Remove IP literal check for InetAddressResolver (#1120)

JAVA-4963

Author: jyemin

driver-core/src/main/com/mongodb/internal/connection/ServerAddressWithResolver.java

@@ -62,7 +62,7 @@ public InetSocketAddress getSocketAddress() {
 
     @Override
     public List<InetSocketAddress> getSocketAddresses() {
-        if (resolver == null || isIpLiteral()) {
+        if (resolver == null) {
             return super.getSocketAddresses();
         }
         try {
@@ -74,11 +74,6 @@ public List<InetSocketAddress> getSocketAddresses() {
         }
     }
 
-    // If this returns true, it's either an IP literal or a malformed hostname.  But either way, skip lookup via resolver
-    private boolean isIpLiteral() {
-        return getHost().charAt(0) == '[' || Character.digit(getHost().charAt(0), 16) != -1 || (getHost().charAt(0) == ':');
-    }
-
     @Override
     public boolean equals(final Object o) {
         if (this == o) {

driver-core/src/main/com/mongodb/spi/dns/InetAddressResolver.java

@@ -38,6 +38,8 @@ public interface InetAddressResolver {
      * Given the name of a host, returns a list of IP addresses of the requested
      * address family associated with a provided hostname.
      *
+     * <p>The host name can be an IP literal, as with {@link InetAddress#getAllByName(String)}</p>
+     *
      * <p>Implementations are encouraged to implement their own caching policies, as there is
      * no guarantee that the caller will implement a cache.
      *

driver-sync/src/test/functional/com/mongodb/client/AbstractDnsConfigurationTest.java

@@ -21,30 +21,22 @@
 import com.mongodb.MongoException;
 import com.mongodb.MongoSocketException;
 import com.mongodb.ServerAddress;
-import com.mongodb.connection.ServerConnectionState;
 import com.mongodb.connection.ServerDescription;
 import com.mongodb.event.ClusterDescriptionChangedEvent;
 import com.mongodb.event.ClusterListener;
 import com.mongodb.spi.dns.DnsClient;
 import com.mongodb.spi.dns.DnsException;
 import com.mongodb.spi.dns.InetAddressResolver;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.ValueSource;
 
 import java.net.UnknownHostException;
 import java.util.Collections;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeoutException;
 
-import static com.mongodb.ClusterFixture.getConnectionString;
-import static com.mongodb.ClusterFixture.getServerApi;
-import static com.mongodb.ClusterFixture.isStandalone;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assumptions.assumeTrue;
 
 @SuppressWarnings("try")
 public abstract class AbstractDnsConfigurationTest {
@@ -81,41 +73,6 @@ public void clusterDescriptionChanged(final ClusterDescriptionChangedEvent event
         }
     }
 
-    @ParameterizedTest(name = "InetAddressResolver should not be used to resolve IP literal {0}")
-    @ValueSource(strings = {"127.0.0.1", "::1", "[0:0:0:0:0:0:0:1]"})
-    public void testInetAddressResolverDoesNotResolveIpLiteral(final String ipLiteral) throws InterruptedException, ExecutionException,
-            TimeoutException {
-        assumeTrue(isStandalone());
-        assumeTrue(getServerApi() == null);
-
-        // should not be invoked for IP literals
-        InetAddressResolver resolver = host -> {
-            throw new UnknownHostException();
-        };
-
-        CompletableFuture<Boolean> serverConnectedFuture = new CompletableFuture<>();
-        MongoClientSettings settings = MongoClientSettings.builder()
-                .applyConnectionString(getConnectionString())
-                .applyToClusterSettings(builder ->
-                        builder.hosts(Collections.singletonList(new ServerAddress(ipLiteral)))
-                                .addClusterListener(new ClusterListener() {
-                                    @Override
-                                    public void clusterDescriptionChanged(final ClusterDescriptionChangedEvent event) {
-                                        ServerDescription serverDescription = event.getNewDescription().getServerDescriptions().get(0);
-                                        // If the resolver that throws an exception is invoked, the state will not be CONNECTED
-                                        if (serverDescription.getState() == ServerConnectionState.CONNECTED) {
-                                            serverConnectedFuture.complete(true);
-                                        }
-                                    }
-                                }))
-                .inetAddressResolver(resolver)
-                .build();
-
-        try (MongoClient ignored = createMongoClient(settings)) {
-            assertTrue(serverConnectedFuture.get(1, SECONDS));
-        }
-    }
-
     @Test
     public void testDnsClientConfiguration() throws InterruptedException, ExecutionException, TimeoutException {
         DnsException exception = new DnsException("", new Exception());