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     NetworkThread,
  21     NodeConn,
  22     NodeConnCB,
  23     mininode_lock,
  24     msg_block,
  25     msg_getdata,
  26     wait_until,
  27 )
  28 from test_framework.test_framework import BitcoinTestFramework
  29 from test_framework.util import (
  30     assert_equal,
  31     connect_nodes,
  32     p2p_port,
  33 )
  34
  35 # NodeConnCB is a class containing callbacks to be executed when a P2P
  36 # message is received from the node-under-test. Subclass NodeConnCB and
  37 # override the on_*() methods if you need custom behaviour.
  38 class BaseNode(NodeConnCB):
  39     def __init__(self):
  40         """Initialize the NodeConnCB
  41
  42         Used to inialize custom properties for the Node that aren't
  43         included by default in the base class. Be aware that the NodeConnCB
  44         base class already stores a counter for each P2P message type and the
  45         last received message of each type, which should be sufficient for the
  46         needs of most tests.
  47
  48         Call super().__init__() first for standard initialization and then
  49         initialize custom properties."""
  50         super().__init__()
  51         # Stores a dictionary of all blocks received
  52         self.block_receive_map = defaultdict(int)
  53
  54     def on_block(self, conn, message):
  55         """Override the standard on_block callback
  56
  57         Store the hash of a received block in the dictionary."""
  58         message.block.calc_sha256()
  59         self.block_receive_map[message.block.sha256] += 1
  60
  61 def custom_function():
  62     """Do some custom behaviour
  63
  64     If this function is more generally useful for other tests, consider
  65     moving it to a module in test_framework."""
  66     # self.log.info("running custom_function")  # Oops! Can't run self.log outside the BitcoinTestFramework
  67     pass
  68
  69 class ExampleTest(BitcoinTestFramework):
  70     # Each functional test is a subclass of the BitcoinTestFramework class.
  71
  72     # Override the __init__(), add_options(), setup_chain(), setup_network()
  73     # and setup_nodes() methods to customize the test setup as required.
  74
  75     def __init__(self):
  76         """Initialize the test
  77
  78         Call super().__init__() first, and then override any test parameters
  79         for your individual test."""
  80         super().__init__()
  81         self.setup_clean_chain = True
  82         self.num_nodes = 3
  83         # Use self.extra_args to change command-line arguments for the nodes
  84         self.extra_args = [[], ["-logips"], []]
  85
  86         # self.log.info("I've finished __init__")  # Oops! Can't run self.log before run_test()
  87
  88     # Use add_options() to add specific command-line options for your test.
  89     # In practice this is not used very much, since the tests are mostly written
  90     # to be run in automated environments without command-line options.
  91     # def add_options()
  92     #     pass
  93
  94     # Use setup_chain() to customize the node data directories. In practice
  95     # this is not used very much since the default behaviour is almost always
  96     # fine
  97     # def setup_chain():
  98     #     pass
  99
 100     def setup_network(self):
 101         """Setup the test network topology
 102
 103         Often you won't need to override this, since the standard network topology
 104         (linear: node0 <-> node1 <-> node2 <-> ...) is fine for most tests.
 105
 106         If you do override this method, remember to start the nodes, assign
 107         them to self.nodes, connect them and then sync."""
 108
 109         self.setup_nodes()
 110
 111         # In this test, we're not connecting node2 to node0 or node1. Calls to
 112         # sync_all() should not include node2, since we're not expecting it to
 113         # sync.
 114         connect_nodes(self.nodes[0], 1)
 115         self.sync_all([self.nodes[0:1]])
 116
 117     # Use setup_nodes() to customize the node start behaviour (for example if
 118     # you don't want to start all nodes at the start of the test).
