You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
190 lines
8.6 KiB
190 lines
8.6 KiB
# Functional tests
|
|
|
|
### Writing Functional Tests
|
|
|
|
#### Example test
|
|
|
|
The file [test/functional/example_test.py](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)
|
|
- The oldest supported Python version is specified in [doc/dependencies.md](/doc/dependencies.md).
|
|
Consider using [pyenv](https://github.com/pyenv/pyenv), which checks [.python-version](/.python-version),
|
|
to prevent accidentally introducing modern syntax from an unsupported Python version.
|
|
The CI linter job also checks this, but [possibly not in all cases](https://github.com/bitcoin/bitcoin/pull/14884#discussion_r239585126).
|
|
- See [the python lint script](/test/lint/lint-python.sh) that checks for violations that
|
|
could lead to bugs and issues in the test code.
|
|
- 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
|
|
- 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.
|
|
- Use `f'{x}'` for string formatting in preference to `'{}'.format(x)` or `'%s' % x`.
|
|
|
|
#### 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/README.md#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
|
|
|
|
- `P2P`s can be used to test specific P2P protocol behavior.
|
|
[p2p.py](test_framework/p2p.py) contains test framework p2p objects and
|
|
[messages.py](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.
|
|
|
|
`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](p2p_unrequested_blocks.py),
|
|
[p2p_compactblocks.py](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_framework).
|
|
|
|
#### [authproxy.py](test_framework/authproxy.py)
|
|
Taken from the [python-bitcoinrpc repository](https://github.com/jgarzik/python-bitcoinrpc).
|
|
|
|
#### [test_framework.py](test_framework/test_framework.py)
|
|
Base class for functional tests.
|
|
|
|
#### [util.py](test_framework/util.py)
|
|
Generally useful functions.
|
|
|
|
#### [p2p.py](test_framework/p2p.py)
|
|
Test objects for interacting with a bitcoind node over the p2p interface.
|
|
|
|
#### [script.py](test_framework/script.py)
|
|
Utilities for manipulating transaction scripts (originally from python-bitcoinlib)
|
|
|
|
#### [key.py](test_framework/key.py)
|
|
Test-only secp256k1 elliptic curve implementation
|
|
|
|
#### [blocktools.py](test_framework/blocktools.py)
|
|
Helper functions for creating blocks and transactions.
|
|
|
|
### Benchmarking 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.p2ps[0].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
|