diff --git a/robolectric_tests/Android.mk b/robolectric_tests/Android.mk
new file mode 100644
index 0000000..5011764
--- /dev/null
+++ b/robolectric_tests/Android.mk
@@ -0,0 +1,53 @@
+# Copyright (C) 2018 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.
+
+#############################################
+# Launcher Robolectric test target.         #
+#############################################
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := LauncherRoboTests
+LOCAL_SDK_VERSION := current
+LOCAL_SRC_FILES := $(call all-java-files-under, src)
+LOCAL_STATIC_JAVA_LIBRARIES := \
+    androidx.test.runner \
+    androidx.test.rules \
+    mockito-robolectric-prebuilt \
+    truth-prebuilt
+LOCAL_JAVA_LIBRARIES := \
+    platform-robolectric-3.6.1-prebuilt
+
+LOCAL_INSTRUMENTATION_FOR := Launcher3
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_STATIC_JAVA_LIBRARY)
+
+############################################
+# Target to run the previous target.       #
+############################################
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := RunLauncherRoboTests
+LOCAL_SDK_VERSION := current
+LOCAL_JAVA_LIBRARIES := \
+    LauncherRoboTests
+
+LOCAL_TEST_PACKAGE := Launcher3
+
+LOCAL_INSTRUMENT_SOURCE_DIRS := $(dir $(LOCAL_PATH))../src \
+
+LOCAL_ROBOTEST_TIMEOUT := 36000
+
+include prebuilts/misc/common/robolectric/3.6.1/run_robotests.mk
diff --git a/robolectric_tests/src/com/android/launcher3/util/IntSetTest.java b/robolectric_tests/src/com/android/launcher3/util/IntSetTest.java
new file mode 100644
index 0000000..faec380
--- /dev/null
+++ b/robolectric_tests/src/com/android/launcher3/util/IntSetTest.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2018 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 static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Robolectric unit tests for {@link IntSet}
+ */
+@RunWith(RobolectricTestRunner.class)
+@Config(sdk = 26)
+public class IntSetTest {
+
+    @Test
+    public void shouldBeEmptyInitially() {
+        IntSet set = new IntSet();
+        assertThat(set.size()).isEqualTo(0);
+    }
+
+    @Test
+    public void oneElementSet() {
+        IntSet set = new IntSet();
+        set.add(2);
+        assertThat(set.size()).isEqualTo(1);
+        assertTrue(set.contains(2));
+        assertFalse(set.contains(1));
+    }
+
+
+    @Test
+    public void twoElementSet() {
+        IntSet set = new IntSet();
+        set.add(2);
+        set.add(1);
+        assertThat(set.size()).isEqualTo(2);
+        assertTrue(set.contains(2));
+        assertTrue(set.contains(1));
+    }
+
+    @Test
+    public void threeElementSet() {
+        IntSet set = new IntSet();
+        set.add(2);
+        set.add(1);
+        set.add(10);
+        assertThat(set.size()).isEqualTo(3);
+        assertEquals("1, 2, 10", set.mArray.toConcatString());
+    }
+
+
+    @Test
+    public void duplicateEntries() {
+        IntSet set = new IntSet();
+        set.add(2);
+        set.add(2);
+        assertEquals(1, set.size());
+    }
+}