diff --git a/doc/functional-tests.md b/doc/functional-tests.md index b9b7319fb..58baf98c7 100644 --- a/doc/functional-tests.md +++ b/doc/functional-tests.md @@ -1,392 +1,409 @@ # Functional tests The [/test/](/test/) directory contains integration tests that test bitcoind and its utilities in their entirety. It does not contain unit tests, which can be found in [/src/test](/src/test), [/src/wallet/test](/src/wallet/test), etc. There are currently two sets of tests in the [/test/](/test/) directory: - [functional](/test/functional) which test the functionality of bitcoind and bitcoin-qt by interacting with them through the RPC and P2P interfaces. - [util](/test/util) which tests the bitcoin utilities, currently only bitcoin-tx. The util tests are run as part of `make check` target. The functional tests are run by the Teamcity continuous build process whenever a diff is created or updated on Phabricator. Both sets of tests can also be run locally. # Running functional tests locally Build for your system first. Be sure to enable wallet, utils and daemon when you configure. Tests will not run otherwise. ### Functional tests #### Dependencies The ZMQ functional test requires a python ZMQ library. To install it: - On Unix, run `sudo apt-get install python3-zmq` - On mac OS, run `pip3 install pyzmq` #### Running the tests Individual tests can be run by directly calling the test script, eg: ``` test/functional/example_test.py ``` or can be run through the test_runner harness, eg: ``` test/functional/test_runner.py example_test ``` You can run any combination (incl. duplicates) of tests by calling: ``` test/functional/test_runner.py <testname1> <testname2> <testname3> ... ``` Run the regression test suite with: ``` test/functional/test_runner.py ``` Run all possible tests with ``` test/functional/test_runner.py --extended ``` By default, up to 4 tests will be run in parallel by test_runner. To specify how many jobs to run, append `--jobs=n` The individual tests and the test_runner harness have many command-line options. Run `test/functional/test_runner.py -h` to see them all. #### Troubleshooting and debugging test failures ##### Resource contention The P2P and RPC ports used by the bitcoind nodes-under-test are chosen to make conflicts with other processes unlikely. However, if there is another bitcoind process running on the system (perhaps from a previous test which hasn't successfully killed all its bitcoind nodes), then there may be a port conflict which will cause the test to fail. It is recommended that you run the tests on a system where no other bitcoind processes are running. On linux, the test framework will warn if there is another bitcoind process running when the tests are started. If there are zombie bitcoind processes after test failure, you can kill them by running the following commands. **Note that these commands will kill all bitcoind processes running on the system, so should not be used if any non-test bitcoind processes are being run.** ```bash killall bitcoind ``` or ```bash pkill -9 bitcoind ``` ##### Data directory cache A pre-mined blockchain with 200 blocks is generated the first time a functional test is run and is stored in test/cache. This speeds up test startup times since new blockchains don't need to be generated for each test. However, the cache may get into a bad state, in which case tests will fail. If this happens, remove the cache directory (and make sure bitcoind processes are stopped as above): ```bash rm -rf test/cache killall bitcoind ``` ##### Test logging The tests contain logging at different levels (debug, info, warning, etc). By default: - When run through the test_runner harness, *all* logs are written to `test_framework.log` and no logs are output to the console. - When run directly, *all* logs are written to `test_framework.log` and INFO level and above are output to the console. - When run by our CI, no logs are output to the console. However, if a test fails, the `test_framework.log` and bitcoind `debug.log`s will all be dumped to the console to help troubleshooting. These log files can be located under the test data directory (which is always printed in the first line of test output): - `<test data directory>/test_framework.log` - `<test data directory>/node<node number>/regtest/debug.log`. The node number identifies the relevant test node, starting from `node0`, which corresponds to its position in the nodes list of the specific test, e.g. `self.nodes[0]`. To change the level of logs output to the console, use the `-l` command line argument. `test_framework.log` and bitcoind `debug.log`s can be combined into a single aggregate log by running the `combine_logs.py` script. The output can be plain text, colorized