diff --git a/tests/Android.bp b/tests/Android.bp
index 37231f9..aeddc4c 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -56,6 +56,7 @@
     resource_dirs: ["res"],
     static_libs: [
         "launcher-aosp-tapl",
+        "androidx.test.core",
         "androidx.test.runner",
         "androidx.test.rules",
         "androidx.test.ext.junit",
diff --git a/tests/src/com/android/launcher3/util/ActivityContextWrapper.java b/tests/src/com/android/launcher3/util/ActivityContextWrapper.java
new file mode 100644
index 0000000..2618a2e
--- /dev/null
+++ b/tests/src/com/android/launcher3/util/ActivityContextWrapper.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.util;
+
+import android.content.Context;
+import android.content.ContextWrapper;
+import android.view.ContextThemeWrapper;
+
+import com.android.launcher3.DeviceProfile;
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.views.ActivityContext;
+import com.android.launcher3.views.BaseDragLayer;
+
+/**
+ * {@link ContextWrapper} with internal Launcher interface for testing
+ */
+public class ActivityContextWrapper extends ContextThemeWrapper implements ActivityContext {
+
+    private final DeviceProfile mProfile;
+    private final MyDragLayer mMyDragLayer;
+
+    public ActivityContextWrapper(Context base) {
+        super(base, android.R.style.Theme_DeviceDefault);
+        mProfile = InvariantDeviceProfile.INSTANCE.get(base).getDeviceProfile(base).copy(base);
+        mMyDragLayer = new MyDragLayer(this);
+    }
+
+    @Override
+    public BaseDragLayer getDragLayer() {
+        return mMyDragLayer;
+    }
+
+    @Override
+    public DeviceProfile getDeviceProfile() {
+        return mProfile;
+    }
+
+    private static class MyDragLayer extends BaseDragLayer<ActivityContextWrapper> {
+
+        MyDragLayer(Context context) {
+            super(context, null, 1);
+        }
+
+        @Override
+        public void recreateControllers() {
+            mControllers = new TouchController[0];
+        }
+    }
+}
diff --git a/tests/src/com/android/launcher3/util/WidgetUtils.java b/tests/src/com/android/launcher3/util/WidgetUtils.java
index 7bc752e..6fc8491 100644
--- a/tests/src/com/android/launcher3/util/WidgetUtils.java
+++ b/tests/src/com/android/launcher3/util/WidgetUtils.java
@@ -15,12 +15,19 @@
  */
 package com.android.launcher3.util;
 
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
+
 import static com.android.launcher3.WorkspaceLayoutManager.FIRST_SCREEN_ID;
 
 import android.appwidget.AppWidgetHost;
+import android.appwidget.AppWidgetManager;
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.os.Bundle;
+import android.os.Process;
 
 import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.model.data.ItemInfo;
@@ -101,4 +108,17 @@
         resolver.insert(LauncherSettings.Favorites.CONTENT_URI,
                 writer.getValues(targetContext));
     }
+
+
+    /**
+     * Creates a {@link AppWidgetProviderInfo} for the provided component name
+     */
+    public static AppWidgetProviderInfo createAppWidgetProviderInfo(ComponentName cn) {
+        AppWidgetProviderInfo info = AppWidgetManager.getInstance(getApplicationContext())
+                .getInstalledProvidersForPackage(
+                        getInstrumentation().getContext().getPackageName(), Process.myUserHandle())
+                .get(0);
+        info.provider = cn;
+        return info;
+    }
 }
diff --git a/tests/src/com/android/launcher3/widget/LauncherAppWidgetProviderInfoTest.java b/tests/src/com/android/launcher3/widget/LauncherAppWidgetProviderInfoTest.java
new file mode 100644
index 0000000..24ae583
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/LauncherAppWidgetProviderInfoTest.java
@@ -0,0 +1,275 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+
+import android.appwidget.AppWidgetHostView;
+import android.content.Context;
+import android.graphics.Point;
+import android.graphics.Rect;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.DeviceProfile;
+import com.android.launcher3.InvariantDeviceProfile;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mockito;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class LauncherAppWidgetProviderInfoTest {
+
+    private static final int CELL_SIZE = 50;
+    private static final int NUM_OF_COLS = 4;
+    private static final int NUM_OF_ROWS = 5;
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = getApplicationContext();
+    }
+
+    @Test
+    public void initSpans_minWidthSmallerThanCellWidth_shouldInitializeSpansToOne() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 20;
+        info.minHeight = 20;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.spanX).isEqualTo(1);
+        assertThat(info.spanY).isEqualTo(1);
+    }
+
+    @Test
+    public void initSpans_minWidthLargerThanCellWidth_shouldInitializeSpans() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 80;
+        info.minHeight = 80;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.spanX).isEqualTo(2);
+        assertThat(info.spanY).isEqualTo(2);
+    }
+
+    @Test
+    public void
+            initSpans_minWidthLargerThanGridColumns_shouldInitializeSpansToAtMostTheGridColumns() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = CELL_SIZE * (NUM_OF_COLS + 1);
+        info.minHeight = 20;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.spanX).isEqualTo(NUM_OF_COLS);
+        assertThat(info.spanY).isEqualTo(1);
+    }
+
+    @Test
+    public void initSpans_minHeightLargerThanGridRows_shouldInitializeSpansToAtMostTheGridRows() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 20;
+        info.minHeight = 50 * (NUM_OF_ROWS + 1);
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.spanX).isEqualTo(1);
+        assertThat(info.spanY).isEqualTo(NUM_OF_ROWS);
+    }
+
+    @Test
+    public void initSpans_minResizeWidthUnspecified_shouldInitializeMinSpansToOne() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.minSpanX).isEqualTo(1);
+        assertThat(info.minSpanY).isEqualTo(1);
+    }
+
+    @Test
+    public void initSpans_minResizeWidthSmallerThanCellWidth_shouldInitializeMinSpansToOne() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 100;
+        info.minHeight = 100;
+        info.minResizeWidth = 20;
+        info.minResizeHeight = 20;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.minSpanX).isEqualTo(1);
+        assertThat(info.minSpanY).isEqualTo(1);
+    }
+
+    @Test
+    public void initSpans_minResizeWidthLargerThanCellWidth_shouldInitializeMinSpans() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 100;
+        info.minHeight = 100;
+        info.minResizeWidth = 80;
+        info.minResizeHeight = 80;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.minSpanX).isEqualTo(2);
+        assertThat(info.minSpanY).isEqualTo(2);
+    }
+
+    @Test
+    public void initSpans_minResizeWidthWithCellSpacingAndWidgetInset_shouldInitializeMinSpans() {
+        InvariantDeviceProfile idp = createIDP();
+        DeviceProfile dp = idp.supportedProfiles.get(0);
+        Rect padding = new Rect();
+        AppWidgetHostView.getDefaultPaddingForWidget(mContext, null, padding);
+        int maxPadding = Math.max(Math.max(padding.left, padding.right),
+                Math.max(padding.top, padding.bottom));
+        dp.cellLayoutBorderSpacingPx = maxPadding + 1;
+        Mockito.when(dp.shouldInsetWidgets()).thenReturn(true);
+
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = CELL_SIZE * 3;
+        info.minHeight = CELL_SIZE * 3;
+        info.minResizeWidth = CELL_SIZE * 2 + maxPadding;
+        info.minResizeHeight = CELL_SIZE * 2 + maxPadding;
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.minSpanX).isEqualTo(2);
+        assertThat(info.minSpanY).isEqualTo(2);
+    }
+
+    @Test
+    public void initSpans_minResizeWidthWithCellSpacingAndNoWidgetInset_shouldInitializeMinSpans() {
+        InvariantDeviceProfile idp = createIDP();
+        DeviceProfile dp = idp.supportedProfiles.get(0);
+        Rect padding = new Rect();
+        AppWidgetHostView.getDefaultPaddingForWidget(mContext, null, padding);
+        int maxPadding = Math.max(Math.max(padding.left, padding.right),
+                Math.max(padding.top, padding.bottom));
+        dp.cellLayoutBorderSpacingPx = maxPadding - 1;
+        Mockito.when(dp.shouldInsetWidgets()).thenReturn(false);
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = CELL_SIZE * 3;
+        info.minHeight = CELL_SIZE * 3;
+        info.minResizeWidth = CELL_SIZE * 2 + maxPadding;
+        info.minResizeHeight = CELL_SIZE * 2 + maxPadding;
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.minSpanX).isEqualTo(3);
+        assertThat(info.minSpanY).isEqualTo(3);
+    }
+
+    @Test
+    public void
+            initSpans_minResizeWidthHeightLargerThanMinWidth_shouldUseMinWidthHeightAsMinSpans() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 20;
+        info.minHeight = 20;
+        info.minResizeWidth = 80;
+        info.minResizeHeight = 80;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.minSpanX).isEqualTo(1);
+        assertThat(info.minSpanY).isEqualTo(1);
+    }
+
+    @Test
+    public void isMinSizeFulfilled_minWidthAndHeightWithinGridSize_shouldReturnTrue() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 80;
+        info.minHeight = 80;
+        info.minResizeWidth = 50;
