Add test of MakeUniqueID() and friends.

components/ntp_snippets/content_suggestions_provider_unittest.cc

Index: components/ntp_snippets/content_suggestions_provider_unittest.cc
diff --git a/components/ntp_snippets/content_suggestions_provider_unittest.cc b/components/ntp_snippets/content_suggestions_provider_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e84d72fba2f38801290b84da14d143d6e00ee8bc
--- /dev/null
+++ b/components/ntp_snippets/content_suggestions_provider_unittest.cc
@@ -0,0 +1,112 @@
+// Copyright 2015 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/content_suggestions_provider.h"
+
+#include "base/callback.h"
+#include "components/ntp_snippets/category_factory.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using testing::Eq;
+using testing::StrictMock;
+
+namespace ntp_snippets {
+
+// We do not care about any of these methods. We use mock methods so that we can
+// declare a StrictMock below and ensure none of them are called.
+class MockContentSuggestionsProvider : public ContentSuggestionsProvider {
+ public:
+  MockContentSuggestionsProvider(Observer* observer,
+                                 CategoryFactory* category_factory)
+      : ContentSuggestionsProvider(observer, category_factory) {}
+  virtual ~MockContentSuggestionsProvider() = default;
+
+  MOCK_METHOD1(GetCategoryStatus, CategoryStatus(Category));
+  MOCK_METHOD1(GetCategoryInfo, CategoryInfo(Category));
+  MOCK_METHOD1(DismissSuggestion, void(const std::string&));
+  MOCK_METHOD2(FetchSuggestionImage,
+               void(const std::string&, const ImageFetchedCallback&));
+  MOCK_METHOD3(ClearHistory,
+               void(base::Time,
+                    base::Time,
+                    const base::Callback<bool(const GURL&)>&));
+  MOCK_METHOD1(ClearCachedSuggestions, void(Category));
+  MOCK_METHOD2(GetDismissedSuggestionsForDebugging,
+               void(Category, const DismissedSuggestionsCallback&));
+  MOCK_METHOD1(ClearDismissedSuggestionsForDebugging, void(Category));
+};
+
+class ContentSuggestionsProviderTest : public ::testing::Test {
+ protected:
+  ContentSuggestionsProviderTest() : provider_(nullptr, &factory_) {}
+
+  std::string MakeUniqueID(Category category,
+                           const std::string& within_category_id) const {
+    return provider_.MakeUniqueID(category, within_category_id);
+  }
+
+  Category GetCategoryFromUniqueID(const std::string& unique_id) const {
+    return provider_.GetCategoryFromUniqueID(unique_id);
+  }
+
+  std::string GetWithinCategoryIDFromUniqueID(
+      const std::string& unique_id) const {
+    return provider_.GetWithinCategoryIDFromUniqueID(unique_id);
+  }
+
+  StrictMock<MockContentSuggestionsProvider> provider_;
+  CategoryFactory factory_;

[Marc Treib, 2016/09/02 12:43:25]

nit: swap these two, so the provider gets deleted before the factory

[sfiera, 2016/09/02 12:49:23]

Done.

+};
+
+TEST_F(ContentSuggestionsProviderTest, Articles) {
+  Category kArticles = factory_.FromKnownCategory(KnownCategories::ARTICLES);
+  const std::string kUrl = "https://chromium.org/";
+
+  std::string uid = MakeUniqueID(kArticles, kUrl);
+  EXPECT_THAT(uid, Eq("10001|https://chromium.org/"));
+  EXPECT_THAT(GetCategoryFromUniqueID(uid), Eq(kArticles));
+  EXPECT_THAT(GetWithinCategoryIDFromUniqueID(uid), Eq(kUrl));
+}
+
+TEST_F(ContentSuggestionsProviderTest, Remote) {
+  Category kRemoteCategory = factory_.FromRemoteCategory(2);
+  const std::string kUrl = "https://chromium.org/";
+
+  std::string uid = MakeUniqueID(kRemoteCategory, kUrl);
+  EXPECT_THAT(uid, Eq("10002|https://chromium.org/"));
+  EXPECT_THAT(GetCategoryFromUniqueID(uid), Eq(kRemoteCategory));
+  EXPECT_THAT(GetWithinCategoryIDFromUniqueID(uid), Eq(kUrl));
+}
+
+TEST_F(ContentSuggestionsProviderTest, FromID) {
+  Category kCategory = factory_.FromIDValue(10003);
+  const std::string kUrl = "https://chromium.org/";
+
+  std::string uid = MakeUniqueID(kCategory, kUrl);
+  EXPECT_THAT(uid, Eq("10003|https://chromium.org/"));
+  EXPECT_THAT(GetCategoryFromUniqueID(uid), Eq(kCategory));
+  EXPECT_THAT(GetWithinCategoryIDFromUniqueID(uid), Eq(kUrl));
+}
+
+TEST_F(ContentSuggestionsProviderTest, Death) {
+  const std::string kUrl = "https://chromium.org/";
+#if DCHECK_IS_ON()
+  EXPECT_DEATH(GetCategoryFromUniqueID(kUrl), "Not a valid unique_id");
+  EXPECT_DEATH(GetWithinCategoryIDFromUniqueID(kUrl), "Not a valid unique_id");
+
+  EXPECT_DEATH(GetCategoryFromUniqueID("one|" + kUrl), "Non-numeric category");
+  EXPECT_THAT(GetWithinCategoryIDFromUniqueID("one|" + kUrl), Eq(kUrl));
+#else
+  const Category kNoCategory = factory_.FromIDValue(-1);
+
+  EXPECT_THAT(GetCategoryFromUniqueID(kUrl), Eq(kNoCategory));

[Marc Treib, 2016/09/02 12:43:25]

Is the DCHECK-off part here for any particular reason, as in, are you
investigating something in particular? If not, I'd argue that this is not
something we want to test.

[sfiera, 2016/09/02 12:49:23]

Nothing in particular.

But why wouldn't we want to test it? The idea of using DCHECK() instead of
CHECK() is that we should continue to function in a release build, right? Isn't
this branch the *more* important of the two?

[Marc Treib, 2016/09/02 13:02:02]

No, DCHECKS are treated like asserts, i.e. something that can *never* happen.
They're essentially documentation. We're so sure of that that we don't even want
to pay the performance cost for the check in release builds.
The code style guide used to say something to that effect, but I can't seem to
find it right now.

[grt (UTC plus 2), 2016/09/02 19:21:47]

I think you're looking for this:
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md...

+  EXPECT_THAT(GetWithinCategoryIDFromUniqueID(kUrl), Eq(kUrl));
+
+  EXPECT_THAT(GetCategoryFromUniqueID("one|" + kUrl), Eq(kNoCategory));
+  EXPECT_THAT(GetWithinCategoryIDFromUniqueID("one|" + kUrl), Eq(kUrl));
+#endif
+}
+
+}  // namespace ntp_snippets