📰 Tweak the suggestion ranks for UMA to handle fetchMore

chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java

Index: chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..c23b99c6cd796eb2e7ccbd0d2cd34fbdc92b95e1
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+++ b/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java
@@ -0,0 +1,155 @@
+// 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.
+
+package org.chromium.chrome.browser.ntp.cards;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.when;
+
+import static org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.createDummySuggestions;
+import static org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.registerCategory;
+
+import android.util.Pair;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+import org.robolectric.annotation.RealObject;
+
+import org.chromium.base.test.util.Feature;
+import org.chromium.chrome.browser.ntp.NewTabPageView.NewTabPageManager;
+import org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.CategoryInfoBuilder;
+import org.chromium.chrome.browser.ntp.cards.SectionListTest.ShadowPair;
+import org.chromium.chrome.browser.ntp.snippets.FakeSuggestionsSource;
+import org.chromium.chrome.browser.ntp.snippets.KnownCategories;
+import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
+import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
+import org.chromium.chrome.browser.suggestions.SuggestionsMetricsReporter;
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+
+import java.util.List;
+import java.util.Locale;
+
+/**
+ * Unit tests for {@link SuggestionsSection}.
+ */
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE, shadows = {ShadowPair.class})
+public class SectionListTest {
+    @Mock
+    private NewTabPageManager mNtpManager;
+    @Mock
+    private OfflinePageBridge mOfflinePageBridge;
+    @Mock
+    private SuggestionsMetricsReporter mMetricsReporter;
+    private FakeSuggestionsSource mSuggestionSource;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mSuggestionSource = new FakeSuggestionsSource();
+
+        when(mNtpManager.getSuggestionsSource()).thenReturn(mSuggestionSource);
+        when(mNtpManager.getSuggestionsMetricsReporter()).thenReturn(mMetricsReporter);
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testGetSuggestionRank() {
+        // Setup the section list the following way:
+        //
+        //  Item type | local rank | global rank
+        // -----------+------------+-------------
+        // HEADER     |            |
+        // ARTICLE    | 0          | 0
+        // ARTICLE    | 1          | 1
+        // ARTICLE    | 2          | 2
+        // HEADER     |            |
+        // STATUS     |            |
+        // ACTION     | 0          |
+        // BOOKMARK   | 0          | 3
+        // BOOKMARK   | 1          | 4
+        // BOOKMARK   | 2          | 5
+        // BOOKMARK   | 3          | 6
+        List<SnippetArticle> articles =
+                registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 3);
+        registerCategory(mSuggestionSource, KnownCategories.DOWNLOADS, 0);
+        List<SnippetArticle> bookmarks =
+                registerCategory(mSuggestionSource, KnownCategories.BOOKMARKS, 4);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+
+        assertThat(sectionList.getSuggestionRank(articles.get(0)), equalTo(new Pair<>(0, 0)));
+        assertThat(sectionList.getSuggestionRank(articles.get(2)), equalTo(new Pair<>(2, 2)));
+        assertThat(sectionList.getSuggestionRank(bookmarks.get(1)), equalTo(new Pair<>(1, 4)));
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    @Feature({"Ntp"})
+    public void testGetSuggestionRankWithUnregisteredCategory() {
+        registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 3);
+        SnippetArticle unregisteredSuggestion =
+                createDummySuggestions(1, KnownCategories.DOWNLOADS).get(0);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+
+        sectionList.getSuggestionRank(unregisteredSuggestion);
+    }
+
+    @Test(expected = AssertionError.class)
+    @Feature({"Ntp"})
+    public void testGetSuggestionRankWithUnregisteredSuggestion() {
+        registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 3);
+        SnippetArticle unregisteredSuggestion =
+                createDummySuggestions(5, KnownCategories.ARTICLES).get(4);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+
+        sectionList.getSuggestionRank(unregisteredSuggestion);
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testGetActionItemRank() {
+        registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 0);
+        registerCategory(mSuggestionSource,
+                new CategoryInfoBuilder(KnownCategories.DOWNLOADS).withViewAllAction().build(), 3);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+
+        assertThat(sectionList.getActionItemRank(KnownCategories.ARTICLES), equalTo(0));
+        assertThat(sectionList.getActionItemRank(KnownCategories.DOWNLOADS), equalTo(3));
+    }
+
+    @Test(expected = AssertionError.class)
+    @Feature({"Ntp"})
+    public void testGetActionItemRankWhenInvisible() {
+        registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 3);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+
+        sectionList.getActionItemRank(KnownCategories.ARTICLES);
+    }
+
+    /**
+     * Shadow for {@link Pair} that allows to overriding {@link Pair#toString()} to make it useful
+     * in test failure messages.
+     */
+    @Implements(Pair.class)
+    public static class ShadowPair {
+        @RealObject
+        private Pair mRealPair;
+
+        @Implementation
+        public String toString() {
+            return String.format(Locale.US, "{%s, %s}", mRealPair.first, mRealPair.second);
+        }
+    }
+}