+        info.minResizeHeight = 50;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.isMinSizeFulfilled()).isTrue();
+    }
+
+    @Test
+    public void
+            isMinSizeFulfilled_minWidthAndMinResizeWidthExceededGridColumns_shouldReturnFalse() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = CELL_SIZE * (NUM_OF_COLS + 2);
+        info.minHeight = 80;
+        info.minResizeWidth = CELL_SIZE * (NUM_OF_COLS + 1);
+        info.minResizeHeight = 50;
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.isMinSizeFulfilled()).isFalse();
+    }
+
+    @Test
+    public void isMinSizeFulfilled_minHeightAndMinResizeHeightExceededGridRows_shouldReturnFalse() {
+        LauncherAppWidgetProviderInfo info = new LauncherAppWidgetProviderInfo();
+        info.minWidth = 80;
+        info.minHeight = CELL_SIZE * (NUM_OF_ROWS + 2);
+        info.minResizeWidth = 50;
+        info.minResizeHeight = CELL_SIZE * (NUM_OF_ROWS + 1);
+        InvariantDeviceProfile idp = createIDP();
+
+        info.initSpans(mContext, idp);
+
+        assertThat(info.isMinSizeFulfilled()).isFalse();
+    }
+
+    private InvariantDeviceProfile createIDP() {
+        DeviceProfile profile = Mockito.mock(DeviceProfile.class);
+        doAnswer(i -> {
+            ((Point) i.getArgument(0)).set(CELL_SIZE, CELL_SIZE);
+            return null;
+        }).when(profile).getCellSize(any(Point.class));
+        Mockito.when(profile.getCellSize()).thenReturn(new Point(CELL_SIZE, CELL_SIZE));
+        Mockito.when(profile.shouldInsetWidgets()).thenReturn(true);
+
+        InvariantDeviceProfile idp = new InvariantDeviceProfile();
+        List<DeviceProfile> supportedProfiles = new ArrayList<>(idp.supportedProfiles);
+        supportedProfiles.add(profile);
+        idp.supportedProfiles = Collections.unmodifiableList(supportedProfiles);
+        idp.numColumns = NUM_OF_COLS;
+        idp.numRows = NUM_OF_ROWS;
+        return idp;
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/WidgetsDiffReporterTest.java b/tests/src/com/android/launcher3/widget/picker/WidgetsDiffReporterTest.java
new file mode 100644
index 0000000..6232938
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/WidgetsDiffReporterTest.java
@@ -0,0 +1,311 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.android.launcher3.util.WidgetUtils.createAppWidgetProviderInfo;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.os.UserHandle;
+
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+import com.android.launcher3.widget.picker.WidgetsListAdapter.WidgetListBaseRowEntryComparator;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsDiffReporterTest {
+    private static final String TEST_PACKAGE_PREFIX = "com.android.test";
+    private static final WidgetListBaseRowEntryComparator COMPARATOR =
+            new WidgetListBaseRowEntryComparator();
+
+    @Mock private IconCache mIconCache;
+    @Mock private RecyclerView.Adapter mAdapter;
+
+    private InvariantDeviceProfile mTestProfile;
+    private WidgetsDiffReporter mWidgetsDiffReporter;
+    private Context mContext;
+    private WidgetsListHeaderEntry mHeaderA;
+    private WidgetsListHeaderEntry mHeaderB;
+    private WidgetsListHeaderEntry mHeaderC;
+    private WidgetsListHeaderEntry mHeaderD;
+    private WidgetsListHeaderEntry mHeaderE;
+    private WidgetsListContentEntry mContentC;
+    private WidgetsListContentEntry mContentE;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+
+        doAnswer(invocation -> ((ComponentWithLabel) invocation.getArgument(0))
+                .getComponent().getPackageName())
+                .when(mIconCache).getTitleNoCache(any());
+
+        mContext = getApplicationContext();
+        mWidgetsDiffReporter = new WidgetsDiffReporter(mIconCache, mAdapter);
+        mHeaderA = createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "A",
+                /* appName= */ "A", /* numOfWidgets= */ 3);
+        mHeaderB = createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "B",
+                /* appName= */ "B", /* numOfWidgets= */ 3);
+        mHeaderC = createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "C",
+                /* appName= */ "C", /* numOfWidgets= */ 3);
+        mContentC = createWidgetsContentEntry(TEST_PACKAGE_PREFIX + "C",
+                /* appName= */ "C", /* numOfWidgets= */ 3);
+        mHeaderD = createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "D",
+                /* appName= */ "D", /* numOfWidgets= */ 3);
+        mHeaderE = createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "E",
+                /* appName= */ "E", /* numOfWidgets= */ 3);
+        mContentE = createWidgetsContentEntry(TEST_PACKAGE_PREFIX + "E",
+                /* appName= */ "E", /* numOfWidgets= */ 3);
+    }
+
+    @Test
+    public void listNotChanged_shouldNotInvokeAnyCallbacks() {
+        // GIVEN the current list has app headers [A, B, C].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mHeaderC));
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, currentList, COMPARATOR);
+
+        // THEN there is no adaptor callback.
+        verifyZeroInteractions(mAdapter);
+        // THEN the current list contains the same entries.
+        assertThat(currentList).containsExactly(mHeaderA, mHeaderB, mHeaderC);
+    }
+
+    @Test
+    public void headersOnly_emptyListToNonEmpty_shouldInvokeNotifyDataSetChanged() {
+        // GIVEN the current list has app headers [A, B, C].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>();
+
+        List<WidgetsListBaseEntry> newList = List.of(
+                createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "A", "A", 3),
+                createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "B", "B", 3),
+                createWidgetsHeaderEntry(TEST_PACKAGE_PREFIX + "C", "C", 3));
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN notifyDataSetChanged is called
+        verify(mAdapter).notifyDataSetChanged();
+        // THEN the current list contains all elements from the new list.
+        assertThat(currentList).containsExactlyElementsIn(newList);
+    }
+
+    @Test
+    public void headersOnly_nonEmptyToEmptyList_shouldInvokeNotifyDataSetChanged() {
+        // GIVEN the current list has app headers [A, B, C].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mHeaderC));
+        // GIVEN the new list is empty.
+        List<WidgetsListBaseEntry> newList = List.of();
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN notifyDataSetChanged is called.
+        verify(mAdapter).notifyDataSetChanged();
+        // THEN the current list isEmpty.
+        assertThat(currentList).isEmpty();
+    }
+
+    @Test
+    public void headersOnly_itemAddedAndRemovedInTheNewList_shouldInvokeCorrectCallbacks() {
+        // GIVEN the current list has app headers [A, B, D].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mHeaderD));
+        // GIVEN the new list has app headers [A, C, E].
+        List<WidgetsListBaseEntry> newList = List.of(mHeaderA, mHeaderC, mHeaderE);
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN "B" is removed from position 1.
+        verify(mAdapter).notifyItemRemoved(/* position= */ 1);
+        // THEN "D" is removed from position 2.
+        verify(mAdapter).notifyItemRemoved(/* position= */ 2);
+        // THEN "C" is inserted at position 1.
+        verify(mAdapter).notifyItemInserted(/* position= */ 1);
+        // THEN "E" is inserted at position 2.
+        verify(mAdapter).notifyItemInserted(/* position= */ 2);
+        // THEN the current list contains all elements from the new list.
+        assertThat(currentList).containsExactlyElementsIn(newList);
+    }
+
+    @Test
+    public void headersContentsMix_itemAddedAndRemovedInTheNewList_shouldInvokeCorrectCallbacks() {
+        // GIVEN the current list has app headers [A, B, E content].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mContentE));
+        // GIVEN the new list has app headers [A, C content, D].
+        List<WidgetsListBaseEntry> newList = List.of(mHeaderA, mContentC, mHeaderD);
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN "B" is removed from position 1.
+        verify(mAdapter).notifyItemRemoved(/* position= */ 1);
+        // THEN "C content" is inserted at position 1.
+        verify(mAdapter).notifyItemInserted(/* position= */ 1);
+        // THEN "D" is inserted at position 2.
+        verify(mAdapter).notifyItemInserted(/* position= */ 2);
+        // THEN "E content" is removed from position 3.
+        verify(mAdapter).notifyItemRemoved(/* position= */ 3);
+        // THEN the current list contains all elements from the new list.
+        assertThat(currentList).containsExactlyElementsIn(newList);
+    }
+
+    @Test
+    public void headersContentsMix_userInteractWithHeader_shouldInvokeCorrectCallbacks() {
+        // GIVEN the current list has app headers [A, B, E content].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mContentE));
+        // GIVEN the new list has app headers [A, B, E content] and the user has interacted with B.
+        List<WidgetsListBaseEntry> newList =
+                List.of(mHeaderA, mHeaderB.withWidgetListShown(), mContentE);
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN notify "B" has been changed.
+        verify(mAdapter).notifyItemChanged(/* position= */ 1);
+        // THEN the current list contains all elements from the new list.
