text: #!/usr/bin/env python3
  # Copyright (c) 2014-2021 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 -alertnotify, -blocknotify and -walletnotify options."""
  import os
  
  from test_framework.address import ADDRESS_BCRT1_UNSPENDABLE
  from test_framework.descriptors import descsum_create
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import (
      assert_equal,
  )
  
  # Linux allow all characters other than \x00
  # Windows disallow control characters (0-31) and /\?%:|"<>
  FILE_CHAR_START = 32 if os.name == 'nt' else 1
  FILE_CHAR_END = 128
  FILE_CHARS_DISALLOWED = '/\\?%*:|"<>' if os.name == 'nt' else '/'
  UNCONFIRMED_HASH_STRING = 'unconfirmed'
  
  def notify_outputname(walletname, txid):
      return txid if os.name == 'nt' else f'{walletname}_{txid}'
  
  
  class NotificationsTest(BitcoinTestFramework):
      def set_test_params(self):
          self.num_nodes = 2
          self.setup_clean_chain = True
          # The experimental syscall sandbox feature (-sandbox) is not compatible with -alertnotify,
          # -blocknotify or -walletnotify (which all invoke execve).
          self.disable_syscall_sandbox = True
  
      def setup_network(self):
          self.wallet = ''.join(chr(i) for i in range(FILE_CHAR_START, FILE_CHAR_END) if chr(i) not in FILE_CHARS_DISALLOWED)
          self.alertnotify_dir = os.path.join(self.options.tmpdir, "alertnotify")
          self.blocknotify_dir = os.path.join(self.options.tmpdir, "blocknotify")
          self.walletnotify_dir = os.path.join(self.options.tmpdir, "walletnotify")
          os.mkdir(self.alertnotify_dir)
          os.mkdir(self.blocknotify_dir)
          os.mkdir(self.walletnotify_dir)
  
          # -alertnotify and -blocknotify on node0, walletnotify on node1
          self.extra_args = [[
              f"-alertnotify=echo > {os.path.join(self.alertnotify_dir, '%s')}",
              f"-blocknotify=echo > {os.path.join(self.blocknotify_dir, '%s')}",
          ], [
              f"-walletnotify=echo %h_%b > {os.path.join(self.walletnotify_dir, notify_outputname('%w', '%s'))}",
          ]]
          self.wallet_names = [self.default_wallet_name, self.wallet]
          super().setup_network()
  
      def run_test(self):
          if self.is_wallet_compiled():
              # Setup the descriptors to be imported to the wallet
              seed = "cTdGmKFWpbvpKQ7ejrdzqYT2hhjyb3GPHnLAK7wdi5Em67YLwSm9"
              xpriv = "tprv8ZgxMBicQKsPfHCsTwkiM1KT56RXbGGTqvc2hgqzycpwbHqqpcajQeMRZoBD35kW4RtyCemu6j34Ku5DEspmgjKdt2qe4SvRch5Kk8B8A2v"
              desc_imports = [{
                  "desc": descsum_create(f"wpkh({xpriv}/0/*)"),
                  "timestamp": 0,
                  "active": True,
                  "keypool": True,
              },{
                  "desc": descsum_create(f"wpkh({xpriv}/1/*)"),
                  "timestamp": 0,
                  "active": True,
                  "keypool": True,
                  "internal": True,
              }]
              # Make the wallets and import the descriptors
              # Ensures that node 0 and node 1 share the same wallet for the conflicting transaction tests below.
              for i, name in enumerate(self.wallet_names):
                  self.nodes[i].createwallet(wallet_name=name, descriptors=self.options.descriptors, blank=True, load_on_startup=True)
                  if self.options.descriptors:
                      self.nodes[i].importdescriptors(desc_imports)
                  else:
                      self.nodes[i].sethdseed(True, seed)
  
          self.log.info("test -blocknotify")
          block_count = 10
          blocks = self.generatetoaddress(self.nodes[1], block_count, self.nodes[1].getnewaddress() if self.is_wallet_compiled() else ADDRESS_BCRT1_UNSPENDABLE)
  
          # wait at most 10 seconds for expected number of files before reading the content
          self.wait_until(lambda: len(os.listdir(self.blocknotify_dir)) == block_count, timeout=10)
  
          # directory content should equal the generated blocks hashes
          assert_equal(sorted(blocks), sorted(os.listdir(self.blocknotify_dir)))
  
          if self.is_wallet_compiled():
              self.log.info("test -walletnotify")
              # wait at most 10 seconds for expected number of files before reading the content
              self.wait_until(lambda: len(os.listdir(self.walletnotify_dir)) == block_count, timeout=10)
  
              # directory content should equal the generated transaction hashes
              tx_details = list(map(lambda t: (t['txid'], t['blockheight'], t['blockhash']), self.nodes[1].listtransactions("*", block_count)))
              self.expect_wallet_notify(tx_details)
  
              self.log.info("test -walletnotify after rescan")
              # rescan to force wallet notifications
              self.nodes[1].rescanblockchain()
              self.wait_until(lambda: len(os.listdir(self.walletnotify_dir)) == block_count, timeout=10)
  
              self.connect_nodes(0, 1)
  
