test/functional/example_test.py

   1 #!/usr/bin/env python3
   2 # Copyright (c) 2017 The Bitcoin Core developers
   3 # Distributed under the MIT software license, see the accompanying
   4 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5 """An example functional test
   6
   7 The module-level docstring should include a high-level description of
   8 what the test is doing. It's the first thing people see when they open
   9 the file and should give the reader information about *what* the test
  10 is testing and *how* it's being tested
  11 """
  12 # Imports should be in PEP8 ordering (std library first, then third party
  13 # libraries then local imports).
  14 from collections import defaultdict
  15
  16 # Avoid wildcard * imports if possible
  17 from test_framework.blocktools import (create_block, create_coinbase)
  18 from test_framework.mininode import (
  19     CInv,
  20     P2PInterface,
  21     mininode_lock,
  22     msg_block,
  23     msg_getdata,
  24     network_thread_join,
  25     network_thread_start,
  26 )
  27 from test_framework.test_framework import BitcoinTestFramework
  28 from test_framework.util import (
  29     assert_equal,
  30     connect_nodes,
  31     wait_until,
  32 )
  33
  34 # P2PInterface is a class containing callbacks to be executed when a P2P
  35 # message is received from the node-under-test. Subclass P2PInterface and
  36 # override the on_*() methods if you need custom behaviour.
  37 class BaseNode(P2PInterface):
  38     def __init__(self):
  39         """Initialize the P2PInterface
  40
  41         Used to inialize custom properties for the Node that aren't
  42         included by default in the base class. Be aware that the P2PInterface
  43         base class already stores a counter for each P2P message type and the
  44         last received message of each type, which should be sufficient for the
  45         needs of most tests.
  46
  47         Call super().__init__() first for standard initialization and then
  48         initialize custom properties."""
  49         super().__init__()
  50         # Stores a dictionary of all blocks received
  51         self.block_receive_map = defaultdict(int)
  52
  53     def on_block(self, message):
  54         """Override the standard on_block callback
  55
  56         Store the hash of a received block in the dictionary."""
  57         message.block.calc_sha256()
  58         self.block_receive_map[message.block.sha256] += 1
  59
  60     def on_inv(self, message):
  61         """Override the standard on_inv callback"""
  62         pass
  63
  64 def custom_function():
  65     """Do some custom behaviour
  66
  67     If this function is more generally useful for other tests, consider
  68     moving it to a module in test_framework."""
  69     # self.log.info("running custom_function")  # Oops! Can't run self.log outside the BitcoinTestFramework
  70     pass
  71
  72 class ExampleTest(BitcoinTestFramework):
  73     # Each functional test is a subclass of the BitcoinTestFramework class.
  74
  75     # Override the set_test_params(), add_options(), setup_chain(), setup_network()
  76     # and setup_nodes() methods to customize the test setup as required.
  77
  78     def set_test_params(self):
  79         """Override test parameters for your individual test.
  80
  81         This method must be overridden and num_nodes must be exlicitly set."""
  82         self.setup_clean_chain = True
  83         self.num_nodes = 3
  84         # Use self.extra_args to change command-line arguments for the nodes
  85         self.extra_args = [[], ["-logips"], []]
  86
  87         # self.log.info("I've finished set_test_params")  # Oops! Can't run self.log before run_test()
  88
  89     # Use add_options() to add specific command-line options for your test.
  90     # In practice this is not used very much, since the tests are mostly written
  91     # to be run in automated environments without command-line options.
  92     # def add_options()
  93     #     pass
  94
  95     # Use setup_chain() to customize the node data directories. In practice
  96     # this is not used very much since the default behaviour is almost always
  97     # fine
  98     # def setup_chain():
  99     #     pass
 100
 101     def setup_network(self):
 102         """Setup the test network topology
 103
 104         Often you won't need to override this, since the standard network topology
 105         (linear: node0 <-> node1 <-> node2 <-> ...) is fine for most tests.
 106
 107         If you do override this method, remember to start the nodes, assign
 108         them to self.nodes, connect them and then sync."""
 109
 110         self.setup_nodes()
 111
 112         # In this test, we're not connecting node2 to node0 or node1. Calls to
 113         # sync_all() should not include node2, since we're not expecting it to
 114         # sync.
 115         connect_nodes(self.nodes[0], 1)
 116         self.sync_all([self.nodes[0:1]])
 117
 118     # Use setup_nodes() to customize the node start behaviour (for example if
 119     # you don't want to start all nodes at the start of the test).