+        assertThat(currentList).containsExactlyElementsIn(newList);
+    }
+
+    @Test
+    public void headersContentsMix_headerWidgetsModified_shouldInvokeCorrectCallbacks() {
+        // GIVEN the current list has app headers [A, B, E content].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mContentE));
+        // GIVEN the new list has one of the headers widgets list modified.
+        List<WidgetsListBaseEntry> newList = List.of(
+                new WidgetsListHeaderEntry(
+                        mHeaderA.mPkgItem, mHeaderA.mTitleSectionName,
+                        mHeaderA.mWidgets.subList(0, 1)),
+                mHeaderB, mContentE);
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN notify "A" has been changed.
+        verify(mAdapter).notifyItemChanged(/* position= */ 0);
+        // THEN the current list contains all elements from the new list.
+        assertThat(currentList).containsExactlyElementsIn(newList);
+    }
+
+    @Test
+    public void headersContentsMix_contentMaxSpanSizeModified_shouldInvokeCorrectCallbacks() {
+        // GIVEN the current list has app headers [A, B, E content].
+        ArrayList<WidgetsListBaseEntry> currentList = new ArrayList<>(
+                List.of(mHeaderA, mHeaderB, mContentE));
+        // GIVEN the new list has max span size in "E content" modified.
+        List<WidgetsListBaseEntry> newList = List.of(
+                mHeaderA,
+                mHeaderB,
+                new WidgetsListContentEntry(
+                        mContentE.mPkgItem,
+                        mContentE.mTitleSectionName,
+                        mContentE.mWidgets,
+                        mContentE.getMaxSpanSizeInCells() + 1));
+
+        // WHEN computing the list difference.
+        mWidgetsDiffReporter.process(currentList, newList, COMPARATOR);
+
+        // THEN notify "E content" has been changed.
+        verify(mAdapter).notifyItemChanged(/* position= */ 2);
+        // THEN the current list contains all elements from the new list.
+        assertThat(currentList).containsExactlyElementsIn(newList);
+    }
+
+
+    private WidgetsListHeaderEntry createWidgetsHeaderEntry(String packageName, String appName,
+            int numOfWidgets) {
+        List<WidgetItem> widgetItems = generateWidgetItems(packageName, numOfWidgets);
+        PackageItemInfo pInfo = createPackageItemInfo(packageName, appName,
+                widgetItems.get(0).user);
+
+        return new WidgetsListHeaderEntry(pInfo, /* titleSectionName= */ "", widgetItems);
+    }
+
+    private WidgetsListContentEntry createWidgetsContentEntry(String packageName, String appName,
+            int numOfWidgets) {
+        List<WidgetItem> widgetItems = generateWidgetItems(packageName, numOfWidgets);
+        PackageItemInfo pInfo = createPackageItemInfo(packageName, appName,
+                widgetItems.get(0).user);
+
+        return new WidgetsListContentEntry(pInfo, /* titleSectionName= */ "", widgetItems);
+    }
+
+    private PackageItemInfo createPackageItemInfo(String packageName, String appName,
+            UserHandle userHandle) {
+        PackageItemInfo pInfo = new PackageItemInfo(packageName);
+        pInfo.title = appName;
+        pInfo.user = userHandle;
+        pInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+        return pInfo;
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = createAppWidgetProviderInfo(cn);
+
+            WidgetItem widgetItem = new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache);
+            widgetItems.add(widgetItem);
+        }
+        return widgetItems;
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/WidgetsListAdapterTest.java b/tests/src/com/android/launcher3/widget/picker/WidgetsListAdapterTest.java
new file mode 100644
index 0000000..44d6964
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/WidgetsListAdapterTest.java
@@ -0,0 +1,284 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Matchers.isNull;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.verify;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.os.Process;
+import android.os.UserHandle;
+import android.view.LayoutInflater;
+
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.util.ActivityContextWrapper;
+import com.android.launcher3.util.PackageUserKey;
+import com.android.launcher3.util.WidgetUtils;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Unit tests for WidgetsListAdapter
+ * Note that all indices matching are shifted by 1 to account for the empty space at the start.
+ */
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsListAdapterTest {
+    private static final String TEST_PACKAGE_PLACEHOLDER = "com.google.test";
+
+    @Mock private LayoutInflater mMockLayoutInflater;
+    @Mock private RecyclerView.AdapterDataObserver mListener;
+    @Mock private IconCache mIconCache;
+
+    private WidgetsListAdapter mAdapter;
+    private InvariantDeviceProfile mTestProfile;
+    private UserHandle mUserHandle;
+    private Context mContext;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        mContext = new ActivityContextWrapper(getApplicationContext());
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+        mUserHandle = Process.myUserHandle();
+        mAdapter = new WidgetsListAdapter(mContext, mMockLayoutInflater,
+                mIconCache, () -> 0, null, null);
+        mAdapter.registerAdapterDataObserver(mListener);
+
+        doAnswer(invocation -> ((ComponentWithLabel) invocation.getArgument(0))
+                        .getComponent().getPackageName())
+                .when(mIconCache).getTitleNoCache(any());
+    }
+
+    @Test
+    public void setWidgets_shouldNotifyDataSetChanged() {
+        mAdapter.setWidgets(generateSampleMap(1));
+
+        verify(mListener).onChanged();
+    }
+
+    @Test
+    public void setWidgets_withItemInserted_shouldNotifyItemInserted() {
+        mAdapter.setWidgets(generateSampleMap(1));
+        mAdapter.setWidgets(generateSampleMap(2));
+
+        verify(mListener).onItemRangeInserted(eq(2), eq(1));
+    }
+
+    @Test
+    public void setWidgets_withItemRemoved_shouldNotifyItemRemoved() {
+        mAdapter.setWidgets(generateSampleMap(2));
+        mAdapter.setWidgets(generateSampleMap(1));
+
+        verify(mListener).onItemRangeRemoved(eq(2), eq(1));
+    }
+
+    @Test
+    public void setWidgets_appIconChanged_shouldNotifyItemChanged() {
+        mAdapter.setWidgets(generateSampleMap(1));
+        mAdapter.setWidgets(generateSampleMap(1));
+
+        verify(mListener).onItemRangeChanged(eq(1), eq(1), isNull());
+    }
+
+    @Test
+    public void headerClick_expanded_shouldNotifyItemChange() {
+        // GIVEN a list of widgets entries:
+        // [com.google.test0, com.google.test0 content,
+        //  com.google.test1, com.google.test1 content,
+        //  com.google.test2, com.google.test2 content]
+        // The visible widgets entries: [com.google.test0, com.google.test1, com.google.test2].
+        mAdapter.setWidgets(generateSampleMap(3));
+
+        // WHEN com.google.test.1 header is expanded.
+        mAdapter.onHeaderClicked(/* showWidgets= */ true,
+                new PackageUserKey(TEST_PACKAGE_PLACEHOLDER + 1, mUserHandle));
+
+        // THEN the visible entries list becomes:
+        // [com.google.test0, com.google.test1, com.google.test1 content, com.google.test2]
+        // com.google.test.1 content is inserted into position 2.
+        verify(mListener).onItemRangeInserted(eq(3), eq(1));
+    }
+
+    @Test
+    public void setWidgets_expandedApp_moreWidgets_shouldNotifyItemChangedWithWidgetItemInfoDiff() {
+        // GIVEN the adapter was first populated with com.google.test0 & com.google.test1. Each app
+        // has one widget.
+        ArrayList<WidgetsListBaseEntry> allEntries = generateSampleMap(2);
+        mAdapter.setWidgets(allEntries);
+        // GIVEN test com.google.test1 is expanded.
+        // Visible entries in the adapter are:
+        // [com.google.test0, com.google.test1, com.google.test1 content]
+        mAdapter.onHeaderClicked(/* showWidgets= */ true,
+                new PackageUserKey(TEST_PACKAGE_PLACEHOLDER + 1, mUserHandle));
+        Mockito.reset(mListener);
+
+        // WHEN the adapter is updated with the same list of apps but com.google.test1 has 2 widgets
+        // now.
+        WidgetsListContentEntry testPackage1ContentEntry =
+                (WidgetsListContentEntry) allEntries.get(3);
+        WidgetItem widgetItem = testPackage1ContentEntry.mWidgets.get(0);
+        WidgetsListContentEntry newTestPackage1ContentEntry = new WidgetsListContentEntry(
+                testPackage1ContentEntry.mPkgItem,
+                testPackage1ContentEntry.mTitleSectionName, List.of(widgetItem, widgetItem));
+        allEntries.set(3, newTestPackage1ContentEntry);
+        mAdapter.setWidgets(allEntries);
+
+        // THEN the onItemRangeChanged is invoked for "com.google.test1 content" at index 2.
