core: enhance ManagedChannelBuilder.overrideAuthority()

Enhance `ManagedChannelBuilder.overrideAuthority()` to make it impossible to use a different authority to a backend by wrapping ClientTransportFactory.newClientTransport() and setting ClientTransportOptions’ authority. To avoid confusing the LB policy, it would need to keep the original addresses to return during `Subchannel.getAddresses()`

The class `OverrideAuthorityNameResolverFactory` is deleted and its logic is moved into `ManagedChannelImpl`.

api/src/main/java/io/grpc/EquivalentAddressGroup.java

@@ -37,6 +37,9 @@ public final class EquivalentAddressGroup {
 
   /**
    * The authority to be used when constructing Subchannels for this EquivalentAddressGroup.
+   * However, if the channel has overridden authority via
+   * {@link ManagedChannelBuilder#overrideAuthority(String)}, the transport will use the channel's
+   * authority override.
    */
   @Attr
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/6138")

api/src/main/java/io/grpc/ManagedChannelBuilder.java

@@ -163,6 +163,9 @@ public abstract class ManagedChannelBuilder<T extends ManagedChannelBuilder<T>>
    * Overrides the authority used with TLS and HTTP virtual hosting. It does not change what host is
    * actually connected to. Is commonly in the form {@code host:port}.
    *
+   * <p>If the channel builder overrides authority, any authority override from name resolution
+   * result (via {@link EquivalentAddressGroup#ATTR_AUTHORITY_OVERRIDE}) will be discarded.
+   *
    * <p>This method is intended for testing, but may safely be used outside of tests as an
    * alternative to DNS overrides.
    *

core/src/main/java/io/grpc/internal/ManagedChannelImpl.java

@@ -22,6 +22,7 @@ import static com.google.common.base.Preconditions.checkState;
 import static io.grpc.ConnectivityState.IDLE;
 import static io.grpc.ConnectivityState.SHUTDOWN;
 import static io.grpc.ConnectivityState.TRANSIENT_FAILURE;
+import static io.grpc.EquivalentAddressGroup.ATTR_AUTHORITY_OVERRIDE;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
@@ -152,6 +153,8 @@ final class ManagedChannelImpl extends ManagedChannel implements
 
   private final InternalLogId logId;
   private final String target;
+  @Nullable
+  private final String authorityOverride;
   private final NameResolverRegistry nameResolverRegistry;
   private final NameResolver.Factory nameResolverFactory;
   private final NameResolver.Args nameResolverArgs;
@@ -361,7 +364,8 @@ final class ManagedChannelImpl extends ManagedChannel implements
       nameResolver.shutdown();
       nameResolverStarted = false;
       if (channelIsActive) {
-        nameResolver = getNameResolver(target, nameResolverFactory, nameResolverArgs);
+        nameResolver = getNameResolver(
+            target, authorityOverride, nameResolverFactory, nameResolverArgs);
       } else {
         nameResolver = null;
       }
@@ -612,7 +616,6 @@ final class ManagedChannelImpl extends ManagedChannel implements
         logId, builder.maxTraceEvents, timeProvider.currentTimeNanos(),
         "Channel for '" + target + "'");
     channelLogger = new ChannelLoggerImpl(channelTracer, timeProvider);
-    this.nameResolverFactory = builder.getNameResolverFactory();
     ProxyDetector proxyDetector =
         builder.proxyDetector != null ? builder.proxyDetector : GrpcUtil.DEFAULT_PROXY_DETECTOR;
     this.retryEnabled = builder.retryEnabled && !builder.temporarilyDisableRetry;
@@ -644,7 +647,10 @@ final class ManagedChannelImpl extends ManagedChannel implements
                   }
                 })
             .build();
-    this.nameResolver = getNameResolver(target, nameResolverFactory, nameResolverArgs);
+    this.authorityOverride = builder.authorityOverride;
+    this.nameResolverFactory = builder.nameResolverFactory;
+    this.nameResolver = getNameResolver(
+        target, authorityOverride, nameResolverFactory, nameResolverArgs);
     this.balancerRpcExecutorPool = checkNotNull(balancerRpcExecutorPool, "balancerRpcExecutorPool");
     this.balancerRpcExecutorHolder = new ExecutorHolder(balancerRpcExecutorPool);
     this.delayedTransport = new DelayedClientTransport(this.executor, this.syncContext);
@@ -715,9 +721,8 @@ final class ManagedChannelImpl extends ManagedChannel implements
     }
   }
 