text or html. For example: ``` test/functional/combine_logs.py -c <test data directory> | less -r ``` will pipe the colorized logs from the test into less. Use `--tracerpc` to trace out all the RPC calls and responses to the console. For some tests (eg any that use `submitblock` to submit a full block over RPC), this can result in a lot of screen output. By default, the test data directory will be deleted after a successful run. Use `--nocleanup` to leave the test data directory intact. The test data directory is never deleted after a failed test. ##### Attaching a debugger A python debugger can be attached to tests at any point. Just add the line: ```py import pdb; pdb.set_trace() ``` anywhere in the test. You will then be able to inspect variables, as well as call methods that interact with the bitcoind nodes-under-test. If further introspection of the bitcoind instances themselves becomes necessary, this can be accomplished by first setting a pdb breakpoint at an appropriate location, running the test to that point, then using `gdb` (or `lldb` on macOS) to attach to the process and debug. For instance, to attach to `self.node[1]` during a run you can get the pid of the node within `pdb`. ``` (pdb) self.node[1].process.pid ``` Alternatively, you can find the pid by inspecting the temp folder for the specific test you are running. The path to that folder is printed at the beginning of every test run: ```bash 2017-06-27 14:13:56.686000 TestFramework (INFO): Initializing test directory /tmp/user/1000/testo9vsdjo3 ``` Use the path to find the pid file in the temp folder: ```bash cat /tmp/user/1000/testo9vsdjo3/node1/regtest/bitcoind.pid ``` Then you can use the pid to start `gdb`: ```bash gdb /home/example/bitcoind <pid> ``` Note: gdb attach step may require `sudo`. To get rid of this, you can run: ```bash echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope ``` Often while debugging rpc calls from functional tests, the test might reach timeout before process can return a response. Use `--timeout-factor 0` to disable all rpc timeouts for that particular functional test. Ex: `test/functional/test_runner.py wallet_hd --timeout-factor 0`. ### Benchmarking and profiling with perf An easy way to profile node performance during functional tests is provided for Linux platforms using `perf`. Perf will sample the running node and will generate profile data in the node's datadir. The profile data can then be presented using `perf report` or a graphical tool like [hotspot](https://github.com/KDAB/hotspot). There are two ways of invoking perf: one is to use the `--perf` flag when running tests, which will profile each node during the entire test run: perf begins to profile when the node starts and ends when it shuts down. The other way is the use the `profile_with_perf` context manager, e.g. ```python with node.profile_with_perf("send-big-msgs"): # Perform activity on the node you're interested in profiling, e.g.: for _ in range(10000): node.p2p.send_message(some_large_message) ``` To see useful textual output, run ```sh perf report -i /path/to/datadir/send-big-msgs.perf.data.xxxx --stdio | c++filt | less ``` #### See also: - [Installing perf](https://askubuntu.com/q/50145) - [Perf examples](http://www.brendangregg.com/perf.html) - [Hotspot](https://github.com/KDAB/hotspot): a GUI for perf output analysis ##### Prevent using deprecated features Python will issue a `DeprecationWarning` when a deprecated feature is encountered in a script. By default, this warning message is ignored and not displayed to the user. This behavior can be changed by setting the environment variable `PYTHONWARNINGS` as follow: `PYTHONWARNINGS=default::DeprecationWarning` The warning message will now be printed to the `sys.stderr` output. ### Util tests Util tests can be run locally by running `test/util/bitcoin-util-test.py`. Use the `-v` option for verbose output. # Writing functional tests #### Example test The file [test/functional/example_test.py](/test/functional/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/functional/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](https://www.python.org/dev/peps/pep-0008/) - Use a python linter like flake8 before submitting PRs to catch common style nits (eg trailing whitespace, unused imports, etc) - Use [type hints](https://docs.python.org/3/library/typing.html) in your code to improve code readability and to detect possible bugs earlier. - 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 BitcoinTestFramework, 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. #### Naming guidelines - Name the test `<area>_test.py`, where area can be one of the following: - `feature` for tests for full features that aren't