Previously, the validation_chainstatemanager_tests test suite
instantiated its own duplicate ChainstateManager on which tests were
performed.
This wasn't a problem for the specific actions performed in
that suite. However, the existence of this duplicate ChainstateManager
and the fact that many of our validation static functions reach for
g_chainman, ::Chain(state|)Active means we may end up acting on two
different CChainStates should we write more extensive tests in the
future.
This change adds a new ChainTestingSetup which performs all
initialization previously done by TestingSetup except:
1. RPC command registration
2. ChainState initialization
3. Genesis Activation
4. {Ban,Conn,Peer}Man initialization
Means that we will no longer need to initialize a duplicate
ChainstateManger in order to test the initialization codepaths of
CChainState and ChainstateManager.
Lastly, this change has the additional benefit of allowing for
review-only assertions meant to show correctness to work in future work
de-globalizing g_chainman.
In the test chainstatemanager_rebalance_caches, an additional
LoadGenesisBlock call is added as MaybeReblanaceCaches eventually calls
FlushBlockFile, which tries to access vinfoBlockFile[nLastBlockFile],
which is out of bounds when LoadGenesisBlock hasn't been called yet.
-----
Note for the future:
The class con/destructor inheritance structure we have for these
TestingSetup classes is probably not the most suitable abstraction. In
particular, for both TestingSetup and ChainTestingSetup, we need to stop
the scheduler first before anything else. Otherwise classes depending on
the scheduler may be referenced by the scheduler after said classes are
freed. This means that there's no clear parallel between our teardown
code and C++'s destructuring order for class hierarchies.
Future work should strive to coalesce (as much as possible) test and
non-test init codepaths and perhaps structure it in a more fail-proof
way.
Unit tests
The sources in this directory are unit test cases. Boost includes a unit testing framework, and since Bitcoin Core already uses Boost, it makes sense to simply use this framework rather than require developers to configure some other framework (we want as few impediments to creating unit tests as possible).
The build system is set up to compile an executable called test_bitcoin
that runs all of the unit tests. The main source file for the test library is found in
util/setup_common.cpp.
Compiling/running unit tests
Unit tests will be automatically compiled if dependencies were met in ./configure
and tests weren't explicitly disabled.
After configuring, they can be run with make check.
To run the unit tests manually, launch src/test/test_bitcoin. To recompile
after a test file was modified, run make and then run the test again. If you
modify a non-test file, use make -C src/test to recompile only what's needed
to run the unit tests.
To add more unit tests, add BOOST_AUTO_TEST_CASE functions to the existing
.cpp files in the test/ directory or add new .cpp files that
implement new BOOST_AUTO_TEST_SUITE sections.
To run the GUI unit tests manually, launch src/qt/test/test_bitcoin-qt
To add more GUI unit tests, add them to the src/qt/test/ directory and
the src/qt/test/test_main.cpp file.
Running individual tests
test_bitcoin has some built-in command-line arguments; for
example, to run just the getarg_tests verbosely:
test_bitcoin --log_level=all --run_test=getarg_tests -- DEBUG_LOG_OUT
log_level controls the verbosity of the test framework, which logs when a
test case is entered, for example. The DEBUG_LOG_OUT after the two dashes
redirects the debug log, which would normally go to a file in the test datadir
(BasicTestingSetup::m_path_root), to the standard terminal output.
... or to run just the doubledash test:
test_bitcoin --run_test=getarg_tests/doubledash
Run test_bitcoin --help for the full list.
Adding test cases
To add a new unit test file to our test suite you need
to add the file to src/Makefile.test.include. The pattern is to create
one test file for each class or source file for which you want to create
unit tests. The file naming convention is <source_filename>_tests.cpp
and such files should wrap their tests in a test suite
called <source_filename>_tests. For an example of this pattern,
see uint256_tests.cpp.
Logging and debugging in unit tests
make check will write to a log file foo_tests.cpp.log and display this file
on failure. For running individual tests verbosely, refer to the section
above.
To write to logs from unit tests you need to use specific message methods
provided by Boost. The simplest is BOOST_TEST_MESSAGE.
For debugging you can launch the test_bitcoin executable with gdbor lldb and
start debugging, just like you would with any other program:
gdb src/test/test_bitcoin