+        verify(mListener).onItemRangeChanged(eq(3), eq(1), isNull());
+    }
+
+    @Test
+    public void setWidgets_hodgepodge_shouldInvokeExpectedDataObserverCallbacks() {
+        // GIVEN a widgets entry list:
+        // Index:  0|   1      | 2|      3   | 4|     5    | 6|     7    | 8|     9    |
+        //        [A, A content, B, B content, C, C content, D, D content, E, E content]
+        List<WidgetsListBaseEntry> allAppsWithWidgets = generateSampleMap(5);
+        // GIVEN the current widgets list consist of [A, A content, B, B content, E, E content].
+        // GIVEN the visible widgets list consist of [A, B, E]
+        List<WidgetsListBaseEntry> currentList = List.of(
+                // A & A content
+                allAppsWithWidgets.get(0), allAppsWithWidgets.get(1),
+                // B & B content
+                allAppsWithWidgets.get(2), allAppsWithWidgets.get(3),
+                // E & E content
+                allAppsWithWidgets.get(8), allAppsWithWidgets.get(9));
+        mAdapter.setWidgets(currentList);
+
+        // WHEN the widgets list is updated to [A, A content, C, C content, D, D content].
+        // WHEN the visible widgets list is updated to [A, C, D].
+        List<WidgetsListBaseEntry> newList = List.of(
+                // A & A content
+                allAppsWithWidgets.get(0), allAppsWithWidgets.get(1),
+                // C & C content
+                allAppsWithWidgets.get(4), allAppsWithWidgets.get(5),
+                // D & D content
+                allAppsWithWidgets.get(6), allAppsWithWidgets.get(7));
+        mAdapter.setWidgets(newList);
+
+        // Account for 1st items as empty space
+        // Computation logic                           | [Intermediate list during computation]
+        // THEN B <> C < 0, removed B from index 1     | [A, E]
+        verify(mListener).onItemRangeRemoved(/* positionStart= */ 2, /* itemCount= */ 1);
+        // THEN E <> C > 0, C inserted to index 1      | [A, C, E]
+        verify(mListener).onItemRangeInserted(/* positionStart= */ 2, /* itemCount= */ 1);
+        // THEN E <> D > 0, D inserted to index 2      | [A, C, D, E]
+        verify(mListener).onItemRangeInserted(/* positionStart= */ 3, /* itemCount= */ 1);
+        // THEN E <> null = -1, E deleted from index 3 | [A, C, D]
+        verify(mListener).onItemRangeRemoved(/* positionStart= */ 4, /* itemCount= */ 1);
+    }
+
+    @Test
+    public void setWidgetsOnSearch_expandedApp_shouldResetExpandedApp() {
+        // GIVEN a list of widgets entries:
+        // [com.google.test0, com.google.test0 content,
+        //  com.google.test1, com.google.test1 content,
+        //  com.google.test2, com.google.test2 content]
+        // The visible widgets entries: [com.google.test0, com.google.test1, com.google.test2].
+        ArrayList<WidgetsListBaseEntry> allEntries = generateSampleMap(2);
+        mAdapter.setWidgetsOnSearch(allEntries);
+        // GIVEN com.google.test.1 header is expanded. The visible entries list becomes:
+        // [com.google.test0, com.google.test1, com.google.test1 content, com.google.test2]
+        mAdapter.onHeaderClicked(/* showWidgets= */ true,
+                new PackageUserKey(TEST_PACKAGE_PLACEHOLDER + 1, mUserHandle));
+        Mockito.reset(mListener);
+
+        // WHEN same widget entries are set again.
+        mAdapter.setWidgetsOnSearch(allEntries);
+
+        // THEN expanded app is reset and the visible entries list becomes:
+        // [com.google.test0, com.google.test1, com.google.test2]
+        verify(mListener).onItemRangeChanged(eq(2), eq(1), isNull());
+        verify(mListener).onItemRangeRemoved(/* positionStart= */ 3, /* itemCount= */ 1);
+    }
+
+    /**
+     * Generates a list of sample widget entries.
+     *
+     * <p>Each sample app has 1 widget only. An app is represented by 2 entries,
+     * {@link WidgetsListHeaderEntry} & {@link WidgetsListContentEntry}. Only
+     * {@link WidgetsListHeaderEntry} is always visible in the {@link WidgetsListAdapter}.
+     * {@link WidgetsListContentEntry} is only shown upon clicking the corresponding app's
+     * {@link WidgetsListHeaderEntry}. Only at most one {@link WidgetsListContentEntry} is shown at
+     * a time.
+     *
+     * @param num the number of apps that have widgets.
+     */
+    private ArrayList<WidgetsListBaseEntry> generateSampleMap(int num) {
+        ArrayList<WidgetsListBaseEntry> result = new ArrayList<>();
+        if (num <= 0) return result;
+
+        for (int i = 0; i < num; i++) {
+            String packageName = TEST_PACKAGE_PLACEHOLDER + i;
+
+            List<WidgetItem> widgetItems = generateWidgetItems(packageName, /* numOfWidgets= */ 1);
+
+            PackageItemInfo pInfo = new PackageItemInfo(packageName);
+            pInfo.title = pInfo.packageName;
+            pInfo.user = widgetItems.get(0).user;
+            pInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+
+            result.add(new WidgetsListHeaderEntry(pInfo, /* titleSectionName= */ "", widgetItems));
+            result.add(new WidgetsListContentEntry(pInfo, /* titleSectionName= */ "", widgetItems));
+        }
+
+        return result;
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = WidgetUtils.createAppWidgetProviderInfo(cn);
+
+            widgetItems.add(new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache));
+        }
+        return widgetItems;
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/WidgetsListHeaderViewHolderBinderTest.java b/tests/src/com/android/launcher3/widget/picker/WidgetsListHeaderViewHolderBinderTest.java
new file mode 100644
index 0000000..969c12a
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/WidgetsListHeaderViewHolderBinderTest.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.verify;
+
+import static java.util.Collections.EMPTY_LIST;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.view.LayoutInflater;
+import android.widget.FrameLayout;
+import android.widget.TextView;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.R;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.util.ActivityContextWrapper;
+import com.android.launcher3.util.PackageUserKey;
+import com.android.launcher3.util.WidgetUtils;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsListHeaderViewHolderBinderTest {
+    private static final String TEST_PACKAGE = "com.google.test";
+    private static final String APP_NAME = "Test app";
+
+    private Context mContext;
+    private WidgetsListHeaderViewHolderBinder mViewHolderBinder;
+    private InvariantDeviceProfile mTestProfile;
+
+    @Mock
+    private IconCache mIconCache;
+    @Mock
+    private OnHeaderClickListener mOnHeaderClickListener;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = new ActivityContextWrapper(getApplicationContext());
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+
+        doAnswer(invocation -> {
+            ComponentWithLabel componentWithLabel = (ComponentWithLabel) invocation.getArgument(0);
+            return componentWithLabel.getComponent().getShortClassName();
+        }).when(mIconCache).getTitleNoCache(any());
+        mViewHolderBinder = new WidgetsListHeaderViewHolderBinder(
+                LayoutInflater.from(mContext),
+                mOnHeaderClickListener,
+                new WidgetsListDrawableFactory(mContext));
+    }
+
+    @Test
+    public void bindViewHolder_appWith3Widgets_shouldShowTheCorrectAppNameAndSubtitle() {
+        WidgetsListHeaderHolder viewHolder = mViewHolderBinder.newViewHolder(
+                new FrameLayout(mContext));
+        WidgetsListHeader widgetsListHeader = viewHolder.mWidgetsListHeader;
+        WidgetsListHeaderEntry entry = generateSampleAppHeader(
+                APP_NAME,
+                TEST_PACKAGE,
+                /* numOfWidgets= */ 3);
+        mViewHolderBinder.bindViewHolder(viewHolder, entry, /* position= */ 0, EMPTY_LIST);
+
+        TextView appTitle = widgetsListHeader.findViewById(R.id.app_title);
+        TextView appSubtitle = widgetsListHeader.findViewById(R.id.app_subtitle);
+        assertThat(appTitle.getText()).isEqualTo(APP_NAME);
+        assertThat(appSubtitle.getText()).isEqualTo("3 widgets");
+    }
+
+    @Test
+    public void bindViewHolder_shouldAttachOnHeaderClickListener() {
+        WidgetsListHeaderHolder viewHolder = mViewHolderBinder.newViewHolder(
+                new FrameLayout(mContext));
+        WidgetsListHeader widgetsListHeader = viewHolder.mWidgetsListHeader;
+        WidgetsListHeaderEntry entry = generateSampleAppHeader(
+                APP_NAME,
+                TEST_PACKAGE,
+                /* numOfWidgets= */ 3);
+
