old_contents: #!/usr/bin/env python3
  # Copyright (c) 2018 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test the blocksdir option.
  """
  
  import os
  import shutil
  
  from test_framework.test_framework import BitcoinTestFramework, initialize_datadir
  
  
  class BlocksdirTest(BitcoinTestFramework):
      def set_test_params(self):
          self.setup_clean_chain = True
          self.num_nodes = 1
  
      def run_test(self):
          self.stop_node(0)
          shutil.rmtree(self.nodes[0].datadir)
          initialize_datadir(self.options.tmpdir, 0)
          self.log.info("Starting with nonexistent blocksdir ...")
          blocksdir_path = os.path.join(self.options.tmpdir, 'blocksdir')
          self.nodes[0].assert_start_raises_init_error(["-blocksdir=" + blocksdir_path], 'Error: Specified blocks directory "{}" does not exist.'.format(blocksdir_path))
          os.mkdir(blocksdir_path)
          self.log.info("Starting with existing blocksdir ...")
          self.start_node(0, ["-blocksdir=" + blocksdir_path])
          self.log.info("mining blocks..")
          self.nodes[0].generatetoaddress(10, self.nodes[0].get_deterministic_priv_key().address)
          assert os.path.isfile(os.path.join(blocksdir_path, "regtest", "blocks", "blk00000.dat"))
          assert os.path.isdir(os.path.join(self.nodes[0].datadir, "regtest", "blocks", "index"))
  
  
  if __name__ == '__main__':
      BlocksdirTest().main()
  
new_contents: #!/usr/bin/env python3
  # Copyright (c) 2018 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test the blocksdir option.
  """
  
  import os
  import shutil
  
  from test_framework.test_framework import BitcoinTestFramework, initialize_datadir
  
  
  class BlocksdirTest(BitcoinTestFramework):
      def set_test_params(self):
          self.setup_clean_chain = True
          self.num_nodes = 1
  
      def run_test(self):
          self.stop_node(0)
          assert os.path.isdir(os.path.join(self.nodes[0].datadir, "regtest", "blocks"))
          assert not os.path.isdir(os.path.join(self.nodes[0].datadir, "blocks"))
          shutil.rmtree(self.nodes[0].datadir)
          initialize_datadir(self.options.tmpdir, 0)
          self.log.info("Starting with nonexistent blocksdir ...")
          blocksdir_path = os.path.join(self.options.tmpdir, 'blocksdir')
          self.nodes[0].assert_start_raises_init_error(["-blocksdir=" + blocksdir_path], 'Error: Specified blocks directory "{}" does not exist.'.format(blocksdir_path))
          os.mkdir(blocksdir_path)
          self.log.info("Starting with existing blocksdir ...")
          self.start_node(0, ["-blocksdir=" + blocksdir_path])
          self.log.info("mining blocks..")
          self.nodes[0].generatetoaddress(10, self.nodes[0].get_deterministic_priv_key().address)
          assert os.path.isfile(os.path.join(blocksdir_path, "regtest", "blocks", "blk00000.dat"))
          assert os.path.isdir(os.path.join(self.nodes[0].datadir, "regtest", "blocks", "index"))
  
  
  if __name__ == '__main__':
      BlocksdirTest().main()
  
subject: Improve blocksdir functional test.