Writing Functional Tests
The example_test.py is a heavily commented example of a test case that uses both the RPC and P2P interfaces. If you are writing your first test, copy that file and modify to fit your needs.
test_runner.py with the
--coverage argument tracks which RPCs are
called by the tests and prints a report of uncovered RPCs in the summary. This
can be used (along with the
--extended argument) to find out which RPCs we
don't have test cases for.
- Where possible, try to adhere to PEP-8 guidelines
- Use a python linter like flake8 before submitting PRs to catch common style nits (eg trailing whitespace, unused imports, etc)
- Avoid wildcard imports where possible
- Use a module-level docstring to describe what the test is testing, and how it is testing it.
- When subclassing the BitcoinTestFramwork, place overrides for the
setup_xxxx()methods at the top of the subclass, then locally-defined helper methods, then the
General test-writing advice
self.num_nodesto the minimum number of nodes necessary for the test. Having additional unrequired nodes adds to the execution time of the test as well as memory/CPU/disk requirements (which is important when running tests in parallel or on Travis).
- Avoid stop-starting the nodes multiple times during the test if possible. A stop-start takes several seconds, so doing it several times blows up the runtime of the test.
- Set the
set_test_params()to control whether or not to use the cached data directories. The cached data directories contain a 200-block pre-mined blockchain and wallets for four nodes. Each node has 25 mature blocks (25x50=1250 BTC) in its wallet.
- When calling RPCs with lots of arguments, consider using named keyword arguments instead of positional arguments to make the intent of the call clear to readers.
RPC and P2P definitions
Test writers may find it helpful to refer to the definitions for the RPC and P2P messages. These can be found in the following source files:
/src/wallet/rpc*for wallet RPCs
/src/net_processing.cppfor parsing P2P messages
Using the P2P interface
mininode.pycontains all the definitions for objects that pass over the network (
CTransaction, etc, along with the network-level wrappers for them,
P2P tests have two threads. One thread handles all network communication with the bitcoind(s) being tested (using python's asyncore package); the other implements the test logic.
NodeConnis the class used to connect to a bitcoind. If you implement a callback class that derives from
NodeConnCBand pass that to the
NodeConnobject, your code will receive the appropriate callbacks when events of interest arrive.
NodeConnobjects are created to start the networking thread. (Continue with the test logic in your existing thread.)
Can be used to write tests where specific P2P protocol behavior is tested. Examples tests are
Comptool is a Testing framework for writing tests that compare the block/tx acceptance behavior of a bitcoind against 1 or more other bitcoind instances. It should not be used to write static tests with known outcomes, since that type of test is easier to write and maintain using the standard BitcoinTestFramework.
num_nodesvariable (defined in
ComparisonTestFramework) to start up 1 or more nodes. If using 1 node, then
--testbinarycan be used as a command line option to change the bitcoind binary used by the test. If using 2 or more nodes, then
--refbinarycan be optionally used to change the bitcoind that will be used on nodes 2 and up.
Implement a (generator) function called
- A list of
[object, outcome, hash]entries
CTransaction's are tested for acceptance.
CBlockHeaders can be used so that the test runner can deliver complete headers-chains when requested from the bitcoind, to allow writing tests where blocks can be delivered out of order but still processed by headers-first bitcoind's.
False, the tip is compared with the expected tip -- either the block passed in, or the hash specified as the optional 3rd entry. If
Noneis specified, then the test will compare all the bitcoind's being tested to see if they all agree on what the best tip is.
hashis the block hash of the tip to compare against. Optional to specify; if left out then the hash of the block passed in will be used as the expected tip. This allows for specifying an expected tip while testing the handling of either invalid blocks or blocks delivered out of order, which complete a longer chain.
False, then all blocks are inv'ed together, and the test runner waits until the node receives the last one, and tests only the last block for tip acceptance using the outcome and specified tip. If
True, then each block is tested in sequence and synced (this is slower when processing many blocks).
True/False. Analogous to
sync_every_block, except if the outcome on the last tx is "None", then the contents of the entire mempool are compared across all bitcoind connections. If
False, then only the last tx's acceptance is tested against the given outcome.
- A list of
For examples of tests written in this framework, see
Taken from the python-bitcoinrpc repository.
Base class for functional tests.
Generally useful functions.
Basic code to support P2P connectivity to a bitcoind.
Framework for comparison-tool style, P2P tests.
Utilities for manipulating transaction scripts (originally from python-bitcoinlib)
Implements disk-backed block and tx storage.
Wrapper around OpenSSL EC_Key (originally from python-bitcoinlib)
Helpers for script.py
Helper functions for creating blocks and transactions.