-  @VisibleForTesting
-  static NameResolver getNameResolver(String target, NameResolver.Factory nameResolverFactory,
-      NameResolver.Args nameResolverArgs) {
+  private static NameResolver getNameResolver(
+      String target, NameResolver.Factory nameResolverFactory, NameResolver.Args nameResolverArgs) {
     // Finding a NameResolver. Try using the target string as the URI. If that fails, try prepending
     // "dns:///".
     URI targetUri = null;
@@ -760,6 +765,22 @@ final class ManagedChannelImpl extends ManagedChannel implements
         target, uriSyntaxErrors.length() > 0 ? " (" + uriSyntaxErrors + ")" : ""));
   }
 
+  @VisibleForTesting
+  static NameResolver getNameResolver(
+      String target, @Nullable final String overrideAuthority,
+      NameResolver.Factory nameResolverFactory, NameResolver.Args nameResolverArgs) {
+    NameResolver resolver = getNameResolver(target, nameResolverFactory, nameResolverArgs);
+    if (overrideAuthority == null) {
+      return resolver;
+    }
+    return new ForwardingNameResolver(resolver) {
+      @Override
+      public String getServiceAuthority() {
+        return overrideAuthority;
+      }
+    };
+  }
+
   @VisibleForTesting
   InternalConfigSelector getConfigSelector() {
     return realChannel.configSelector.get();
@@ -1850,12 +1871,19 @@ final class ManagedChannelImpl extends ManagedChannel implements
     final InternalLogId subchannelLogId;
     final ChannelLoggerImpl subchannelLogger;
     final ChannelTracer subchannelTracer;
+    List<EquivalentAddressGroup> addressGroups;
     InternalSubchannel subchannel;
     boolean started;
     boolean shutdown;
     ScheduledHandle delayedShutdownTask;
 
     SubchannelImpl(CreateSubchannelArgs args, LbHelperImpl helper) {
+      addressGroups = args.getAddresses();
+      if (authorityOverride != null) {
+        List<EquivalentAddressGroup> eagsWithoutOverrideAttr =
+            stripOverrideAuthorityAttributes(args.getAddresses());
+        args = args.toBuilder().setAddresses(eagsWithoutOverrideAttr).build();
+      }
       this.args = checkNotNull(args, "args");
       this.helper = checkNotNull(helper, "helper");
       subchannelLogId = InternalLogId.allocate("Subchannel", /*details=*/ authority());
@@ -1992,7 +2020,7 @@ final class ManagedChannelImpl extends ManagedChannel implements
     public List<EquivalentAddressGroup> getAllAddresses() {
       syncContext.throwIfNotInThisSynchronizationContext();
       checkState(started, "not started");
-      return subchannel.getAddressGroups();
+      return addressGroups;
     }
 
     @Override
@@ -2029,8 +2057,24 @@ final class ManagedChannelImpl extends ManagedChannel implements
     @Override
     public void updateAddresses(List<EquivalentAddressGroup> addrs) {
       syncContext.throwIfNotInThisSynchronizationContext();
+      addressGroups = addrs;
+      if (authorityOverride != null) {
+        addrs = stripOverrideAuthorityAttributes(addrs);
+      }
       subchannel.updateAddresses(addrs);
     }
+
+    private List<EquivalentAddressGroup> stripOverrideAuthorityAttributes(
+        List<EquivalentAddressGroup> eags) {
+      List<EquivalentAddressGroup> eagsWithoutOverrideAttr = new ArrayList<>();
+      for (EquivalentAddressGroup eag : eags) {
+        EquivalentAddressGroup eagWithoutOverrideAttr = new EquivalentAddressGroup(
+            eag.getAddresses(),
+            eag.getAttributes().toBuilder().discard(ATTR_AUTHORITY_OVERRIDE).build());
+        eagsWithoutOverrideAttr.add(eagWithoutOverrideAttr);
+      }
+      return Collections.unmodifiableList(eagsWithoutOverrideAttr);
+    }
   }
 
