up method

Implementation

@override
Future up() async {
  await _init();
  var r = await connection.execute('SELECT path from migrations;');
  var existing = r.expand((x) => x).cast<String>();
  var toRun = <String>[];

  migrations.forEach((k, v) {
    if (!existing.contains(k)) toRun.add(k);
  });

  if (toRun.isNotEmpty) {
    var r = await connection.execute('SELECT MAX(batch) from migrations;');
    var curBatch = (r[0][0] ?? 0) as int;
    var batch = curBatch + 1;

    for (var k in toRun) {
      var migration = migrations[k]!;
      var schema = PostgresSchema();
      migration.up(schema);

      var result = await schema
          .run(connection)
          .then((_) {
            return connection.runTx((ctx) async {
              var result = await ctx.execute(
                "INSERT INTO MIGRATIONS (batch, path) VALUES ($batch, '$k')",
              );

              return result.affectedRows;
            });
          })
          .catchError((e) {
            _log.severe('Failed to insert into "migrations" table.');
            return -1;
          });
      if (result > 0) {
        _log.info('Inserted "$k" into "migrations" table.');
      }
    }
  } else {
    _log.warning('Nothing to add into "migrations" table.');
  }
}