[ios] Unittest for TabGridMediator.

BUG=none

Review-Url: https://codereview.chromium.org/2792823002
Cr-Commit-Position: refs/heads/master@{#462882}

ios/clean/chrome/browser/ui/tab_grid/BUILD.gn

@@ -65,3 +65,26 @@ source_set("tab_grid_ui") {
     "//ui/base",
   ]
 }
+
+source_set("unit_tests") {
+  testonly = true
+
+  sources = [
+    "tab_grid_mediator_unittest.mm",
+  ]
+
+  configs += [ "//build/config/compiler:enable_arc" ]
+
+  deps = [
+    ":tab_grid",
+    ":tab_grid_ui",
+    "//base",
+    "//base/test:test_support",
+    "//ios/chrome/test/base",
+    "//ios/shared/chrome/browser/tabs",
+    "//ios/shared/chrome/browser/tabs:test_support",
+    "//ios/web:test_support",
+    "//testing/gtest",
+    "//third_party/ocmock",
+  ]
+}

ios/clean/chrome/browser/ui/tab_grid/tab_grid_mediator.mm

@@ -4,9 +4,7 @@
 
 #import "ios/clean/chrome/browser/ui/tab_grid/tab_grid_mediator.h"
 
-#include "base/memory/ptr_util.h"
-#include "base/strings/sys_string_conversions.h"
-#import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_consumer.h"
+#import "ios/clean/chrome/browser/ui/tab_grid/tab_grid_consumer.h"
 #import "ios/shared/chrome/browser/tabs/web_state_list.h"
 #import "ios/shared/chrome/browser/tabs/web_state_list_observer_bridge.h"
 #include "ios/web/public/web_state/web_state.h"

ios/clean/chrome/browser/ui/tab_grid/tab_grid_mediator_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/clean/chrome/browser/ui/tab_grid/tab_grid_mediator.h"
+
+#include "base/memory/ptr_util.h"
+#import "ios/clean/chrome/browser/ui/tab_grid/tab_grid_consumer.h"
+#include "ios/shared/chrome/browser/tabs/fake_web_state_list_delegate.h"
+#include "ios/shared/chrome/browser/tabs/web_state_list.h"
+#import "ios/shared/chrome/browser/tabs/web_state_list_observer_bridge.h"
+#import "ios/web/public/test/fakes/test_navigation_manager.h"
+#import "ios/web/public/test/fakes/test_web_state.h"
+#include "testing/platform_test.h"
+#import "third_party/ocmock/OCMock/OCMock.h"
+#include "third_party/ocmock/gtest_support.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+
+class TabGridMediatorTest : public PlatformTest {
+ public:
+  TabGridMediatorTest() {
+    SetUpEmptyWebStateList();
+    mediator_ = [[TabGridMediator alloc] init];
+    mediator_.webStateList = web_state_list_.get();
+  }
+  ~TabGridMediatorTest() override { [mediator_ disconnect]; }
+
+ protected:
+  void SetUpEmptyWebStateList() {
+    web_state_list_ = base::MakeUnique<WebStateList>(&web_state_list_delegate_);
+  }
+
+  void InsertWebStateAt(int index) {
+    auto web_state = base::MakeUnique<web::TestWebState>();
+    web_state_list_->InsertWebState(index, std::move(web_state));
+  }
+
+  void SetConsumer() {
+    consumer_ = [OCMockObject mockForProtocol:@protocol(TabGridConsumer)];
+    mediator_.consumer = consumer_;
+  }
+
+  TabGridMediator* mediator_;
+  std::unique_ptr<WebStateList> web_state_list_;
+  FakeWebStateListDelegate web_state_list_delegate_;
+  id consumer_;
+};
+
+// Tests that the noTabsOverlay is removed when a web state is inserted when
+// the list is empty.
+TEST_F(TabGridMediatorTest, TestRemoveNoTabsOverlay) {
+  SetConsumer();
+  [[consumer_ expect] insertItemAtIndex:0];
+  [[consumer_ expect] removeNoTabsOverlay];
+  InsertWebStateAt(0);
+  EXPECT_OCMOCK_VERIFY(consumer_);
+}
+
+// Tests that the noTabsOverlay is added when the web state list becomes empty.
+TEST_F(TabGridMediatorTest, TestAddNoTabsOverlay) {
+  InsertWebStateAt(0);
+  SetConsumer();
+  [[consumer_ expect] deleteItemAtIndex:0];
+  [[consumer_ expect] addNoTabsOverlay];
+  web_state_list_->CloseWebStateAt(0);
+  EXPECT_OCMOCK_VERIFY(consumer_);
+}
+
+}  // namespace

ios/clean/chrome/test/BUILD.gn

@@ -22,6 +22,7 @@ test("ios_clean_chrome_unittests") {
     "//ios/clean/chrome/browser/ui/context_menu:unit_tests",
     "//ios/clean/chrome/browser/ui/omnibox:unit_tests",
     "//ios/clean/chrome/browser/ui/tab_collection:unit_tests",
+    "//ios/clean/chrome/browser/ui/tab_grid:unit_tests",
     "//ios/clean/chrome/browser/ui/web_contents:unit_tests",
   ]
 }