+        mViewHolderBinder.bindViewHolder(viewHolder, entry, /* position= */ 0, EMPTY_LIST);
+        widgetsListHeader.callOnClick();
+
+        verify(mOnHeaderClickListener).onHeaderClicked(eq(true),
+                eq(new PackageUserKey(entry.mPkgItem.packageName, entry.mPkgItem.user)));
+    }
+
+    private WidgetsListHeaderEntry generateSampleAppHeader(String appName, String packageName,
+            int numOfWidgets) {
+        PackageItemInfo appInfo = new PackageItemInfo(packageName);
+        appInfo.title = appName;
+        appInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+
+        return new WidgetsListHeaderEntry(appInfo,
+                /* titleSectionName= */ "",
+                generateWidgetItems(packageName, numOfWidgets));
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = WidgetUtils.createAppWidgetProviderInfo(cn);
+
+            widgetItems.add(new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache));
+        }
+        return widgetItems;
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/WidgetsListSearchHeaderViewHolderBinderTest.java b/tests/src/com/android/launcher3/widget/picker/WidgetsListSearchHeaderViewHolderBinderTest.java
new file mode 100644
index 0000000..453f4fb
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/WidgetsListSearchHeaderViewHolderBinderTest.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.verify;
+
+import static java.util.Collections.EMPTY_LIST;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.view.LayoutInflater;
+import android.widget.FrameLayout;
+import android.widget.TextView;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.R;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.util.ActivityContextWrapper;
+import com.android.launcher3.util.PackageUserKey;
+import com.android.launcher3.util.WidgetUtils;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListSearchHeaderEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsListSearchHeaderViewHolderBinderTest {
+    private static final String TEST_PACKAGE = "com.google.test";
+    private static final String APP_NAME = "Test app";
+
+    private Context mContext;
+    private WidgetsListSearchHeaderViewHolderBinder mViewHolderBinder;
+    private InvariantDeviceProfile mTestProfile;
+
+    @Mock
+    private IconCache mIconCache;
+    @Mock
+    private OnHeaderClickListener mOnHeaderClickListener;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = new ActivityContextWrapper(getApplicationContext());
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+
+        doAnswer(invocation -> {
+            ComponentWithLabel componentWithLabel = (ComponentWithLabel) invocation.getArgument(0);
+            return componentWithLabel.getComponent().getShortClassName();
+        }).when(mIconCache).getTitleNoCache(any());
+        mViewHolderBinder = new WidgetsListSearchHeaderViewHolderBinder(
+                LayoutInflater.from(mContext),
+                mOnHeaderClickListener,
+                new WidgetsListDrawableFactory(mContext));
+    }
+
+    @Test
+    public void bindViewHolder_appWith3Widgets_shouldShowTheCorrectAppNameAndSubtitle() {
+        WidgetsListSearchHeaderHolder viewHolder = mViewHolderBinder.newViewHolder(
+                new FrameLayout(mContext));
+        WidgetsListHeader widgetsListHeader = viewHolder.mWidgetsListHeader;
+        WidgetsListSearchHeaderEntry entry = generateSampleSearchHeader(
+                APP_NAME,
+                TEST_PACKAGE,
+                /* numOfWidgets= */ 3);
+        mViewHolderBinder.bindViewHolder(viewHolder, entry, /* position= */ 0, EMPTY_LIST);
+
+        TextView appTitle = widgetsListHeader.findViewById(R.id.app_title);
+        TextView appSubtitle = widgetsListHeader.findViewById(R.id.app_subtitle);
+        assertThat(appTitle.getText()).isEqualTo(APP_NAME);
+        assertThat(appSubtitle.getText())
+                .isEqualTo(".SampleWidget0, .SampleWidget1, .SampleWidget2");
+    }
+
+    @Test
+    public void bindViewHolder_shouldAttachOnHeaderClickListener() {
+        WidgetsListSearchHeaderHolder viewHolder = mViewHolderBinder.newViewHolder(
+                new FrameLayout(mContext));
+        WidgetsListHeader widgetsListHeader = viewHolder.mWidgetsListHeader;
+        WidgetsListSearchHeaderEntry entry = generateSampleSearchHeader(
+                APP_NAME,
+                TEST_PACKAGE,
+                /* numOfWidgets= */ 3);
+
+        mViewHolderBinder.bindViewHolder(viewHolder, entry, /* position= */ 0, EMPTY_LIST);
+        widgetsListHeader.callOnClick();
+
+        verify(mOnHeaderClickListener).onHeaderClicked(eq(true),
+                eq(new PackageUserKey(entry.mPkgItem.packageName, entry.mPkgItem.user)));
+    }
+
+    private WidgetsListSearchHeaderEntry generateSampleSearchHeader(String appName,
+            String packageName, int numOfWidgets) {
+        PackageItemInfo appInfo = new PackageItemInfo(packageName);
+        appInfo.title = appName;
+        appInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+
+        return new WidgetsListSearchHeaderEntry(appInfo,
+                /* titleSectionName= */ "",
+                generateWidgetItems(packageName, numOfWidgets));
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = WidgetUtils.createAppWidgetProviderInfo(cn);
+
+            widgetItems.add(new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache));
+        }
+        return widgetItems;
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/WidgetsListTableViewHolderBinderTest.java b/tests/src/com/android/launcher3/widget/picker/WidgetsListTableViewHolderBinderTest.java
new file mode 100644
index 0000000..5816b77
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/WidgetsListTableViewHolderBinderTest.java
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+
+import static java.util.Collections.EMPTY_LIST;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.View.OnLongClickListener;
+import android.widget.FrameLayout;
+import android.widget.TableRow;
+import android.widget.TextView;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.R;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.util.ActivityContextWrapper;
+import com.android.launcher3.util.Executors;
+import com.android.launcher3.util.WidgetUtils;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.WidgetCell;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsListTableViewHolderBinderTest {
+    private static final String TEST_PACKAGE = "com.google.test";
+    private static final String APP_NAME = "Test app";
+
+    private Context mContext;
+    private WidgetsListTableViewHolderBinder mViewHolderBinder;
+    private InvariantDeviceProfile mTestProfile;
+
+    @Mock
+    private OnLongClickListener mOnLongClickListener;
+    @Mock
+    private OnClickListener mOnIconClickListener;
+    @Mock
+    private IconCache mIconCache;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = new ActivityContextWrapper(getApplicationContext());
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+
+        doAnswer(invocation -> {
+            ComponentWithLabel componentWithLabel = (ComponentWithLabel) invocation.getArgument(0);
+            return componentWithLabel.getComponent().getShortClassName();
+        }).when(mIconCache).getTitleNoCache(any());
+
+        mViewHolderBinder = new WidgetsListTableViewHolderBinder(
+                LayoutInflater.from(mContext),
+                mOnIconClickListener,
+                mOnLongClickListener,
+                new WidgetsListDrawableFactory(mContext));
+    }
+
+    @Test
+    public void bindViewHolder_appWith3Widgets_shouldHave3Widgets() throws Exception {
+        WidgetsRowViewHolder viewHolder = mViewHolderBinder.newViewHolder(
+                new FrameLayout(mContext));
+        WidgetsListContentEntry entry = generateSampleAppWithWidgets(
+                APP_NAME,
+                TEST_PACKAGE,
+                /* numOfWidgets= */ 3);
+        mViewHolderBinder.bindViewHolder(viewHolder, entry, /* position= */ 0, EMPTY_LIST);
+        Executors.MAIN_EXECUTOR.submit(() -> { }).get();
+
+        // THEN the table container has one row, which contains 3 widgets.
+        // View:  .SampleWidget0 | .SampleWidget1 | .SampleWidget2
+        assertThat(viewHolder.tableContainer.getChildCount()).isEqualTo(1);
+        TableRow row = (TableRow) viewHolder.tableContainer.getChildAt(0);
+        assertThat(row.getChildCount()).isEqualTo(3);
+        // Widget 0 label is .SampleWidget0.
+        assertWidgetCellWithLabel(row.getChildAt(0), ".SampleWidget0");
+        // Widget 1 label is .SampleWidget1.
+        assertWidgetCellWithLabel(row.getChildAt(1), ".SampleWidget1");
+        // Widget 2 label is .SampleWidget2.