   @Override

core/src/main/java/io/grpc/internal/ManagedChannelImplBuilder.java

@@ -108,7 +108,7 @@ public final class ManagedChannelImplBuilder
   final NameResolverRegistry nameResolverRegistry = NameResolverRegistry.getDefaultRegistry();
 
   // Access via getter, which may perform authority override as needed
-  private NameResolver.Factory nameResolverFactory = nameResolverRegistry.asFactory();
+  NameResolver.Factory nameResolverFactory = nameResolverRegistry.asFactory();
 
   final String target;
   @Nullable
@@ -123,7 +123,7 @@ public final class ManagedChannelImplBuilder
   String userAgent;
 
   @Nullable
-  private String authorityOverride;
+  String authorityOverride;
 
   String defaultLbPolicy = GrpcUtil.DEFAULT_LB_POLICY;
 
@@ -393,12 +393,6 @@ public final class ManagedChannelImplBuilder
     return this;
   }
 
-  @Nullable
-  @VisibleForTesting
-  String getOverrideAuthority() {
-    return authorityOverride;
-  }
-
   @Override
   public ManagedChannelImplBuilder idleTimeout(long value, TimeUnit unit) {
     checkArgument(value > 0, "idle timeout is %s, but must be positive", value);
@@ -699,17 +693,6 @@ public final class ManagedChannelImplBuilder
     return channelBuilderDefaultPortProvider.getDefaultPort();
   }
 
-  /**
-   * Returns a {@link NameResolver.Factory} for the channel.
-   */
-  NameResolver.Factory getNameResolverFactory() {
-    if (authorityOverride == null) {
-      return nameResolverFactory;
-    } else {
-      return new OverrideAuthorityNameResolverFactory(nameResolverFactory, authorityOverride);
-    }
-  }
-
   private static class DirectAddressNameResolverFactory extends NameResolver.Factory {
     final SocketAddress address;
     final String authority;

core/src/main/java/io/grpc/internal/OverrideAuthorityNameResolverFactory.java

@@ -1,63 +0,0 @@
-/*
- * Copyright 2017 The gRPC Authors
- *
- * 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 io.grpc.internal;
-
-import io.grpc.NameResolver;
-import java.net.URI;
-import javax.annotation.Nullable;
-
-/**
- * A wrapper class that overrides the authority of a NameResolver, while preserving all other
- * functionality.
- */
-final class OverrideAuthorityNameResolverFactory extends NameResolver.Factory {
-  private final NameResolver.Factory delegate;
-  private final String authorityOverride;
-
-  /**
-   * Constructor for the {@link NameResolver.Factory}
-   *
-   * @param delegate The actual underlying factory that will produce the a {@link NameResolver}
-   * @param authorityOverride The authority that will be returned by {@link
-   *   NameResolver#getServiceAuthority()}
-   */
-  OverrideAuthorityNameResolverFactory(NameResolver.Factory delegate, String authorityOverride) {
-    this.delegate = delegate;
-    this.authorityOverride = authorityOverride;
-  }
-
-  @Nullable
-  @Override
-  public NameResolver newNameResolver(URI targetUri, NameResolver.Args args) {
-    final NameResolver resolver = delegate.newNameResolver(targetUri, args);
-    // Do not wrap null values. We do not want to impede error signaling.
-    if (resolver == null) {
-      return null;
-    }
-    return new ForwardingNameResolver(resolver) {
-      @Override
-      public String getServiceAuthority() {
-        return authorityOverride;
-      }
-    };
-  }
-
-  @Override
-  public String getDefaultScheme() {
-    return delegate.getDefaultScheme();
-  }
-}

core/src/test/java/io/grpc/internal/ManagedChannelImplBuilderTest.java

@@ -180,7 +180,7 @@ public class ManagedChannelImplBuilderTest {
 
   @Test
   public void nameResolverFactory_default() {
-    assertNotNull(builder.getNameResolverFactory());
+    assertNotNull(builder.nameResolverFactory);
   }
 
