Unify NewTabPageItem and ItemGroup into a single tree-structured interface.

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

+// 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.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+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.chromium.chrome.browser.ntp.snippets.SnippetArticle;
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * JUnit tests for {@link InnerNode}.
+ */
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class InnerNodeTest {
+
+    private static final int[] ITEM_COUNTS = {1, 2, 3, 0, 3, 2, 1};
+    private final List<TreeNode> mChildren = Arrays.asList(new TreeNode[ITEM_COUNTS.length]);
+    @Mock private NodeParent mParent;
+    private InnerNode mInnerNode;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        for (int i = 0; i < ITEM_COUNTS.length; i++) {
+            TreeNode child = mock(TreeNode.class);
+            when(child.getItemCount()).thenReturn(ITEM_COUNTS[i]);
+            mChildren.set(i, child);
+        }
+        mInnerNode = new InnerNode(mParent) {
+            @Override
+            protected List<TreeNode> getChildren() {
+                return mChildren;
+            }
+        };
+    }
+
+    @Test
+    public void testItemCount() {
+        assertThat(mInnerNode.getItemCount(), is(12));
+    }
+
+    @Test
+    public void testGetItemViewType() {
+        when(mChildren.get(0).getItemViewType(0)).thenReturn(42);
+        when(mChildren.get(2).getItemViewType(2)).thenReturn(23);
+        when(mChildren.get(4).getItemViewType(0)).thenReturn(4711);
+        when(mChildren.get(6).getItemViewType(0)).thenReturn(1729);
+
+        assertThat(mInnerNode.getItemViewType(0), is(42));
+        assertThat(mInnerNode.getItemViewType(5), is(23));
+        assertThat(mInnerNode.getItemViewType(6), is(4711));
+        assertThat(mInnerNode.getItemViewType(11), is(1729));
+    }
+
+    @Test
+    public void testBindViewHolder() {
+        NewTabPageViewHolder holder = mock(NewTabPageViewHolder.class);
+        mInnerNode.onBindViewHolder(holder, 0);
+        mInnerNode.onBindViewHolder(holder, 5);
+        mInnerNode.onBindViewHolder(holder, 6);
+        mInnerNode.onBindViewHolder(holder, 11);
+
+        verify(mChildren.get(0)).onBindViewHolder(holder, 0);
+        verify(mChildren.get(2)).onBindViewHolder(holder, 2);
+        verify(mChildren.get(4)).onBindViewHolder(holder, 0);
+        verify(mChildren.get(6)).onBindViewHolder(holder, 0);
+    }
+
+    @Test
+    public void testGetSuggestion() {
+        SnippetArticle article1 = mock(SnippetArticle.class);
+        SnippetArticle article2 = mock(SnippetArticle.class);
+        SnippetArticle article3 = mock(SnippetArticle.class);
+        SnippetArticle article4 = mock(SnippetArticle.class);
+
+        when(mChildren.get(0).getSuggestionAt(0)).thenReturn(article1);
+        when(mChildren.get(2).getSuggestionAt(2)).thenReturn(article2);
+        when(mChildren.get(4).getSuggestionAt(0)).thenReturn(article3);
+        when(mChildren.get(6).getSuggestionAt(0)).thenReturn(article4);
+
+        assertThat(mInnerNode.getSuggestionAt(0), is(article1));
+        assertThat(mInnerNode.getSuggestionAt(5), is(article2));
+        assertThat(mInnerNode.getSuggestionAt(6), is(article3));
+        assertThat(mInnerNode.getSuggestionAt(11), is(article4));
+    }
+
+    @Test
+    public void testNotifications() {
+        mInnerNode.onItemRangeInserted(mChildren.get(0), 0, 23);
+        mInnerNode.onItemRangeChanged(mChildren.get(2), 2, 9000);
+        mInnerNode.onItemRangeChanged(mChildren.get(4), 0, 6502);
+        mInnerNode.onItemRangeRemoved(mChildren.get(6), 0, 8086);
+
+        verify(mParent).onItemRangeInserted(mInnerNode, 0, 23);
+        verify(mParent).onItemRangeChanged(mInnerNode, 5, 9000);
+        verify(mParent).onItemRangeChanged(mInnerNode, 6, 6502);
+        verify(mParent).onItemRangeRemoved(mInnerNode, 11, 8086);
+    }
+}
+