+        assertWidgetCellWithLabel(row.getChildAt(2), ".SampleWidget2");
+    }
+
+    private WidgetsListContentEntry generateSampleAppWithWidgets(String appName, String packageName,
+            int numOfWidgets) {
+        PackageItemInfo appInfo = new PackageItemInfo(packageName);
+        appInfo.title = appName;
+        appInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+
+        return new WidgetsListContentEntry(appInfo,
+                /* titleSectionName= */ "",
+                generateWidgetItems(packageName, numOfWidgets),
+                Integer.MAX_VALUE);
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = WidgetUtils.createAppWidgetProviderInfo(cn);
+
+            widgetItems.add(new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache));
+        }
+        return widgetItems;
+    }
+
+    private void assertWidgetCellWithLabel(View view, String label) {
+        assertThat(view).isInstanceOf(WidgetCell.class);
+        TextView widgetLabel = (TextView) view.findViewById(R.id.widget_name);
+        assertThat(widgetLabel.getText()).isEqualTo(label);
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/model/WidgetsListContentEntryTest.java b/tests/src/com/android/launcher3/widget/picker/model/WidgetsListContentEntryTest.java
new file mode 100644
index 0000000..4b61b2c
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/model/WidgetsListContentEntryTest.java
@@ -0,0 +1,257 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker.model;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.android.launcher3.util.WidgetUtils.createAppWidgetProviderInfo;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsListContentEntryTest {
+    private static final String PACKAGE_NAME = "com.android.test";
+    private static final String PACKAGE_NAME_2 = "com.android.test2";
+    private final PackageItemInfo mPackageItemInfo1 = new PackageItemInfo(PACKAGE_NAME);
+    private final PackageItemInfo mPackageItemInfo2 = new PackageItemInfo(PACKAGE_NAME_2);
+    private final ComponentName mWidget1 = ComponentName.createRelative(PACKAGE_NAME, ".mWidget1");
+    private final ComponentName mWidget2 = ComponentName.createRelative(PACKAGE_NAME, ".mWidget2");
+    private final ComponentName mWidget3 = ComponentName.createRelative(PACKAGE_NAME, ".mWidget3");
+    private final Map<ComponentName, String> mWidgetsToLabels = new HashMap();
+
+    @Mock private IconCache mIconCache;
+
+    private InvariantDeviceProfile mTestProfile;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mWidgetsToLabels.put(mWidget1, "Cat");
+        mWidgetsToLabels.put(mWidget2, "Dog");
+        mWidgetsToLabels.put(mWidget3, "Bird");
+
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+
+        doAnswer(invocation -> {
+            ComponentWithLabel componentWithLabel = (ComponentWithLabel) invocation.getArgument(0);
+            return mWidgetsToLabels.get(componentWithLabel.getComponent());
+        }).when(mIconCache).getTitleNoCache(any());
+    }
+
+    @Test
+    public void unsortedWidgets_diffLabels_shouldSortWidgetItems() {
+        // GIVEN a list of widgets in unsorted order.
+        // Cat 2x3
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 3);
+        // Dog 2x3
+        WidgetItem widgetItem2 = createWidgetItem(mWidget2, /* spanX= */ 2, /* spanY= */ 3);
+        // Bird 2x3
+        WidgetItem widgetItem3 = createWidgetItem(mWidget3, /* spanX= */ 2, /* spanY= */ 3);
+
+        // WHEN creates a WidgetsListRowEntry with the unsorted widgets.
+        WidgetsListContentEntry widgetsListRowEntry = new WidgetsListContentEntry(mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1, widgetItem2, widgetItem3));
+
+        // THEN the widgets list is sorted by their labels alphabetically: [Bird, Cat, Dog].
+        assertThat(widgetsListRowEntry.mWidgets)
+                .containsExactly(widgetItem3, widgetItem1, widgetItem2)
+                .inOrder();
+        assertThat(widgetsListRowEntry.mTitleSectionName).isEqualTo("T");
+        assertThat(widgetsListRowEntry.mPkgItem).isEqualTo(mPackageItemInfo1);
+    }
+
+    @Test
+    public void unsortedWidgets_sameLabels_differentSize_shouldSortWidgetItems() {
+        // GIVEN a list of widgets in unsorted order.
+        // Cat 3x3
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 3, /* spanY= */ 3);
+        // Cat 1x2
+        WidgetItem widgetItem2 = createWidgetItem(mWidget1, /* spanX= */ 1, /* spanY= */ 2);
+        // Cat 2x2
+        WidgetItem widgetItem3 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 2);
+
+        // WHEN creates a WidgetsListRowEntry with the unsorted widgets.
+        WidgetsListContentEntry widgetsListRowEntry = new WidgetsListContentEntry(mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1, widgetItem2, widgetItem3));
+
+        // THEN the widgets list is sorted by their gird sizes in an ascending order:
+        // [1x2, 2x2, 3x3].
+        assertThat(widgetsListRowEntry.mWidgets)
+                .containsExactly(widgetItem2, widgetItem3, widgetItem1)
+                .inOrder();
+        assertThat(widgetsListRowEntry.mTitleSectionName).isEqualTo("T");
+        assertThat(widgetsListRowEntry.mPkgItem).isEqualTo(mPackageItemInfo1);
+    }
+
+    @Test
+    public void unsortedWidgets_hodgepodge_shouldSortWidgetItems() {
+        // GIVEN a list of widgets in unsorted order.
+        // Cat 3x3
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 3, /* spanY= */ 3);
+        // Cat 1x2
+        WidgetItem widgetItem2 = createWidgetItem(mWidget1, /* spanX= */ 1, /* spanY= */ 2);
+        // Dog 2x2
+        WidgetItem widgetItem3 = createWidgetItem(mWidget2, /* spanX= */ 2, /* spanY= */ 2);
+        // Bird 2x2
+        WidgetItem widgetItem4 = createWidgetItem(mWidget3, /* spanX= */ 2, /* spanY= */ 2);
+
+        // WHEN creates a WidgetsListRowEntry with the unsorted widgets.
+        WidgetsListContentEntry widgetsListRowEntry = new WidgetsListContentEntry(mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1, widgetItem2, widgetItem3, widgetItem4));
+
+        // THEN the widgets list is first sorted by labels alphabetically. Then, for widgets with
+        // same labels, they are sorted by their gird sizes in an ascending order:
+        // [Bird 2x2, Cat 1x2, Cat 3x3, Dog 2x2]
+        assertThat(widgetsListRowEntry.mWidgets)
+                .containsExactly(widgetItem4, widgetItem2, widgetItem1, widgetItem3)
+                .inOrder();
+        assertThat(widgetsListRowEntry.mTitleSectionName).isEqualTo("T");
+        assertThat(widgetsListRowEntry.mPkgItem).isEqualTo(mPackageItemInfo1);
+    }
+
+    @Test
+    public void equals_entriesWithDifferentPackageItemInfo_returnFalse() {
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry1 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry2 = new WidgetsListContentEntry(
+                mPackageItemInfo2,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+
+        assertThat(widgetsListRowEntry1.equals(widgetsListRowEntry2)).isFalse();
+    }
+
+    @Test
+    public void equals_entriesWithDifferentTitleSectionName_returnFalse() {
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry1 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry2 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "S",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+
+        assertThat(widgetsListRowEntry1.equals(widgetsListRowEntry2)).isFalse();
+    }
+
+    @Test
+    public void equals_entriesWithDifferentWidgetsList_returnFalse() {
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 3);
+        WidgetItem widgetItem2 = createWidgetItem(mWidget2, /* spanX= */ 2, /* spanY= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry1 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry2 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem2),
+                /* maxSpanSizeInCells= */ 3);
+
+        assertThat(widgetsListRowEntry1.equals(widgetsListRowEntry2)).isFalse();
+    }
+
+    @Test
+    public void equals_entriesWithDifferentMaxSpanSize_returnFalse() {
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry1 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry2 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 2);
+
+        assertThat(widgetsListRowEntry1.equals(widgetsListRowEntry2)).isFalse();
+    }
+
+    @Test
+    public void equals_entriesWithSameContents_returnTrue() {
+        WidgetItem widgetItem1 = createWidgetItem(mWidget1, /* spanX= */ 2, /* spanY= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry1 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+        WidgetsListContentEntry widgetsListRowEntry2 = new WidgetsListContentEntry(
+                mPackageItemInfo1,
+                /* titleSectionName= */ "T",
+                List.of(widgetItem1),
+                /* maxSpanSizeInCells= */ 3);
+
+        assertThat(widgetsListRowEntry1.equals(widgetsListRowEntry2)).isTrue();
+    }
+
+    private WidgetItem createWidgetItem(ComponentName componentName, int spanX, int spanY) {
+        String label = mWidgetsToLabels.get(componentName);
+        AppWidgetProviderInfo widgetInfo = createAppWidgetProviderInfo(componentName);
+
+        LauncherAppWidgetProviderInfo launcherAppWidgetProviderInfo =
+                LauncherAppWidgetProviderInfo.fromProviderInfo(getApplicationContext(), widgetInfo);
+        launcherAppWidgetProviderInfo.spanX = spanX;
