code: /*
   * Copyright (c) 2022 Airbyte, Inc., all rights reserved.
   */
  
  package io.airbyte.db;
  
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import com.google.common.collect.ImmutableMap;
  import io.airbyte.commons.io.IOs;
  import io.airbyte.commons.json.Jsons;
  import io.airbyte.commons.string.Strings;
  import io.airbyte.db.factory.DataSourceFactory;
  import io.airbyte.db.factory.DatabaseDriver;
  import io.airbyte.db.jdbc.DefaultJdbcDatabase;
  import io.airbyte.db.jdbc.JdbcDatabase;
  import io.airbyte.db.jdbc.JdbcUtils;
  import io.airbyte.test.utils.PostgreSQLContainerHelper;
  import java.sql.SQLException;
  import javax.sql.DataSource;
  import org.junit.jupiter.api.BeforeAll;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  import org.testcontainers.containers.PostgreSQLContainer;
  import org.testcontainers.utility.MountableFile;
  
  class PostgresUtilsTest {
  
    private static PostgreSQLContainer<?> PSQL_DB;
  
    private DataSource dataSource;
  
    @BeforeAll
    static void init() {
      PSQL_DB = new PostgreSQLContainer<>("postgres:13-alpine");
      PSQL_DB.start();
  
    }
  
    @BeforeEach
    void setup() throws Exception {
      final String dbName = Strings.addRandomSuffix("db", "_", 10);
  
      final JsonNode config = getConfig(PSQL_DB, dbName);
  
      final String initScriptName = "init_" + dbName.concat(".sql");
      final String tmpFilePath = IOs.writeFileToRandomTmpDir(initScriptName, "CREATE DATABASE " + dbName + ";");
      PostgreSQLContainerHelper.runSqlScript(MountableFile.forHostPath(tmpFilePath), PSQL_DB);
  
      dataSource = DataSourceFactory.create(
          config.get(JdbcUtils.USERNAME_KEY).asText(),
          config.get(JdbcUtils.PASSWORD_KEY).asText(),
          DatabaseDriver.POSTGRESQL.getDriverClassName(),
          String.format(DatabaseDriver.POSTGRESQL.getUrlFormatString(),
              config.get(JdbcUtils.HOST_KEY).asText(),
              config.get(JdbcUtils.PORT_KEY).asInt(),
              config.get(JdbcUtils.DATABASE_KEY).asText()));
  
      final JdbcDatabase defaultJdbcDatabase = new DefaultJdbcDatabase(dataSource);
  
      defaultJdbcDatabase.execute(connection -> {
        connection.createStatement().execute("CREATE TABLE id_and_name(id INTEGER, name VARCHAR(200));");
        connection.createStatement().execute("INSERT INTO id_and_name (id, name) VALUES (1,'picard'),  (2, 'crusher'), (3, 'vash');");
      });
    }
  
    private JsonNode getConfig(final PostgreSQLContainer<?> psqlDb, final String dbName) {
      return Jsons.jsonNode(ImmutableMap.builder()
          .put(JdbcUtils.HOST_KEY, psqlDb.getHost())
          .put(JdbcUtils.PORT_KEY, psqlDb.getFirstMappedPort())
          .put(JdbcUtils.DATABASE_KEY, dbName)
          .put(JdbcUtils.USERNAME_KEY, psqlDb.getUsername())
          .put(JdbcUtils.PASSWORD_KEY, psqlDb.getPassword())
          .build());
    }
  
    @Test
    void testGetLsn() throws SQLException {
      final JdbcDatabase database = new DefaultJdbcDatabase(dataSource);
  
      final PgLsn lsn1 = PostgresUtils.getLsn(database);
      assertNotNull(lsn1);
      assertTrue(lsn1.asLong() > 0);
  
      database.execute(connection -> {
        connection.createStatement().execute("INSERT INTO id_and_name (id, name) VALUES (1,'picard'),  (2, 'crusher'), (3, 'vash');");
      });
  
      final PgLsn lsn2 = PostgresUtils.getLsn(database);
      assertNotNull(lsn2);
      assertTrue(lsn2.asLong() > 0);
  
      assertTrue(lsn1.compareTo(lsn2) < 0, "returned lsns are not ascending.");
    }
  
  }
  