Add Executor to the TestLooper

Add a method to obtain an Executor from a TestLooper: the executor
executes on a new Handler on the test looper.

Bug: 73088768
Test: new unit test for executor
Change-Id: Ib0aa10011116a4d998f8d3a7434939338d9b516d

tests/utils/testutils/java/android/os/test/TestLooper.java

@@ -18,6 +18,8 @@ package android.os.test;
 
 import static org.junit.Assert.assertTrue;
 
+import android.os.Handler;
+import android.os.HandlerExecutor;
 import android.os.Looper;
 import android.os.Message;
 import android.os.MessageQueue;
@@ -28,6 +30,7 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.concurrent.Executor;
 
 /**
  * Creates a looper whose message queue can be manipulated
@@ -83,6 +86,10 @@ public class TestLooper {
         return mLooper;
     }
 
+    public Executor getNewExecutor() {
+        return new HandlerExecutor(new Handler(getLooper()));
+    }
+
     private Message getMessageLinkedList() {
         try {
             MessageQueue queue = mLooper.getQueue();

tests/utils/testutils/java/android/os/test/TestLooperTest.java

@@ -21,6 +21,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 
@@ -37,6 +38,8 @@ import org.mockito.ArgumentCaptor;
 import org.mockito.InOrder;
 import org.mockito.MockitoAnnotations;
 
+import java.util.concurrent.Executor;
+
 /**
  * Test TestLooperAbstractTime which provides control over "time". Note that
  * real-time is being used as well. Therefore small time increments are NOT
@@ -48,6 +51,7 @@ public class TestLooperTest {
     private TestLooper mTestLooper;
     private Handler mHandler;
     private Handler mHandlerSpy;
+    private Executor mExecutor;
 
     @Rule
     public ErrorCollector collector = new ErrorCollector();
@@ -59,6 +63,7 @@ public class TestLooperTest {
         mTestLooper = new TestLooper();
         mHandler = new Handler(mTestLooper.getLooper());
         mHandlerSpy = spy(mHandler);
+        mExecutor = mTestLooper.getNewExecutor();
     }
 
     /**
@@ -92,6 +97,32 @@ public class TestLooperTest {
         inOrder.verify(mHandlerSpy, never()).handleMessage(any(Message.class));
     }
 
+    /**
+     * Basic test of the Executor with no time stamps: dispatch 4 executables, check that all 4
+     * executed in correct order.
+     */
+    @Test
+    public void testNoTimeMovementExecutor() {
+        final Runnable runnableA = mock(Runnable.class);
+        final Runnable runnableB = mock(Runnable.class);
+        final Runnable runnableC = mock(Runnable.class);
+
+        InOrder inOrder = inOrder(runnableA, runnableB, runnableC);
+
+        mExecutor.execute(runnableA);
+        mExecutor.execute(runnableB);
+        mExecutor.execute(runnableA);
+        mExecutor.execute(runnableC);
+        mTestLooper.dispatchAll();
+
+        inOrder.verify(runnableA).run();
+        inOrder.verify(runnableB).run();
+        inOrder.verify(runnableA).run();
+        inOrder.verify(runnableC).run();
+
+        inOrder.verifyNoMoreInteractions();
+    }
+
     /**
      * Test message sequence: A, B, C@5K, A@10K. Don't move time.
      * <p>