+        launcherAppWidgetProviderInfo.spanY = spanY;
+        launcherAppWidgetProviderInfo.label = label;
+
+        return new WidgetItem(launcherAppWidgetProviderInfo, mTestProfile, mIconCache);
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithmTest.java b/tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithmTest.java
new file mode 100644
index 0000000..c862d6b
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/search/SimpleWidgetsSearchAlgorithmTest.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.widget.picker.search;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
+import static com.android.launcher3.util.WidgetUtils.createAppWidgetProviderInfo;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.ArgumentMatchers.matches;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.verify;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.os.UserHandle;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.icons.BitmapInfo;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.model.data.PackageItemInfo;
+import com.android.launcher3.popup.PopupDataProvider;
+import com.android.launcher3.search.SearchCallback;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+import com.android.launcher3.widget.model.WidgetsListContentEntry;
+import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
+import com.android.launcher3.widget.model.WidgetsListSearchHeaderEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class SimpleWidgetsSearchAlgorithmTest {
+
+    @Mock private IconCache mIconCache;
+
+    private InvariantDeviceProfile mTestProfile;
+    private WidgetsListHeaderEntry mCalendarHeaderEntry;
+    private WidgetsListContentEntry mCalendarContentEntry;
+    private WidgetsListHeaderEntry mCameraHeaderEntry;
+    private WidgetsListContentEntry mCameraContentEntry;
+    private WidgetsListHeaderEntry mClockHeaderEntry;
+    private WidgetsListContentEntry mClockContentEntry;
+    private Context mContext;
+
+    private SimpleWidgetsSearchAlgorithm mSimpleWidgetsSearchAlgorithm;
+    @Mock
+    private PopupDataProvider mDataProvider;
+    @Mock
+    private SearchCallback<WidgetsListBaseEntry> mSearchCallback;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        doAnswer(invocation -> {
+            ComponentWithLabel componentWithLabel = (ComponentWithLabel) invocation.getArgument(0);
+            return componentWithLabel.getComponent().getShortClassName();
+        }).when(mIconCache).getTitleNoCache(any());
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+        mContext = getApplicationContext();
+
+        mCalendarHeaderEntry =
+                createWidgetsHeaderEntry("com.example.android.Calendar", "Calendar", 2);
+        mCalendarContentEntry =
+                createWidgetsContentEntry("com.example.android.Calendar", "Calendar", 2);
+        mCameraHeaderEntry = createWidgetsHeaderEntry("com.example.android.Camera", "Camera", 11);
+        mCameraContentEntry = createWidgetsContentEntry("com.example.android.Camera", "Camera", 11);
+        mClockHeaderEntry = createWidgetsHeaderEntry("com.example.android.Clock", "Clock", 3);
+        mClockContentEntry = createWidgetsContentEntry("com.example.android.Clock", "Clock", 3);
+
+        mSimpleWidgetsSearchAlgorithm = MAIN_EXECUTOR.submit(
+                () -> new SimpleWidgetsSearchAlgorithm(mDataProvider)).get();
+        doReturn(Collections.EMPTY_LIST).when(mDataProvider).getAllWidgets();
+    }
+
+    @Test
+    public void filter_shouldMatchOnAppName() {
+        doReturn(List.of(mCalendarHeaderEntry, mCalendarContentEntry, mCameraHeaderEntry,
+                mCameraContentEntry, mClockHeaderEntry, mClockContentEntry))
+                .when(mDataProvider)
+                .getAllWidgets();
+
+        assertEquals(List.of(
+                new WidgetsListSearchHeaderEntry(
+                        mCalendarHeaderEntry.mPkgItem,
+                        mCalendarHeaderEntry.mTitleSectionName,
+                        mCalendarHeaderEntry.mWidgets),
+                mCalendarContentEntry,
+                new WidgetsListSearchHeaderEntry(
+                        mCameraHeaderEntry.mPkgItem,
+                        mCameraHeaderEntry.mTitleSectionName,
+                        mCameraHeaderEntry.mWidgets),
+                mCameraContentEntry),
+                SimpleWidgetsSearchAlgorithm.getFilteredWidgets(mDataProvider, "Ca"));
+    }
+
+    @Test
+    public void filter_shouldMatchOnWidgetLabel() {
+        doReturn(List.of(mCalendarHeaderEntry, mCalendarContentEntry, mCameraHeaderEntry,
+                mCameraContentEntry))
+                .when(mDataProvider)
+                .getAllWidgets();
+
+        assertEquals(List.of(
+                new WidgetsListSearchHeaderEntry(
+                        mCalendarHeaderEntry.mPkgItem,
+                        mCalendarHeaderEntry.mTitleSectionName,
+                        mCalendarHeaderEntry.mWidgets.subList(1, 2)),
+                new WidgetsListContentEntry(
+                        mCalendarHeaderEntry.mPkgItem,
+                        mCalendarHeaderEntry.mTitleSectionName,
+                        mCalendarHeaderEntry.mWidgets.subList(1, 2)),
+                new WidgetsListSearchHeaderEntry(
+                        mCameraHeaderEntry.mPkgItem,
+                        mCameraHeaderEntry.mTitleSectionName,
+                        mCameraHeaderEntry.mWidgets.subList(1, 3)),
+                new WidgetsListContentEntry(
+                        mCameraHeaderEntry.mPkgItem,
+                        mCameraHeaderEntry.mTitleSectionName,
+                        mCameraHeaderEntry.mWidgets.subList(1, 3))),
+                SimpleWidgetsSearchAlgorithm.getFilteredWidgets(mDataProvider, "Widget1"));
+    }
+
+    @Test
+    public void doSearch_shouldInformCallback() throws Exception {
+        doReturn(List.of(mCalendarHeaderEntry, mCalendarContentEntry, mCameraHeaderEntry,
+                mCameraContentEntry, mClockHeaderEntry, mClockContentEntry))
+                .when(mDataProvider)
+                .getAllWidgets();
+        mSimpleWidgetsSearchAlgorithm.doSearch("Ca", mSearchCallback);
+        MAIN_EXECUTOR.submit(() -> { }).get();
+        verify(mSearchCallback).onSearchResult(
+                matches("Ca"), argThat(a -> a != null && !a.isEmpty()));
+    }
+
+    private WidgetsListHeaderEntry createWidgetsHeaderEntry(String packageName, String appName,
+            int numOfWidgets) {
+        List<WidgetItem> widgetItems = generateWidgetItems(packageName, numOfWidgets);
+        PackageItemInfo pInfo = createPackageItemInfo(packageName, appName,
+                widgetItems.get(0).user);
+
+        return new WidgetsListHeaderEntry(pInfo, /* titleSectionName= */ "", widgetItems);
+    }
+
+    private WidgetsListContentEntry createWidgetsContentEntry(String packageName, String appName,
+            int numOfWidgets) {
+        List<WidgetItem> widgetItems = generateWidgetItems(packageName, numOfWidgets);
+        PackageItemInfo pInfo = createPackageItemInfo(packageName, appName,
+                widgetItems.get(0).user);
+
+        return new WidgetsListContentEntry(pInfo, /* titleSectionName= */ "", widgetItems);
+    }
+
+    private PackageItemInfo createPackageItemInfo(String packageName, String appName,
+            UserHandle userHandle) {
+        PackageItemInfo pInfo = new PackageItemInfo(packageName);
+        pInfo.title = appName;
+        pInfo.user = userHandle;
+        pInfo.bitmap = BitmapInfo.of(Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8), 0);
+        return pInfo;
+    }
+
+    private List<WidgetItem> generateWidgetItems(String packageName, int numOfWidgets) {
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        for (int i = 0; i < numOfWidgets; i++) {
+            ComponentName cn = ComponentName.createRelative(packageName, ".SampleWidget" + i);
+            AppWidgetProviderInfo widgetInfo = createAppWidgetProviderInfo(cn);
+
+            WidgetItem widgetItem = new WidgetItem(
+                    LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, widgetInfo),
+                    mTestProfile, mIconCache);
+            widgetItems.add(widgetItem);
+        }
+        return widgetItems;
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarControllerTest.java b/tests/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarControllerTest.java
new file mode 100644
index 0000000..583d37f
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/search/WidgetsSearchBarControllerTest.java
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.widget.picker.search;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+import android.content.Context;
+import android.view.View;
+import android.widget.ImageButton;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.ExtendedEditText;
+import com.android.launcher3.search.SearchAlgorithm;
+import com.android.launcher3.widget.model.WidgetsListBaseEntry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class WidgetsSearchBarControllerTest {
+
+    private WidgetsSearchBarController mController;
+    private ExtendedEditText mEditText;
+    private ImageButton mCancelButton;
+    @Mock
+    private SearchModeListener mSearchModeListener;
+    @Mock
+    private SearchAlgorithm<WidgetsListBaseEntry> mSearchAlgorithm;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        Context context = getApplicationContext();
+
