📰 Stop refreshing the whole NTP for every adapter change

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

Index: chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SuggestionsSectionTest.java
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SuggestionsSectionTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SuggestionsSectionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..819224457791d8f3ff798744295c12491a5bad80
--- /dev/null
+++ b/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SuggestionsSectionTest.java
@@ -0,0 +1,144 @@
+// Copyright 2016 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.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.createDummySuggestions;
+import static org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.createInfo;
+import static org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.createSection;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.anyInt;
+import static org.mockito.Mockito.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import org.chromium.base.test.util.Feature;
+import org.chromium.chrome.browser.ntp.snippets.CategoryStatus;
+import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+
+import java.util.List;
+
+/**
+ * Unit tests for {@link SuggestionsSection}.
+ */
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class SuggestionsSectionTest {
+    /** Number of items in a section when there are no suggestions: header, status, progress. */
+    private static final int EMPTY_SECTION_COUNT = 3;
+
+    @Test
+    @Feature({"Ntp"})
+    public void testDismissSibling() {
+        ItemGroup.Observer observerMock = mock(ItemGroup.Observer.class);
+        List<SnippetArticle> snippets = createDummySuggestions(3);
+        SuggestionsSection section;
+
+        // Part 1: ShowMoreButton = true.
+        section = new SuggestionsSection(42, createInfo(true, true), observerMock, null);
+        section.setStatus(CategoryStatus.AVAILABLE);
+        assertNotNull(section.getActionItem());
+
+        // 1.1: Without snippets.
+        assertEquals(-1, section.getDismissSiblingPosDelta(section.getActionItem()));
+        assertEquals(1, section.getDismissSiblingPosDelta(section.getStatusItem()));
+
+        // 1.2: With snippets.
+        section.setSuggestions(snippets, CategoryStatus.AVAILABLE);
+        assertEquals(0, section.getDismissSiblingPosDelta(section.getActionItem()));
+        assertEquals(0, section.getDismissSiblingPosDelta(section.getStatusItem()));
+        assertEquals(0, section.getDismissSiblingPosDelta(snippets.get(0)));
+
+        // Part 2: ShowMoreButton = false.
+        section = new SuggestionsSection(42, createInfo(false, true), observerMock, null);
+        section.setStatus(CategoryStatus.AVAILABLE);
+        assertNull(section.getActionItem());
+
+        // 2.1: Without snippets.
+        assertEquals(0, section.getDismissSiblingPosDelta(section.getStatusItem()));
+
+        // 2.2: With snippets.
+        section.setSuggestions(snippets, CategoryStatus.AVAILABLE);
+        assertEquals(0, section.getDismissSiblingPosDelta(section.getStatusItem()));
+        assertEquals(0, section.getDismissSiblingPosDelta(snippets.get(0)));
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testSetSuggestionsNotification() {
+        ItemGroup.Observer observerMock = mock(ItemGroup.Observer.class);
+
+        final int suggestionCount = 5;
+        List<SnippetArticle> snippets = createDummySuggestions(suggestionCount);
+
+        SuggestionsSection section = createSection(false, true, observerMock);
+        // Note: when status is not initialised, we insert an item for the status card, but it's
+        // null!
+        assertEquals(EMPTY_SECTION_COUNT, section.getItems().size());
+
+        section.setSuggestions(snippets, CategoryStatus.AVAILABLE);
+        verify(observerMock)
+                .notifyGroupChanged(
+                        eq(section), eq(EMPTY_SECTION_COUNT), eq(suggestionCount + 1 /* header */));
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testSetStatusNotification() {
+        ItemGroup.Observer observerMock = mock(ItemGroup.Observer.class);
+        final int emptySectionCount = 3;
+        final int suggestionCount = 5;
+        List<SnippetArticle> snippets = createDummySuggestions(suggestionCount);
+
+        SuggestionsSection section = createSection(false, true, observerMock);
+
+        section.setStatus(CategoryStatus.AVAILABLE);
+        verify(observerMock)
+                .notifyGroupChanged(eq(section), eq(EMPTY_SECTION_COUNT), eq(EMPTY_SECTION_COUNT));
+
+        section.setSuggestions(snippets, CategoryStatus.AVAILABLE);
+
+        // We don't clear suggestions when the status is AVAILABLE.
+        section.setStatus(CategoryStatus.AVAILABLE);
+        verify(observerMock)
+                .notifyGroupChanged(eq(section), eq(suggestionCount + 1), eq(suggestionCount + 1));
+
+        // We clear existing suggestions when the status is not AVAILABLE.
+        section.setStatus(CategoryStatus.LOADING_ERROR);
+        verify(observerMock)
+                .notifyGroupChanged(eq(section), eq(suggestionCount + 1), eq(EMPTY_SECTION_COUNT));
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testRemoveSuggestionNotification() {
+        ItemGroup.Observer observerMock = mock(ItemGroup.Observer.class);
+
+        final int suggestionCount = 2;
+        List<SnippetArticle> snippets = createDummySuggestions(suggestionCount);
+
+        SuggestionsSection section = createSection(false, true, observerMock);
+
+        section.removeSuggestion(snippets.get(0));
+        verify(observerMock, never()).notifyGroupChanged(any(ItemGroup.class), anyInt(), anyInt());
+        verify(observerMock, never()).notifyItemRemoved(any(ItemGroup.class), anyInt());
+
+        section.setSuggestions(snippets, CategoryStatus.AVAILABLE);
+
+        section.removeSuggestion(snippets.get(0));
+        verify(observerMock).notifyItemRemoved(section, 1);
+
+        section.removeSuggestion(snippets.get(1));
+        verify(observerMock)
+                .notifyGroupChanged(section, 2 /* header + suggestion */, EMPTY_SECTION_COUNT);
+    }
+}