 120     # def setup_nodes():
 121     #     pass
 122
 123     def custom_method(self):
 124         """Do some custom behaviour for this test
 125
 126         Define it in a method here because you're going to use it repeatedly.
 127         If you think it's useful in general, consider moving it to the base
 128         BitcoinTestFramework class so other tests can use it."""
 129
 130         self.log.info("Running custom_method")
 131
 132     def run_test(self):
 133         """Main test logic"""
 134
 135         # Create P2P connections to two of the nodes
 136         self.nodes[0].add_p2p_connection(BaseNode())
 137
 138         # Start up network handling in another thread. This needs to be called
 139         # after the P2P connections have been created.
 140         network_thread_start()
 141         # wait_for_verack ensures that the P2P connection is fully up.
 142         self.nodes[0].p2p.wait_for_verack()
 143
 144         # Generating a block on one of the nodes will get us out of IBD
 145         blocks = [int(self.nodes[0].generate(nblocks=1)[0], 16)]
 146         self.sync_all([self.nodes[0:1]])
 147
 148         # Notice above how we called an RPC by calling a method with the same
 149         # name on the node object. Notice also how we used a keyword argument
 150         # to specify a named RPC argument. Neither of those are defined on the
 151         # node object. Instead there's some __getattr__() magic going on under
 152         # the covers to dispatch unrecognised attribute calls to the RPC
 153         # interface.
 154
 155         # Logs are nice. Do plenty of them. They can be used in place of comments for
 156         # breaking the test into sub-sections.
 157         self.log.info("Starting test!")
 158
 159         self.log.info("Calling a custom function")
 160         custom_function()
 161
 162         self.log.info("Calling a custom method")
 163         self.custom_method()
 164
 165         self.log.info("Create some blocks")
 166         self.tip = int(self.nodes[0].getbestblockhash(), 16)
 167         self.block_time = self.nodes[0].getblock(self.nodes[0].getbestblockhash())['time'] + 1
 168
 169         height = 1
 170
 171         for i in range(10):
 172             # Use the mininode and blocktools functionality to manually build a block
 173             # Calling the generate() rpc is easier, but this allows us to exactly
 174             # control the blocks and transactions.
 175             block = create_block(self.tip, create_coinbase(height), self.block_time)
 176             block.solve()
 177             block_message = msg_block(block)
 178             # Send message is used to send a P2P message to the node over our P2PInterface
 179             self.nodes[0].p2p.send_message(block_message)
 180             self.tip = block.sha256
 181             blocks.append(self.tip)
 182             self.block_time += 1
 183             height += 1
 184
 185         self.log.info("Wait for node1 to reach current tip (height 11) using RPC")
 186         self.nodes[1].waitforblockheight(11)
 187
 188         self.log.info("Connect node2 and node1")
 189         connect_nodes(self.nodes[1], 2)
 190
 191         self.log.info("Add P2P connection to node2")
 192         # We can't add additional P2P connections once the network thread has started. Disconnect the connection
 193         # to node0, wait for the network thread to terminate, then connect to node2. This is specific to
 194         # the current implementation of the network thread and may be improved in future.
 195         self.nodes[0].disconnect_p2ps()
 196         network_thread_join()
 197
 198         self.nodes[2].add_p2p_connection(BaseNode())
 199         network_thread_start()
 200         self.nodes[2].p2p.wait_for_verack()
 201
 202         self.log.info("Wait for node2 reach current tip. Test that it has propagated all the blocks to us")
 203
 204         getdata_request = msg_getdata()
 205         for block in blocks:
 206             getdata_request.inv.append(CInv(2, block))
 207         self.nodes[2].p2p.send_message(getdata_request)
 208
 209         # wait_until() will loop until a predicate condition is met. Use it to test properties of the
 210         # P2PInterface objects.
 211         wait_until(lambda: sorted(blocks) == sorted(list(self.nodes[2].p2p.block_receive_map.keys())), timeout=5, lock=mininode_lock)
 212
 213         self.log.info("Check that each block was received only once")
 214         # The network thread uses a global lock on data access to the P2PConnection objects when sending and receiving
 215         # messages. The test thread should acquire the global lock before accessing any P2PConnection data to avoid locking
 216         # and synchronization issues. Note wait_until() acquires this global lock when testing the predicate.
 217         with mininode_lock:
 218             for block in self.nodes[2].p2p.block_receive_map.values():
 219                 assert_equal(block, 1)
 220
 221 if __name__ == '__main__':
 222     ExampleTest().main()