feat: expose leader options in instance config

Exposes the list of leader options for an instance from an instance
config.

@@ -16,6 +16,9 @@
 
 package com.google.cloud.spanner;
 
+import java.util.Collections;
+import java.util.List;
+
 /**
 * Represents a Cloud Spanner instance config.{@code InstanceConfig} adds a layer of service related
 * functionality over {@code InstanceConfigInfo}.
@@ -25,7 +28,15 @@ public class InstanceConfig extends InstanceConfigInfo {
 private final InstanceAdminClient client;
 
 public InstanceConfig(InstanceConfigId id, String displayName, InstanceAdminClient client) {
-super(id, displayName);
+this(id, displayName, Collections.emptyList(), client);
+}
+
+public InstanceConfig(
+InstanceConfigId id,
+String displayName,
+List<String> leaderOptions,
+InstanceAdminClient client) {
+super(id, displayName, leaderOptions);
 this.client = client;
 }
 
@@ -36,6 +47,10 @@ public InstanceConfig reload() {
 
 static InstanceConfig fromProto(
 com.google.spanner.admin.instance.v1.InstanceConfig proto, InstanceAdminClient client) {
-return new InstanceConfig(InstanceConfigId.of(proto.getName()), proto.getDisplayName(), client);
+return new InstanceConfig(
+InstanceConfigId.of(proto.getName()),
+proto.getDisplayName(),
+proto.getLeaderOptionsList(),
+client);
 }
 }

@@ -45,6 +45,7 @@
 import io.grpc.inprocess.InProcessServerBuilder;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -353,8 +354,13 @@ public void getInstanceConfigTest() {
 for (int i = 0; i < 2; i++) {
 InstanceConfigName name2 = InstanceConfigName.of(PROJECT, "INSTANCE_CONFIG");
 String displayName = "displayName1615086568";
+List<String> leaderOptions = Arrays.asList("leader option 1", "leader option 2");
 InstanceConfig expectedResponse =
-InstanceConfig.newBuilder().setName(name2.toString()).setDisplayName(displayName).build();
+InstanceConfig.newBuilder()
+.setName(name2.toString())
+.setDisplayName(displayName)
+.addAllLeaderOptions(leaderOptions)
+.build();
 if (exceptionAtCall == 0) {
 mockInstanceAdmin.addException(exception);
 }
@@ -368,6 +374,7 @@ public void getInstanceConfigTest() {
 client.getInstanceConfig(name.toString());
 
 Assert.assertEquals(displayName, actualResponse.getDisplayName());
+Assert.assertEquals(leaderOptions, actualResponse.getLeaderOptions());
 List<AbstractMessage> actualRequests = mockInstanceAdmin.getRequests();
 Assert.assertEquals(i + 1, actualRequests.size());
 }

@@ -0,0 +1,70 @@
+/*
+* Copyright 2021 Google LLC
+*
+* 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 com.google.cloud.spanner;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+
+import java.util.Arrays;
+import org.junit.Before;
+import org.junit.Test;
+
+public class InstanceConfigTest {
+
+private InstanceAdminClient client;
+
+@Before
+public void setUp() {
+client = mock(InstanceAdminClient.class);
+}
+
+@Test
+public void testInstanceConfigFromProtoWithoutLeaderOptions() {
+final InstanceConfig instanceConfig =
+InstanceConfig.fromProto(
+com.google.spanner.admin.instance.v1.InstanceConfig.newBuilder()
+.setDisplayName("Display Name")
+.setName("projects/my-project/instanceConfigs/my-instance-config")
+.build(),
+client);
+
+assertEquals(
+new InstanceConfig(
+InstanceConfigId.of("my-project", "my-instance-config"), "Display Name", client),
+instanceConfig);
+}
+
+@Test
+public void testInstanceConfigFromProtoWithLeaderOptions() {
+final InstanceConfig instanceConfig =
+InstanceConfig.fromProto(
+com.google.spanner.admin.instance.v1.InstanceConfig.newBuilder()
+.setDisplayName("Display Name")
+.setName("projects/my-project/instanceConfigs/my-instance-config")
+.addAllLeaderOptions(Arrays.asList("Leader Option 1", "Leader Option 2"))
+.build(),
+client);
+
+assertEquals(
+new InstanceConfig(
+InstanceConfigId.of("my-project", "my-instance-config"),
+"Display Name",
+Arrays.asList("Leader Option 1", "Leader Option 2"),
+client),
+instanceConfig);
+}
+}