 119     # def setup_nodes():
 120     #     pass
 121
 122     def custom_method(self):
 123         """Do some custom behaviour for this test
 124
 125         Define it in a method here because you're going to use it repeatedly.
 126         If you think it's useful in general, consider moving it to the base
 127         BitcoinTestFramework class so other tests can use it."""
 128
 129         self.log.info("Running custom_method")
 130
 131     def run_test(self):
 132         """Main test logic"""
 133
 134         # Create a P2P connection to one of the nodes
 135         node0 = BaseNode()
 136         connections = []
 137         connections.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], node0))
 138         node0.add_connection(connections[0])
 139
 140         # Start up network handling in another thread. This needs to be called
 141         # after the P2P connections have been created.
 142         NetworkThread().start()
 143         # wait_for_verack ensures that the P2P connection is fully up.
 144         node0.wait_for_verack()
 145
 146         # Generating a block on one of the nodes will get us out of IBD
 147         blocks = [int(self.nodes[0].generate(nblocks=1)[0], 16)]
 148         self.sync_all([self.nodes[0:1]])
 149
 150         # Notice above how we called an RPC by calling a method with the same
 151         # name on the node object. Notice also how we used a keyword argument
 152         # to specify a named RPC argument. Neither of those are defined on the
 153         # node object. Instead there's some __getattr__() magic going on under
 154         # the covers to dispatch unrecognised attribute calls to the RPC
 155         # interface.
 156
 157         # Logs are nice. Do plenty of them. They can be used in place of comments for
 158         # breaking the test into sub-sections.
 159         self.log.info("Starting test!")
 160
 161         self.log.info("Calling a custom function")
 162         custom_function()
 163
 164         self.log.info("Calling a custom method")
 165         self.custom_method()
 166
 167         self.log.info("Create some blocks")
 168         self.tip = int(self.nodes[0].getbestblockhash(), 16)
 169         self.block_time = self.nodes[0].getblock(self.nodes[0].getbestblockhash())['time'] + 1
 170
 171         height = 1
 172
 173         for i in range(10):
 174             # Use the mininode and blocktools functionality to manually build a block
 175             # Calling the generate() rpc is easier, but this allows us to exactly
 176             # control the blocks and transactions.
 177             block = create_block(self.tip, create_coinbase(height), self.block_time)
 178             block.solve()
 179             block_message = msg_block(block)
 180             # Send message is used to send a P2P message to the node over our NodeConn connection
 181             node0.send_message(block_message)
 182             self.tip = block.sha256
 183             blocks.append(self.tip)
 184             self.block_time += 1
 185             height += 1
 186
 187         self.log.info("Wait for node1 to reach current tip (height 11) using RPC")
 188         self.nodes[1].waitforblockheight(11)
 189
 190         self.log.info("Connect node2 and node1")
 191         connect_nodes(self.nodes[1], 2)
 192
 193         self.log.info("Add P2P connection to node2")
 194         node2 = BaseNode()
 195         connections.append(NodeConn('127.0.0.1', p2p_port(2), self.nodes[2], node2))
 196         node2.add_connection(connections[1])
 197         node2.wait_for_verack()
 198
 199         self.log.info("Wait for node2 reach current tip. Test that it has propogated all the blocks to us")
 200
 201         for block in blocks:
 202             getdata_request = msg_getdata()
 203             getdata_request.inv.append(CInv(2, block))
 204             node2.send_message(getdata_request)
 205
 206         # wait_until() will loop until a predicate condition is met. Use it to test properties of the
 207         # NodeConnCB objects.
 208         assert wait_until(lambda: sorted(blocks) == sorted(list(node2.block_receive_map.keys())), timeout=5)
 209
 210         self.log.info("Check that each block was received only once")
 211         # The network thread uses a global lock on data access to the NodeConn objects when sending and receiving
 212         # messages. The test thread should acquire the global lock before accessing any NodeConn data to avoid locking
 213         # and synchronization issues. Note wait_until() acquires this global lock when testing the predicate.
 214         with mininode_lock:
 215             for block in node2.block_receive_map.values():
 216                 assert_equal(block, 1)
 217
 218 if __name__ == '__main__':
 219     ExampleTest().main()