ConnectivityServiceTest: more informative assert failures

Bug: 62918393
Test: runtest frameworks-net
Change-Id: I90c211dc6d6262475924ecabc2863c47aec5a0b9

tests/net/java/com/android/server/ConnectivityServiceTest.java

@@ -897,7 +897,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         assertNull(mCm.getActiveNetwork());
         assertNull(mCm.getActiveNetworkForUid(Process.myUid()));
         // Test getAllNetworks()
-        assertEquals(0, mCm.getAllNetworks().length);
+        assertEmpty(mCm.getAllNetworks());
     }
 
     /**
@@ -938,7 +938,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         mCellNetworkAgent.connect(true);
         waitFor(cv);
         verifyActiveNetwork(TRANSPORT_CELLULAR);
-        assertEquals(2, mCm.getAllNetworks().length);
+        assertLength(2, mCm.getAllNetworks());
         assertTrue(mCm.getAllNetworks()[0].equals(mCm.getActiveNetwork()) ||
                 mCm.getAllNetworks()[1].equals(mCm.getActiveNetwork()));
         assertTrue(mCm.getAllNetworks()[0].equals(mWiFiNetworkAgent.getNetwork()) ||
@@ -948,7 +948,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         mWiFiNetworkAgent.connect(true);
         waitFor(cv);
         verifyActiveNetwork(TRANSPORT_WIFI);
-        assertEquals(2, mCm.getAllNetworks().length);
+        assertLength(2, mCm.getAllNetworks());
         assertTrue(mCm.getAllNetworks()[0].equals(mCm.getActiveNetwork()) ||
                 mCm.getAllNetworks()[1].equals(mCm.getActiveNetwork()));
         assertTrue(mCm.getAllNetworks()[0].equals(mCellNetworkAgent.getNetwork()) ||
@@ -956,9 +956,9 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         // Test cellular linger timeout.
         waitFor(mCellNetworkAgent.getDisconnectedCV());
         waitForIdle();
-        assertEquals(1, mCm.getAllNetworks().length);
+        assertLength(1, mCm.getAllNetworks());
         verifyActiveNetwork(TRANSPORT_WIFI);
-        assertEquals(1, mCm.getAllNetworks().length);
+        assertLength(1, mCm.getAllNetworks());
         assertEquals(mCm.getAllNetworks()[0], mCm.getActiveNetwork());
         // Test WiFi disconnect.
         cv = waitForConnectivityBroadcasts(1);
@@ -1898,7 +1898,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         mCellNetworkAgent.connectWithoutInternet();
         waitFor(cv);
         waitForIdle();
-        assertEquals(0, mCm.getAllNetworks().length);
+        assertEmpty(mCm.getAllNetworks());
         verifyNoNetwork();
 
         // Test bringing up validated WiFi.
@@ -2572,7 +2572,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         assertTrue(testFactory.getMyStartRequested());
 
         // Bring up cell data and check that the factory stops looking.
-        assertEquals(1, mCm.getAllNetworks().length);
+        assertLength(1, mCm.getAllNetworks());
         mCellNetworkAgent = new MockNetworkAgent(TRANSPORT_CELLULAR);
         testFactory.expectAddRequests(2);  // Because the cell request changes score twice.
         mCellNetworkAgent.connect(true);
@@ -2583,7 +2583,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         // Check that cell data stays up.
         waitForIdle();
         verifyActiveNetwork(TRANSPORT_WIFI);
-        assertEquals(2, mCm.getAllNetworks().length);
+        assertLength(2, mCm.getAllNetworks());
 
         // Turn off mobile data always on and expect the request to disappear...
         testFactory.expectRemoveRequests(1);
@@ -2592,7 +2592,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
 
         // ...  and cell data to be torn down.
         cellNetworkCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
-        assertEquals(1, mCm.getAllNetworks().length);
+        assertLength(1, mCm.getAllNetworks());
 
         testFactory.unregister();
         mCm.unregisterNetworkCallback(cellNetworkCallback);
@@ -3297,7 +3297,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         assertNull(mCm.getActiveNetworkInfo());
 
         Network[] allNetworks = mCm.getAllNetworks();
-        assertEquals(1, allNetworks.length);
+        assertLength(1, allNetworks);
         Network network = allNetworks[0];
         NetworkCapabilities capabilities = mCm.getNetworkCapabilities(network);
         assertTrue(capabilities.hasTransport(TRANSPORT_LOWPAN));
@@ -3315,7 +3315,7 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         assertNull(mCm.getActiveNetwork());
         // TODO: getAllNetworkInfo is dirty and returns a non-empty array rght from the start
         // of this test. Fix it and uncomment the assert below.
-        //assertEquals(0, mCm.getAllNetworkInfo().length);
+        //assertEmpty(mCm.getAllNetworkInfo());
 
         // Disconnect lowpan.
         lowpanNetwork.disconnect();
@@ -3361,6 +3361,17 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         }
     }
 
+    private static <T> void assertEmpty(T[] ts) {
+        int length = ts.length;
+        assertEquals("expected empty array, but length was " + length, 0, length);
+    }
+
+    private static <T> void assertLength(int expected, T[] got) {
+        int length = got.length;
+        assertEquals(String.format("expected array of length %s, but length was %s for %s",
+                expected, length, Arrays.toString(got)), expected, length);
+    }
+
     /* test utilities */
     // TODO: eliminate all usages of sleepFor and replace by proper timeouts/waitForIdle.
     static private void sleepFor(int ms) {