text: #!/usr/bin/env python3
  # Copyright (c) 2014-2016 The Bitcoin Core developers
  # Copyright (c) 2017 The Copper Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test the getchaintips RPC.
  
  - introduce a network split
  - work on chains of different lengths
  - join the network together again
  - verify that getchaintips now returns two chain tips.
  """
  
  from test_framework.test_framework import CopperTestFramework
  from test_framework.util import assert_equal
  
  class GetChainTipsTest (CopperTestFramework):
      def set_test_params(self):
          self.num_nodes = 4
  
      def run_test (self):
          tips = self.nodes[0].getchaintips ()
          assert_equal (len (tips), 1)
          assert_equal (tips[0]['branchlen'], 0)
          assert_equal (tips[0]['height'], 200)
          assert_equal (tips[0]['status'], 'active')
  
          # Split the network and build two chains of different lengths.
          self.split_network ()
          self.nodes[0].generate(10)
          self.nodes[2].generate(20)
          self.sync_all([self.nodes[:2], self.nodes[2:]])
  
          tips = self.nodes[1].getchaintips ()
          assert_equal (len (tips), 1)
          shortTip = tips[0]
          assert_equal (shortTip['branchlen'], 0)
          assert_equal (shortTip['height'], 210)
          assert_equal (tips[0]['status'], 'active')
  
          tips = self.nodes[3].getchaintips ()
          assert_equal (len (tips), 1)
          longTip = tips[0]
          assert_equal (longTip['branchlen'], 0)
          assert_equal (longTip['height'], 220)
          assert_equal (tips[0]['status'], 'active')
  
          # Join the network halves and check that we now have two tips
          # (at least at the nodes that previously had the short chain).
          self.join_network ()
  
          tips = self.nodes[0].getchaintips ()
          assert_equal (len (tips), 2)
          assert_equal (tips[0], longTip)
  
          assert_equal (tips[1]['branchlen'], 10)
          assert_equal (tips[1]['status'], 'valid-fork')
          tips[1]['branchlen'] = 0
          tips[1]['status'] = 'active'
          assert_equal (tips[1], shortTip)
  
  if __name__ == '__main__':
      GetChainTipsTest ().main ()
  