+        mEditText = new ExtendedEditText(context);
+        mCancelButton = new ImageButton(context);
+        mController = new WidgetsSearchBarController(
+                mSearchAlgorithm, mEditText, mCancelButton, mSearchModeListener);
+    }
+
+    @Test
+    public void onSearchResult_shouldInformSearchModeListener() {
+        ArrayList<WidgetsListBaseEntry> entries = new ArrayList<>();
+        mController.onSearchResult("abc", entries);
+
+        verify(mSearchModeListener).onSearchResults(entries);
+    }
+
+    @Test
+    public void afterTextChanged_shouldInformSearchModeListenerToEnterSearch() {
+        mEditText.setText("abc");
+
+        verify(mSearchModeListener).enterSearchMode();
+        verifyNoMoreInteractions(mSearchModeListener);
+    }
+
+    @Test
+    public void afterTextChanged_shouldDoSearch() {
+        mEditText.setText("abc");
+
+        verify(mSearchAlgorithm).doSearch(eq("abc"), any());
+    }
+
+    @Test
+    public void afterTextChanged_shouldShowCancelButton() {
+        mEditText.setText("abc");
+
+        assertEquals(mCancelButton.getVisibility(), View.VISIBLE);
+    }
+
+    @Test
+    public void afterTextChanged_empty_shouldInformSearchModeListenerToExitSearch() {
+        mEditText.setText("");
+
+        verify(mSearchModeListener).exitSearchMode();
+        verifyNoMoreInteractions(mSearchModeListener);
+    }
+
+    @Test
+    public void afterTextChanged_empty_shouldCancelSearch() {
+        mEditText.setText("");
+
+        verify(mSearchAlgorithm).cancel(true);
+        verifyNoMoreInteractions(mSearchAlgorithm);
+    }
+
+    @Test
+    public void afterTextChanged_empty_shouldHideCancelButton() {
+        mEditText.setText("");
+
+        assertEquals(mCancelButton.getVisibility(), View.GONE);
+    }
+
+    @Test
+    public void cancelSearch_shouldInformSearchModeListenerToClearResultsAndExitSearch() {
+        mCancelButton.performClick();
+
+        verify(mSearchModeListener).exitSearchMode();
+    }
+
+    @Test
+    public void cancelSearch_shouldCancelSearch() {
+        mCancelButton.performClick();
+
+        verify(mSearchAlgorithm).cancel(true);
+        verifyNoMoreInteractions(mSearchAlgorithm);
+    }
+
+    @Test
+    public void cancelSearch_shouldClearSearchBar() {
+        mCancelButton.performClick();
+
+        assertEquals(mEditText.getText().toString(), "");
+    }
+}
diff --git a/tests/src/com/android/launcher3/widget/picker/util/WidgetsTableUtilsTest.java b/tests/src/com/android/launcher3/widget/picker/util/WidgetsTableUtilsTest.java
new file mode 100644
index 0000000..d6da776
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/picker/util/WidgetsTableUtilsTest.java
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker.util;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
+import static com.android.launcher3.util.WidgetUtils.createAppWidgetProviderInfo;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.graphics.Point;
+import android.graphics.drawable.Drawable;
+import android.os.UserHandle;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.icons.ComponentWithLabel;
+import com.android.launcher3.icons.IconCache;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.pm.ShortcutConfigActivityInfo;
+import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.widget.util.WidgetsTableUtils;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class WidgetsTableUtilsTest {
+    private static final String TEST_PACKAGE = "com.google.test";
+
+    @Mock
+    private IconCache mIconCache;
+
+    private Context mContext;
+    private InvariantDeviceProfile mTestProfile;
+    private WidgetItem mWidget1x1;
+    private WidgetItem mWidget2x2;
+    private WidgetItem mWidget2x3;
+    private WidgetItem mWidget2x4;
+    private WidgetItem mWidget4x4;
+
+    private WidgetItem mShortcut1;
+    private WidgetItem mShortcut2;
+    private WidgetItem mShortcut3;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = getApplicationContext();
+
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+
+        initTestWidgets();
+        initTestShortcuts();
+
+        doAnswer(invocation -> ((ComponentWithLabel) invocation.getArgument(0))
+                .getComponent().getPackageName())
+                .when(mIconCache).getTitleNoCache(any());
+    }
+
+
+    @Test
+    public void groupWidgetItemsIntoTable_widgetsOnly_maxSpansPerRow5_shouldGroupWidgetsInTable() {
+        List<WidgetItem> widgetItems = List.of(mWidget4x4, mWidget2x3, mWidget1x1, mWidget2x4,
+                mWidget2x2);
+
+        List<ArrayList<WidgetItem>> widgetItemInTable = WidgetsTableUtils.groupWidgetItemsIntoTable(
+                widgetItems, /* maxSpansPerRow= */ 5);
+
+        // Row 0: 1x1, 2x2
+        // Row 1: 2x3, 2x4
+        // Row 2: 4x4
+        assertThat(widgetItemInTable).hasSize(3);
+        assertThat(widgetItemInTable.get(0)).containsExactly(mWidget1x1, mWidget2x2);
+        assertThat(widgetItemInTable.get(1)).containsExactly(mWidget2x3, mWidget2x4);
+        assertThat(widgetItemInTable.get(2)).containsExactly(mWidget4x4);
+    }
+
+    @Test
+    public void groupWidgetItemsIntoTable_widgetsOnly_maxSpansPerRow4_shouldGroupWidgetsInTable() {
+        List<WidgetItem> widgetItems = List.of(mWidget4x4, mWidget2x3, mWidget1x1, mWidget2x4,
+                mWidget2x2);
+
+        List<ArrayList<WidgetItem>> widgetItemInTable = WidgetsTableUtils.groupWidgetItemsIntoTable(
+                widgetItems, /* maxSpansPerRow= */ 4);
+
+        // Row 0: 1x1, 2x2
+        // Row 1: 2x3,
+        // Row 2: 2x4,
+        // Row 3: 4x4
+        assertThat(widgetItemInTable).hasSize(4);
+        assertThat(widgetItemInTable.get(0)).containsExactly(mWidget1x1, mWidget2x2);
+        assertThat(widgetItemInTable.get(1)).containsExactly(mWidget2x3);
+        assertThat(widgetItemInTable.get(2)).containsExactly(mWidget2x4);
+        assertThat(widgetItemInTable.get(3)).containsExactly(mWidget4x4);
+    }
+
+    @Test
+    public void groupWidgetItemsIntoTable_mixItems_maxSpansPerRow4_shouldGroupWidgetsInTable() {
+        List<WidgetItem> widgetItems = List.of(mWidget4x4, mShortcut3, mWidget2x3, mShortcut1,
+                mWidget1x1, mShortcut2, mWidget2x4, mWidget2x2);
+
+        List<ArrayList<WidgetItem>> widgetItemInTable = WidgetsTableUtils.groupWidgetItemsIntoTable(
+                widgetItems, /* maxSpansPerRow= */ 4);
+
+        // Row 0: 1x1, 2x2
+        // Row 1: 2x3,
+        // Row 2: 2x4,
+        // Row 3: 4x4
+        // Row 4: shortcut3, shortcut1, shortcut2
+        assertThat(widgetItemInTable).hasSize(5);
+        assertThat(widgetItemInTable.get(0)).containsExactly(mWidget1x1, mWidget2x2);
+        assertThat(widgetItemInTable.get(1)).containsExactly(mWidget2x3);
+        assertThat(widgetItemInTable.get(2)).containsExactly(mWidget2x4);
+        assertThat(widgetItemInTable.get(3)).containsExactly(mWidget4x4);
+        assertThat(widgetItemInTable.get(4)).containsExactly(mShortcut3, mShortcut2, mShortcut1);
+    }
+
+    private void initTestWidgets() {
+        List<Point> widgetSizes = List.of(new Point(1, 1), new Point(2, 2), new Point(2, 3),
+                new Point(2, 4), new Point(4, 4));
+
+        ArrayList<WidgetItem> widgetItems = new ArrayList<>();
+        widgetSizes.stream().forEach(
+                widgetSize -> {
+                    AppWidgetProviderInfo info = createAppWidgetProviderInfo(
+                            ComponentName.createRelative(
+                                    TEST_PACKAGE,
+                                    ".WidgetProvider_" + widgetSize.x + "x" + widgetSize.y));
+                    LauncherAppWidgetProviderInfo widgetInfo =
+                            LauncherAppWidgetProviderInfo.fromProviderInfo(mContext, info);
+                    widgetInfo.spanX = widgetSize.x;
+                    widgetInfo.spanY = widgetSize.y;
+                    widgetItems.add(new WidgetItem(widgetInfo, mTestProfile, mIconCache));
+                }
+        );
+        mWidget1x1 = widgetItems.get(0);
+        mWidget2x2 = widgetItems.get(1);
+        mWidget2x3 = widgetItems.get(2);
+        mWidget2x4 = widgetItems.get(3);
+        mWidget4x4 = widgetItems.get(4);
+    }
+
+    private void initTestShortcuts() {
+        PackageManager packageManager = mContext.getPackageManager();
+        mShortcut1 = new WidgetItem(new TestShortcutConfigActivityInfo(
+                ComponentName.createRelative(TEST_PACKAGE, ".shortcut1"), UserHandle.CURRENT),
+                mIconCache, packageManager);
+        mShortcut2 = new WidgetItem(new TestShortcutConfigActivityInfo(
+                ComponentName.createRelative(TEST_PACKAGE, ".shortcut2"), UserHandle.CURRENT),
+                mIconCache, packageManager);
+        mShortcut3 = new WidgetItem(new TestShortcutConfigActivityInfo(
+                ComponentName.createRelative(TEST_PACKAGE, ".shortcut3"), UserHandle.CURRENT),
+                mIconCache, packageManager);
+
+    }
+
+    private final class TestShortcutConfigActivityInfo extends ShortcutConfigActivityInfo {
+
+        TestShortcutConfigActivityInfo(ComponentName componentName, UserHandle user) {
+            super(componentName, user);
+        }
+
+        @Override
+        public Drawable getFullResIcon(IconCache cache) {
+            return null;
+        }
+
+        @Override
+        public CharSequence getLabel(PackageManager pm) {
+            return null;
+        }
+    }
+}