test: fix flaky tests for FGAC (#1981)

* test: fix flaky tests for FGAC

* fix lint

* incorporate requested changes

* refactoring afterClass

Author: rahul2393

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

@@ -25,6 +25,7 @@
 import com.google.cloud.spanner.Database;
 import com.google.cloud.spanner.DatabaseAdminClient;
 import com.google.cloud.spanner.DatabaseClient;
+import com.google.cloud.spanner.DatabaseId;
 import com.google.cloud.spanner.ErrorCode;
 import com.google.cloud.spanner.IntegrationTestEnv;
 import com.google.cloud.spanner.ParallelIntegrationTest;
@@ -35,9 +36,12 @@
 import com.google.cloud.spanner.Statement;
 import com.google.cloud.spanner.testing.RemoteSpannerHelper;
 import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.concurrent.TimeUnit;
-import org.junit.Before;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
@@ -49,14 +53,30 @@
 @RunWith(JUnit4.class)
 public class ITDatabaseRolePermissionTest {
   @ClassRule public static IntegrationTestEnv env = new IntegrationTestEnv();
-  private DatabaseAdminClient dbAdminClient;
-  private RemoteSpannerHelper testHelper;
+  private static DatabaseAdminClient dbAdminClient;
+  private static RemoteSpannerHelper testHelper;
 
-  @Before
-  public void setUp() {
+  private static List<DatabaseId> databasesToDrop;
+
+  @BeforeClass
+  public static void setUp() {
     assumeFalse("Emulator does not support database roles", isUsingEmulator());
     testHelper = env.getTestHelper();
     dbAdminClient = testHelper.getClient().getDatabaseAdminClient();
+    databasesToDrop = new ArrayList<>();
+  }
+
+  @AfterClass
+  public static void cleanup() throws Exception {
+    if (databasesToDrop != null) {
+      for (DatabaseId id : databasesToDrop) {
+        try {
+          dbAdminClient.dropDatabase(id.getInstanceId().getInstance(), id.getDatabase());
+        } catch (Exception e) {
+          System.err.println("Failed to drop database " + id + ", skipping...: " + e.getMessage());
+        }
+      }
+    }
   }
 
   @Test
@@ -84,7 +104,6 @@ public void grantAndRevokeDatabaseRolePermissions() throws Exception {
 
     Spanner spanner = options.getService();
     DatabaseClient dbClient = spanner.getDatabaseClient(createdDatabase.getId());
-    DatabaseAdminClient dbAdminClient = spanner.getDatabaseAdminClient();
 
     // Test SELECT permissions to role dbRoleParent on table T.
     // Query using dbRoleParent should return result.
@@ -103,7 +122,7 @@ public void grantAndRevokeDatabaseRolePermissions() throws Exception {
     dbAdminClient
         .updateDatabaseDdl(
             instanceId, databaseId, Arrays.asList(revokeSelectOnTableFromParent), null)
-        .get();
+        .get(5, TimeUnit.MINUTES);
 
     // Test SELECT permissions to role dbRoleParent on table T.
     // Query using dbRoleParent should return PermissionDeniedException.
@@ -118,7 +137,8 @@ public void grantAndRevokeDatabaseRolePermissions() throws Exception {
     final String dropRoleParent = String.format("DROP ROLE %s", dbRoleParent);
     dbAdminClient
         .updateDatabaseDdl(instanceId, databaseId, Arrays.asList(dropTableT, dropRoleParent), null)
-        .get();
+        .get(5, TimeUnit.MINUTES);
+    databasesToDrop.add(createdDatabase.getId());
   }
 
   @Test
@@ -141,7 +161,6 @@ public void roleWithNoPermissions() throws Exception {
 
     Spanner spanner = options.getService();
     DatabaseClient dbClient = spanner.getDatabaseClient(createdDatabase.getId());
-    DatabaseAdminClient dbAdminClient = spanner.getDatabaseAdminClient();
 
     // Test SELECT permissions to role dbRoleOrphan on table T.
     // Query using dbRoleOrphan should return PermissionDeniedException.
@@ -156,6 +175,7 @@ public void roleWithNoPermissions() throws Exception {
     final String dropRoleParent = String.format("DROP ROLE %s", dbRoleOrphan);
     dbAdminClient
         .updateDatabaseDdl(instanceId, databaseId, Arrays.asList(dropTableT, dropRoleParent), null)
-        .get();
+        .get(5, TimeUnit.MINUTES);
+    databasesToDrop.add(createdDatabase.getId());
   }
 }