wallet/mining/mempool, eg `feature_rbf.py` - `interface` for tests for other interfaces (REST, ZMQ, etc), eg `interface_rest.py` - `mempool` for tests for mempool behaviour, eg `mempool_reorg.py` - `mining` for tests for mining features, eg `mining_prioritisetransaction.py` - `p2p` for tests that explicitly test the p2p interface, eg `p2p_disconnect_ban.py` - `rpc` for tests for individual RPC methods or features, eg `rpc_listtransactions.py` - `tool` for tests for tools, eg `tool_wallet.py` - `wallet` for tests for wallet features, eg `wallet_keypool.py` - Use an underscore to separate words - exception: for tests for specific RPCs or command line options which don't include underscores, name the test after the exact RPC or argument name, eg `rpc_decodescript.py`, not `rpc_decode_script.py` - Don't use the redundant word `test` in the name, eg `interface_zmq.py`, not `interface_zmq_test.py` #### General test-writing advice - Instead of inline comments or no test documentation at all, log the comments to the test log, e.g. `self.log.info('Create enough transactions to fill a block')`. Logs make the test code easier to read and the test logic easier [to debug](#test-logging). - 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). - 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 (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. - Many of the core test framework classes such as `CBlock` and `CTransaction` don't allow new attributes to be added to their objects at runtime like typical Python objects allow. This helps prevent unpredictable side effects from typographical errors or usage of the objects outside of their intended purpose. #### 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 -- [messages.py](/test/functional/test_framework/messages.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`s can be used to test specific P2P protocol behavior. +[p2p.py](/test/functional/test_framework/p2p.py) contains test framework +p2p objects and [messages.py](/test/functional/test_framework/messages.py) +contains all the definitions for objects passed 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 bitcoind(s) being tested in a callback-based event loop; the other implements the test logic. - `P2PConnection` is the class used to connect to a bitcoind. `P2PInterface` contains the higher level logic for processing P2P payloads and connecting to the Bitcoin Core node application logic. For custom behaviour, subclass the P2PInterface object and override the callback methods. -- Can be used to write tests where specific P2P protocol behavior is tested. -Examples tests are [p2p_unrequested_blocks.py](/test/functional/p2p_unrequested_blocks.py), +`P2PConnection`s can be used as such: + +```python +p2p_conn = node.add_p2p_connection(P2PInterface()) +p2p_conn.send_and_ping(msg) +``` + +They can also be referenced by indexing into a `TestNode`'s `p2ps` list, which +contains the list of test framework `p2p` objects connected to itself +(it does not include any `TestNode`s): + +```python +node.p2ps[0].sync_with_ping() +``` + +More examples can be found in [p2p_unrequested_blocks.py](/test/functional/p2p_unrequested_blocks.py), [p2p_compactblocks.py](/test/functional/p2p_compactblocks.py). #### Prototyping tests The [`TestShell`](test-shell.md) class exposes the BitcoinTestFramework functionality to interactive Python3 environments and can be used to prototype tests. This may be especially useful in a REPL environment with session logging utilities, such as [IPython](https://ipython.readthedocs.io/en/stable/interactive/reference.html#session-logging-and-restoring). The logs of such interactive sessions can later be adapted into permanent test cases. ### Test framework modules The following are useful modules for test developers. They are located in [test/functional/test_framework/](/test/functional/test_framework). #### [authproxy.py](/test/functional/test_framework/authproxy.py) Taken from the [python-bitcoinrpc repository](https://github.com/jgarzik/python-bitcoinrpc). #### [test_framework.py](/test/functional/test_framework/test_framework.py) Base class for functional tests. #### [util.py](/test/functional/test_framework/util.py) Generally useful functions. #### [p2p.py](/test/functional/test_framework/p2p.py) Test objects for interacting with a bitcoind node over the p2p interface. #### [script.py](/test/functional/test_framework/script.py) Utilities for manipulating transaction scripts (originally from python-bitcoinlib) #### [key.py](/test/functional/test_framework/key.py) Test-only secp256k1 elliptic curve implementation #### [blocktools.py](/test/functional/test_framework/blocktools.py) Helper functions for creating blocks and transactions.