Use completeExceptionally instead of second future

The onError callback can use the same future as the onResult callback by
calling completeExceptionally.
This change is also removing the test for a specific exception message.
Testing for a specific exception message would mean that tests break if we
ever were to update them. If we decide that there is value to
distinguish between different types of
EthernetNetworkManagementException we should probably subclass it
internally.

Test: atest EthernetNetworkFactoryTest
Change-Id: Ib6f8cf79fc26e0f856c880cbe505b101f12aa187

tests/unit/java/com/android/server/ethernet/EthernetNetworkFactoryTest.java

@@ -20,9 +20,9 @@ import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
@@ -41,8 +41,8 @@ import android.app.test.MockAnswerUtil.AnswerWithArguments;
 import android.content.Context;
 import android.content.res.Resources;
 import android.net.ConnectivityManager;
-import android.net.EthernetNetworkSpecifier;
 import android.net.EthernetNetworkManagementException;
+import android.net.EthernetNetworkSpecifier;
 import android.net.INetworkInterfaceOutcomeReceiver;
 import android.net.IpConfiguration;
 import android.net.LinkAddress;
@@ -59,14 +59,11 @@ import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.test.TestLooper;
-import android.util.Pair;
 
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
-import com.android.connectivity.resources.R;
 import com.android.net.module.util.InterfaceParams;
-
 import com.android.testutils.DevSdkIgnoreRule;
 
 import org.junit.After;
@@ -79,6 +76,7 @@ import org.mockito.MockitoAnnotations;
 
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
 @RunWith(AndroidJUnit4.class)
@@ -362,7 +360,7 @@ public class EthernetNetworkFactoryTest {
 
         assertFalse(ret);
         verifyNoStopOrStart();
-        listener.expectOnErrorWithMessage("can't be updated as it is not available");
+        listener.expectOnError();
     }
 
     @Test
@@ -376,7 +374,7 @@ public class EthernetNetworkFactoryTest {
 
         assertFalse(ret);
         verifyNoStopOrStart();
-        listener.expectOnErrorWithMessage("No changes");
+        listener.expectOnError();
     }
 
     @Test
@@ -626,8 +624,6 @@ public class EthernetNetworkFactoryTest {
     private static final class TestNetworkManagementListener
             implements INetworkInterfaceOutcomeReceiver {
         private final CompletableFuture<String> mResult = new CompletableFuture<>();
-        private final CompletableFuture<EthernetNetworkManagementException> mError =
-                new CompletableFuture<>();
 
         @Override
         public void onResult(@NonNull String iface) {
@@ -636,19 +632,21 @@ public class EthernetNetworkFactoryTest {
 
         @Override
         public void onError(@NonNull EthernetNetworkManagementException exception) {
-            mError.complete(exception);
+            mResult.completeExceptionally(exception);
         }
 
         String expectOnResult() throws Exception {
             return mResult.get(TIMEOUT_MS, TimeUnit.MILLISECONDS);
         }
 
-        EthernetNetworkManagementException expectOnError() throws Exception {
-            return mError.get(TIMEOUT_MS, TimeUnit.MILLISECONDS);
-        }
-
-        void expectOnErrorWithMessage(String msg) throws Exception {
-            assertTrue(expectOnError().getMessage().contains(msg));
+        void expectOnError() throws Exception {
+            assertThrows(EthernetNetworkManagementException.class, () -> {
+                try {
+                    mResult.get();
+                } catch (ExecutionException e) {
+                    throw e.getCause();
+                }
+            });
         }
 
         @Override
@@ -723,7 +721,7 @@ public class EthernetNetworkFactoryTest {
         mNetFactory.updateInterface(iface, ipConfiguration, capabilities, failedListener);
         interruptingRunnable.run();
 
-        failedListener.expectOnErrorWithMessage("aborted");
+        failedListener.expectOnError();
     }
 
     @Test
@@ -754,7 +752,7 @@ public class EthernetNetworkFactoryTest {
         mNetFactory.updateInterface(TEST_IFACE, ipConfiguration, capabilities, listener);
 
         verifyNoStopOrStart();
-        listener.expectOnErrorWithMessage("can't be updated as it is not available");
+        listener.expectOnError();
     }
 
     @Test