   @Test
@@ -188,16 +188,16 @@ public class ManagedChannelImplBuilderTest {
   public void nameResolverFactory_normal() {
     NameResolver.Factory nameResolverFactory = mock(NameResolver.Factory.class);
     assertEquals(builder, builder.nameResolverFactory(nameResolverFactory));
-    assertEquals(nameResolverFactory, builder.getNameResolverFactory());
+    assertEquals(nameResolverFactory, builder.nameResolverFactory);
   }
 
   @Test
   @SuppressWarnings("deprecation")
   public void nameResolverFactory_null() {
-    NameResolver.Factory defaultValue = builder.getNameResolverFactory();
+    NameResolver.Factory defaultValue = builder.nameResolverFactory;
     builder.nameResolverFactory(mock(NameResolver.Factory.class));
     assertEquals(builder, builder.nameResolverFactory(null));
-    assertEquals(defaultValue, builder.getNameResolverFactory());
+    assertEquals(defaultValue, builder.nameResolverFactory);
   }
 
   @Test(expected = IllegalStateException.class)
@@ -334,14 +334,14 @@ public class ManagedChannelImplBuilderTest {
 
   @Test
   public void overrideAuthority_default() {
-    assertNull(builder.getOverrideAuthority());
+    assertNull(builder.authorityOverride);
   }
 
   @Test
   public void overrideAuthority_normal() {
     String overrideAuthority = "best-authority";
     assertEquals(builder, builder.overrideAuthority(overrideAuthority));
-    assertEquals(overrideAuthority, builder.getOverrideAuthority());
+    assertEquals(overrideAuthority, builder.authorityOverride);
   }
 
   @Test(expected = NullPointerException.class)
@@ -354,14 +354,6 @@ public class ManagedChannelImplBuilderTest {
     builder.overrideAuthority("not_allowed");
   }
 
-  @Test
-  public void overrideAuthority_getNameResolverFactory() {
-    assertNull(builder.getOverrideAuthority());
-    assertFalse(builder.getNameResolverFactory() instanceof OverrideAuthorityNameResolverFactory);
-    builder.overrideAuthority("google.com");
-    assertTrue(builder.getNameResolverFactory() instanceof OverrideAuthorityNameResolverFactory);
-  }
-
   @Test
   public void checkAuthority_validAuthorityAllowed() {
     assertEquals(DUMMY_AUTHORITY_VALID, builder.checkAuthority(DUMMY_AUTHORITY_VALID));

core/src/test/java/io/grpc/internal/ManagedChannelImplGetNameResolverTest.java

@@ -16,6 +16,7 @@
 
 package io.grpc.internal;
 
+import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
@@ -32,7 +33,8 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Unit tests for {@link ManagedChannelImpl#getNameResolver}. */
+/** Unit tests for {@link ManagedChannelImpl#getNameResolver(
+ * String, String,NameResolver.Factory, NameResolver.Args)}. */
 @RunWith(JUnit4.class)
 public class ManagedChannelImplGetNameResolverTest {
   private static final NameResolver.Args NAMERESOLVER_ARGS = NameResolver.Args.newBuilder()
@@ -60,6 +62,17 @@ public class ManagedChannelImplGetNameResolverTest {
         new URI("defaultscheme", "", "/foo.googleapis.com:8080", null));
   }
 
+  @Test
+  public void validAuthorityTarget_overrideAuthority() throws Exception {
+    String target = "foo.googleapis.com:8080";
+    String overrideAuthority = "override.authority";
+    URI expectedUri = new URI("defaultscheme", "", "/foo.googleapis.com:8080", null);
+    NameResolver.Factory nameResolverFactory = new FakeNameResolverFactory(expectedUri.getScheme());
+    NameResolver nameResolver = ManagedChannelImpl.getNameResolver(
+        target, overrideAuthority, nameResolverFactory, NAMERESOLVER_ARGS);
+    assertThat(nameResolver.getServiceAuthority()).isEqualTo(overrideAuthority);
+  }
+
   @Test
   public void validUriTarget() throws Exception {
     testValidTarget("scheme:///foo.googleapis.com:8080", "scheme:///foo.googleapis.com:8080",
@@ -116,7 +129,7 @@ public class ManagedChannelImplGetNameResolverTest {
     };
     try {
       ManagedChannelImpl.getNameResolver(
-          "foo.googleapis.com:8080", nameResolverFactory, NAMERESOLVER_ARGS);
+          "foo.googleapis.com:8080", null, nameResolverFactory, NAMERESOLVER_ARGS);
       fail("Should fail");
     } catch (IllegalArgumentException e) {
       // expected
@@ -126,7 +139,7 @@ public class ManagedChannelImplGetNameResolverTest {
   private void testValidTarget(String target, String expectedUriString, URI expectedUri) {
     NameResolver.Factory nameResolverFactory = new FakeNameResolverFactory(expectedUri.getScheme());
     FakeNameResolver nameResolver = (FakeNameResolver) ManagedChannelImpl.getNameResolver(
-        target, nameResolverFactory, NAMERESOLVER_ARGS);
+        target, null, nameResolverFactory, NAMERESOLVER_ARGS);
     assertNotNull(nameResolver);
     assertEquals(expectedUri, nameResolver.uri);
     assertEquals(expectedUriString, nameResolver.uri.toString());
@@ -137,7 +150,7 @@ public class ManagedChannelImplGetNameResolverTest {
 
