Add Category wrapper for ContentSuggestions on iOS

ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper_unittest.mm

Index: ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper_unittest.mm
diff --git a/ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper_unittest.mm b/ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper_unittest.mm
new file mode 100644
index 0000000000000000000000000000000000000000..9f06ba86ec53ecfa79cab4483cee9ea17678a384
--- /dev/null
+++ b/ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper_unittest.mm
@@ -0,0 +1,49 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.

[stkhapugin, 2017/02/13 12:19:18]

Excellent unit tests, thank you. 

[gambard, 2017/02/13 14:51:41]

:)

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper.h"
+
+#include "components/ntp_snippets/category.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// Tests that the category returned by the wrapper is the one given in the
+// initializer.
+TEST(ContentSuggestionsCategoryWrapperTest, GetCategory) {
+  ntp_snippets::Category category = ntp_snippets::Category::FromIDValue(2);
+  ContentSuggestionsCategoryWrapper* wrapper =
+      [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category];
+
+  EXPECT_EQ(category, wrapper.category);
+}
+
+// Tests that two wrappers created with equal categories are equal.
+TEST(ContentSuggestionsCategoryWrapperTest, AreWrappersEqual) {
+  ntp_snippets::Category category = ntp_snippets::Category::FromIDValue(2);
+  ContentSuggestionsCategoryWrapper* wrapper =
+      [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category];
+  ntp_snippets::Category category2 = ntp_snippets::Category::FromIDValue(2);
+  ContentSuggestionsCategoryWrapper* wrapper2 =
+      [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category2];
+  ASSERT_EQ(category, category2);
+
+  EXPECT_TRUE([wrapper isEqual:wrapper2]);
+  EXPECT_EQ(wrapper.hash, wrapper2.hash);
+}
+
+// Tests that two wrappers created with different categories are not equal.
+TEST(ContentSuggestionsCategoryWrapperTest, AreWrappersDifferent) {
+  ntp_snippets::Category category = ntp_snippets::Category::FromIDValue(2);
+  ContentSuggestionsCategoryWrapper* wrapper =
+      [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category];
+  ntp_snippets::Category category2 = ntp_snippets::Category::FromIDValue(3);
+  ContentSuggestionsCategoryWrapper* wrapper2 =
+      [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category2];
+  ASSERT_NE(category, category2);
+
+  EXPECT_FALSE([wrapper isEqual:wrapper2]);
+}

[lpromero, 2017/02/13 12:34:55]

Add a test that exercises the class check in the isEqual: implementation.
Compare a Wrapper and an NSObject for example, or more involved stuff like
subclassing.

[gambard, 2017/02/13 14:51:41]

Done.