT_EQ(3, CallbackCount());
+}
+
+// No callback should be invoked from OnSyncConfigurationCompleted.
+TEST_F(TabDelegateSyncAdapterTest, OnSyncConfigurationCompleted) {
+  ASSERT_EQ(0, CallbackCount());
+
+  observer()->OnSyncConfigurationCompleted();
+  EXPECT_EQ(0, CallbackCount());
+
+  SetHasOpenTabs(true);
+  observer()->OnSyncConfigurationCompleted();
+  EXPECT_EQ(0, CallbackCount());
+}
+
+// OnForeignSessionUpdated should always trigger a callback.
+TEST_F(TabDelegateSyncAdapterTest, OnForeignSessionUpdated) {
+  ASSERT_EQ(0, CallbackCount());
+  observer()->OnForeignSessionUpdated();
+  EXPECT_EQ(1, CallbackCount());
+  observer()->OnForeignSessionUpdated();
+  EXPECT_EQ(2, CallbackCount());
+
+  SetHasOpenTabs(true);
+  observer()->OnForeignSessionUpdated();
+  EXPECT_EQ(3, CallbackCount());
+  observer()->OnForeignSessionUpdated();
+  EXPECT_EQ(4, CallbackCount());
+}
+
+// If OnForeignSessionUpdated is called before OnStateChanged, then calling
+// OnStateChanged should not trigger a callback.
+TEST_F(TabDelegateSyncAdapterTest, OnForeignSessionUpdatedUpdatesState) {
+  SetHasOpenTabs(true);
+  observer()->OnForeignSessionUpdated();
+  EXPECT_EQ(1, CallbackCount());
+
+  observer()->OnStateChanged();
+  EXPECT_EQ(1, CallbackCount());
+}
+
+}  // namespace
+}  // namespace ntp_snippets