[ios] TabIdTabHelper

ios/chrome/browser/web/tab_id_tab_helper_unittest.mm

+// Copyright 2017 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.
+
+#import "ios/chrome/browser/web/tab_id_tab_helper.h"
+
+#import "ios/web/public/test/fakes/test_web_state.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#import "testing/gtest_mac.h"
+#include "testing/platform_test.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// Test fixture for TabIDTabHelper class.
+class TabIDTabHelperTest : public PlatformTest {
+ protected:
+  web::TestWebState first_web_state_;
+  web::TestWebState second_web_state_;
+};
+
+// Tests that a TabID is returned for a WebState, and TabID's are different
+// for different WebStates.
+TEST_F(TabIDTabHelperTest, TabIDForWebState) {
+  TabIDTabHelper::CreateForWebState(&first_web_state_);
+  TabIDTabHelper::CreateForWebState(&second_web_state_);
+
+  const NSString* first_tab_id =
+      TabIDTabHelper::FromWebState(&first_web_state_)->tab_id();
+  const NSString* second_tab_id =
+      TabIDTabHelper::FromWebState(&second_web_state_)->tab_id();
+
+  EXPECT_GT([first_tab_id length], 0U);
+  EXPECT_GT([second_tab_id length], 0U);
+  EXPECT_NSNE(first_tab_id, second_tab_id);
+}

[sdefresne, 2017/06/26 10:28:55]

Maybe test that the TabID is stable across calls, i.e. that successive calls to
tab_id() on the same object return the same value. I was broken at some point
for deserialized objects and caused a RBS.

[edchin, 2017/06/26 16:20:57]

Will do.