     try {
       FakeNameResolver nameResolver = (FakeNameResolver) ManagedChannelImpl.getNameResolver(
-          target, nameResolverFactory, NAMERESOLVER_ARGS);
+          target, null, nameResolverFactory, NAMERESOLVER_ARGS);
       fail("Should have failed, but got resolver with " + nameResolver.uri);
     } catch (IllegalArgumentException e) {
       // expected

core/src/test/java/io/grpc/internal/ManagedChannelImplTest.java

@@ -24,6 +24,7 @@ import static io.grpc.ConnectivityState.IDLE;
 import static io.grpc.ConnectivityState.READY;
 import static io.grpc.ConnectivityState.SHUTDOWN;
 import static io.grpc.ConnectivityState.TRANSIENT_FAILURE;
+import static io.grpc.EquivalentAddressGroup.ATTR_AUTHORITY_OVERRIDE;
 import static junit.framework.TestCase.assertNotSame;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -380,6 +381,64 @@ public class ManagedChannelImplTest {
     }
   }
 
+  @Test
+  public void createSubchannel_resolverOverrideAuthority() {
+    EquivalentAddressGroup addressGroup = new EquivalentAddressGroup(
+        socketAddress,
+        Attributes.newBuilder()
+            .set(ATTR_AUTHORITY_OVERRIDE, "resolver.override.authority")
+            .build());
+    channelBuilder.nameResolverFactory(
+        new FakeNameResolverFactory.Builder(expectedUri)
+            .setServers(Collections.singletonList(addressGroup))
+            .build());
+    createChannel();
+
+    Subchannel subchannel =
+        createSubchannelSafely(helper, addressGroup, Attributes.EMPTY, subchannelStateListener);
+    requestConnectionSafely(helper, subchannel);
+    ArgumentCaptor<ClientTransportOptions> transportOptionCaptor = ArgumentCaptor.forClass(null);
+    verify(mockTransportFactory)
+        .newClientTransport(
+            any(SocketAddress.class), transportOptionCaptor.capture(), any(ChannelLogger.class));
+    assertThat(transportOptionCaptor.getValue().getAuthority())
+        .isEqualTo("resolver.override.authority");
+  }
+
+  @Test
+  public void createSubchannel_channelBuilderOverrideAuthority() {
+    channelBuilder.overrideAuthority("channel-builder.override.authority");
+    EquivalentAddressGroup addressGroup = new EquivalentAddressGroup(
+        socketAddress,
+        Attributes.newBuilder()
+            .set(ATTR_AUTHORITY_OVERRIDE, "resolver.override.authority")
+            .build());
+    channelBuilder.nameResolverFactory(
+        new FakeNameResolverFactory.Builder(expectedUri)
+            .setServers(Collections.singletonList(addressGroup))
+            .build());
+    createChannel();
+
+    final Subchannel subchannel =
+        createSubchannelSafely(helper, addressGroup, Attributes.EMPTY, subchannelStateListener);
+    requestConnectionSafely(helper, subchannel);
+    ArgumentCaptor<ClientTransportOptions> transportOptionCaptor = ArgumentCaptor.forClass(null);
+    verify(mockTransportFactory)
+        .newClientTransport(
+            any(SocketAddress.class), transportOptionCaptor.capture(), any(ChannelLogger.class));
+    assertThat(transportOptionCaptor.getValue().getAuthority())
+        .isEqualTo("channel-builder.override.authority");
+    final List<EquivalentAddressGroup> subchannelEags = new ArrayList<>();
+    helper.getSynchronizationContext().execute(
+        new Runnable() {
+          @Override
+          public void run() {
+            subchannelEags.addAll(subchannel.getAllAddresses());
+          }
+        });
+    assertThat(subchannelEags).isEqualTo(ImmutableList.of(addressGroup));
+  }
+
   @Test
   public void idleModeDisabled() {
     channelBuilder.nameResolverFactory(

