test: Creating dummy spanner instance for ITInstanceAdminTest (#1977)

test: Updated ITInstanceAdminTest to run in a parallel environment with a new dummy instance

Author: gauravpurohit06

google-cloud-spanner/src/test/java/com/google/cloud/spanner/IntegrationTestEnv.java

@@ -58,8 +58,17 @@ public class IntegrationTestEnv extends ExternalResource {
   private InstanceAdminClient instanceAdminClient;
   private DatabaseAdminClient databaseAdminClient;
   private boolean isOwnedInstance;
+  private final boolean alwaysCreateNewInstance;
   private RemoteSpannerHelper testHelper;
 
+  public IntegrationTestEnv() {
+    this(false);
+  }
+
+  public IntegrationTestEnv(final boolean alwaysCreateNewInstance) {
+    this.alwaysCreateNewInstance = alwaysCreateNewInstance;
+  }
+
   public RemoteSpannerHelper getTestHelper() {
     checkInitialized();
     return testHelper;
@@ -84,7 +93,7 @@ protected void before() throws Throwable {
     SpannerOptions options = config.spannerOptions();
     String instanceProperty = System.getProperty(TEST_INSTANCE_PROPERTY, "");
     InstanceId instanceId;
-    if (!instanceProperty.isEmpty()) {
+    if (!instanceProperty.isEmpty() && !alwaysCreateNewInstance) {
       instanceId = InstanceId.of(instanceProperty);
       isOwnedInstance = false;
       logger.log(Level.INFO, "Using existing test instance: {0}", instanceId);

google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITInstanceAdminTest.java

@@ -27,13 +27,13 @@
 import com.google.cloud.spanner.InstanceInfo;
 import com.google.cloud.spanner.IntegrationTestEnv;
 import com.google.cloud.spanner.Options;
-import com.google.cloud.spanner.SerialIntegrationTest;
+import com.google.cloud.spanner.ParallelIntegrationTest;
 import com.google.common.collect.Iterators;
 import com.google.spanner.admin.instance.v1.UpdateInstanceMetadata;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
-import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -42,14 +42,15 @@
 import org.junit.runners.JUnit4;
 
 /** Integration tests for {@link com.google.cloud.spanner.InstanceAdminClient}. */
-@Category(SerialIntegrationTest.class)
+@Category(ParallelIntegrationTest.class)
 @RunWith(JUnit4.class)
 public class ITInstanceAdminTest {
-  @ClassRule public static IntegrationTestEnv env = new IntegrationTestEnv();
-  InstanceAdminClient instanceClient;
 
-  @Before
-  public void setUp() {
+  @ClassRule public static IntegrationTestEnv env = new IntegrationTestEnv(true);
+  static InstanceAdminClient instanceClient;
+
+  @BeforeClass
+  public static void setUp() {
     instanceClient = env.getTestHelper().getClient().getInstanceAdminClient();
   }
 
@@ -78,6 +79,8 @@ public void instanceConfigLeaderOptions() {
 
   @Test
   public void listInstances() {
+    assumeFalse("The emulator does not support filtering on instances", isUsingEmulator());
+
     Instance instance =
         Iterators.getOnlyElement(
             instanceClient