dash/test/functional/README.md

Functional tests

Writing Functional Tests

Example test

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.

Coverage

Running 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.

Style guidelines

• 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 set_test_params(), add_options() and setup_xxxx() methods at the top of the subclass, then locally-defined helper methods, then the run_test() method.

General test-writing advice

• Set self.num_nodes to 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 self.setup_clean_chain variable in 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 (25x500=12500 DASH) 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/rpc/* for RPCs
• /src/wallet/rpc* for wallet RPCs
• ProcessMessage() in /src/net_processing.cpp for parsing P2P messages

Using the P2P interface

• mininode.py contains all the definitions for objects that pass over the network (CBlock, CTransaction, etc, along with the network-level wrappers for them, msg_block, msg_tx, etc).

• P2P tests have two threads. One thread handles all network communication with the dashd(s) being tested (using python's asyncore package); the other implements the test logic.

• NodeConn is the class used to connect to a dashd. If you implement a callback class that derives from NodeConnCB and pass that to the NodeConn object, your code will receive the appropriate callbacks when events of interest arrive.

• Call network_thread_start() after all NodeConn objects 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 p2p-accept-block.py, p2p-compactblocks.py.

test-framework modules

test_framework/authproxy.py

Taken from the python-bitcoinrpc repository.

test_framework/test_framework.py

Base class for functional tests.

test_framework/util.py

Generally useful functions.

test_framework/mininode.py

Basic code to support P2P connectivity to a dashd.

test_framework/script.py

Utilities for manipulating transaction scripts (originally from python-bitcoinlib)

test_framework/key.py

Wrapper around OpenSSL EC_Key (originally from python-bitcoinlib)

test_framework/bignum.py

Helpers for script.py

test_framework/blocktools.py

Helper functions for creating blocks and transactions.