              # directory content should equal the generated transaction hashes
              tx_details = list(map(lambda t: (t['txid'], t['blockheight'], t['blockhash']), self.nodes[1].listtransactions("*", block_count)))
              self.expect_wallet_notify(tx_details)
  
              # Conflicting transactions tests.
              # Generate spends from node 0, and check notifications
              # triggered by node 1
              self.log.info("test -walletnotify with conflicting transactions")
              self.nodes[0].rescanblockchain()
              self.generatetoaddress(self.nodes[0], 100, ADDRESS_BCRT1_UNSPENDABLE)
  
              # Generate transaction on node 0, sync mempools, and check for
              # notification on node 1.
              tx1 = self.nodes[0].sendtoaddress(address=ADDRESS_BCRT1_UNSPENDABLE, amount=1, replaceable=True)
              assert_equal(tx1 in self.nodes[0].getrawmempool(), True)
              self.sync_mempools()
              self.expect_wallet_notify([(tx1, -1, UNCONFIRMED_HASH_STRING)])
  
              # Generate bump transaction, sync mempools, and check for bump1
              # notification. In the future, per
              # https://github.com/bitcoin/bitcoin/pull/9371, it might be better
              # to have notifications for both tx1 and bump1.
              bump1 = self.nodes[0].bumpfee(tx1)["txid"]
              assert_equal(bump1 in self.nodes[0].getrawmempool(), True)
              self.sync_mempools()
              self.expect_wallet_notify([(bump1, -1, UNCONFIRMED_HASH_STRING)])
  
              # Add bump1 transaction to new block, checking for a notification
              # and the correct number of confirmations.
              blockhash1 = self.generatetoaddress(self.nodes[0], 1, ADDRESS_BCRT1_UNSPENDABLE)[0]
              blockheight1 = self.nodes[0].getblockcount()
              self.sync_blocks()
              self.expect_wallet_notify([(bump1, blockheight1, blockhash1)])
              assert_equal(self.nodes[1].gettransaction(bump1)["confirmations"], 1)
  
              # Generate a second transaction to be bumped.
              tx2 = self.nodes[0].sendtoaddress(address=ADDRESS_BCRT1_UNSPENDABLE, amount=1, replaceable=True)
              assert_equal(tx2 in self.nodes[0].getrawmempool(), True)
              self.sync_mempools()
              self.expect_wallet_notify([(tx2, -1, UNCONFIRMED_HASH_STRING)])
  
              # Bump tx2 as bump2 and generate a block on node 0 while
              # disconnected, then reconnect and check for notifications on node 1
              # about newly confirmed bump2 and newly conflicted tx2.
              self.disconnect_nodes(0, 1)
              bump2 = self.nodes[0].bumpfee(tx2)["txid"]
              blockhash2 = self.generatetoaddress(self.nodes[0], 1, ADDRESS_BCRT1_UNSPENDABLE, sync_fun=self.no_op)[0]
              blockheight2 = self.nodes[0].getblockcount()
              assert_equal(self.nodes[0].gettransaction(bump2)["confirmations"], 1)
              assert_equal(tx2 in self.nodes[1].getrawmempool(), True)
              self.connect_nodes(0, 1)
              self.sync_blocks()
              self.expect_wallet_notify([(bump2, blockheight2, blockhash2), (tx2, -1, UNCONFIRMED_HASH_STRING)])
              assert_equal(self.nodes[1].gettransaction(bump2)["confirmations"], 1)
  
          # TODO: add test for `-alertnotify` large fork notifications
  
      def expect_wallet_notify(self, tx_details):
          self.wait_until(lambda: len(os.listdir(self.walletnotify_dir)) >= len(tx_details), timeout=10)
          # Should have no more and no less files than expected
          assert_equal(sorted(notify_outputname(self.wallet, tx_id) for tx_id, _, _ in tx_details), sorted(os.listdir(self.walletnotify_dir)))
          # Should now verify contents of each file
          for tx_id, blockheight, blockhash in tx_details:
              fname = os.path.join(self.walletnotify_dir, notify_outputname(self.wallet, tx_id))
              # Wait for the cached writes to hit storage
              self.wait_until(lambda: os.path.getsize(fname) > 0, timeout=10)
              with open(fname, 'rt', encoding='utf-8') as f:
                  text = f.read()
                  # Universal newline ensures '\n' on 'nt'
                  assert_equal(text[-1], '\n')
                  text = text[:-1]
                  if os.name == 'nt':
                      # On Windows, echo as above will append a whitespace
                      assert_equal(text[-1], ' ')
                      text = text[:-1]
                  expected = f'{str(blockheight)}_{blockhash}'
                  assert_equal(text, expected)
  
          for tx_file in os.listdir(self.walletnotify_dir):
              os.remove(os.path.join(self.walletnotify_dir, tx_file))
  
  
  if __name__ == '__main__':
      NotificationsTest().main()
  