core/src/test/java/io/grpc/internal/OverrideAuthorityNameResolverTest.java

@@ -1,95 +0,0 @@
-/*
- * Copyright 2017 The gRPC Authors
- *
- * 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 io.grpc.internal;
-
-import static junit.framework.TestCase.assertNotNull;
-import static org.junit.Assert.assertEquals;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import io.grpc.ChannelLogger;
-import io.grpc.NameResolver;
-import io.grpc.NameResolver.ServiceConfigParser;
-import io.grpc.ProxyDetector;
-import io.grpc.SynchronizationContext;
-import java.lang.Thread.UncaughtExceptionHandler;
-import java.net.URI;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-/** Unit tests for {@link OverrideAuthorityNameResolverFactory}. */
-@RunWith(JUnit4.class)
-public class OverrideAuthorityNameResolverTest {
-  private static final NameResolver.Args ARGS = NameResolver.Args.newBuilder()
-      .setDefaultPort(8080)
-      .setProxyDetector(mock(ProxyDetector.class))
-      .setSynchronizationContext(new SynchronizationContext(mock(UncaughtExceptionHandler.class)))
-      .setServiceConfigParser(mock(ServiceConfigParser.class))
-      .setChannelLogger(mock(ChannelLogger.class))
-      .build();
-
-  @Test
-  public void overridesAuthority() {
-    NameResolver nameResolverMock = mock(NameResolver.class);
-    NameResolver.Factory wrappedFactory = mock(NameResolver.Factory.class);
-    when(wrappedFactory.newNameResolver(any(URI.class), any(NameResolver.Args.class)))
-        .thenReturn(nameResolverMock);
-    String override = "override:5678";
-    NameResolver.Factory factory =
-        new OverrideAuthorityNameResolverFactory(wrappedFactory, override);
-    NameResolver nameResolver = factory.newNameResolver(URI.create("dns:///localhost:443"), ARGS);
-    assertNotNull(nameResolver);
-    assertEquals(override, nameResolver.getServiceAuthority());
-  }
-
-  @Test
-  public void wontWrapNull() {
-    NameResolver.Factory wrappedFactory = mock(NameResolver.Factory.class);
-    when(wrappedFactory.newNameResolver(any(URI.class), any(NameResolver.Args.class)))
-        .thenReturn(null);
-    NameResolver.Factory factory =
-        new OverrideAuthorityNameResolverFactory(wrappedFactory, "override:5678");
-    assertEquals(null,
-        factory.newNameResolver(URI.create("dns:///localhost:443"), ARGS));
-  }
-
-  @Test
-  public void forwardsNonOverridenCalls() {
-    NameResolver.Factory wrappedFactory = mock(NameResolver.Factory.class);
-    NameResolver mockResolver = mock(NameResolver.class);
-    when(wrappedFactory.newNameResolver(any(URI.class), any(NameResolver.Args.class)))
-        .thenReturn(mockResolver);
-    NameResolver.Factory factory =
-        new OverrideAuthorityNameResolverFactory(wrappedFactory, "override:5678");
-    NameResolver overrideResolver =
-        factory.newNameResolver(URI.create("dns:///localhost:443"), ARGS);
-    assertNotNull(overrideResolver);
-    NameResolver.Listener2 listener = mock(NameResolver.Listener2.class);
-
-    overrideResolver.start(listener);
-    verify(mockResolver).start(listener);
-
-    overrideResolver.shutdown();
-    verify(mockResolver).shutdown();
-
-    overrideResolver.refresh();
-    verify(mockResolver).refresh();
-  }
-}