Integration of property based testing into Bitcoin Cash Node

Summary:
This is an initial integration of the rapidcheck property based tests.
The original test has been slightly modified to adapt to our codebase.
The feature has been added to CMake and the documentation updated
accordingly.
Note that as opposed to autotools, which enables the test automatically
if `rapidcheck` is installed, it is disabled by default with cmake and
requires a flag to be set by the user.

Backport of core [[bitcoin/bitcoin#12775 | PR12775]], [[bitcoin/bitcoin#16622 | PR16622]] and [[bitcoin/bitcoin#16645 | PR16645]].

Test Plan:
Read the doc and install rapidcheck.

  ../configure
Ensure that rapidcheck is used by looking at the summary.
  make check

Ensure there is no regression:
  cmake -GNinja ..
  ninja check

  cmake -GNinja .. -DENABLE_PROPERTY_BASED_TESTS=ON
Check in the output that `rapidcheck` is enabled by searching for a
couple lines similar to:
```
  -- Found Rapidcheck: /usr/local/include
  -- Found Rapidcheck: /usr/local/lib/librapidcheck.a
```
  ninja check

Assuming you are running a 64-bit Linux machine:
  cd depends
  RAPIDCHECK=1 make build-linux64
Check the `rapidcheck` package is built.
  cd .. && mkdir buildLinux64 && cd buildLinux64
  cmake -GNinja .. \
    -DCMAKE_TOOLCHAIN_FILE=../cmake/platforms/Linux64.cmake \
    -DENABLE_PROPERTY_BASED_TESTS=ON
Check the `rapidcheck` lib found is the one from the `depends`.
  ninja check

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D5323

cmake/modules/FindRapidcheck.cmake

@@ -0,0 +1,64 @@
+# Copyright (c) 2020 The Bitcoin developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+# .rst:
+# FindRapidcheck
+# --------------
+#
+# Find the Rapidcheck library.
+#
+# This will define the following variables::
+#
+#   Rapidcheck_FOUND - True if the Rapidcheck library is found.
+#   Rapidcheck_INCLUDE_DIRS - List of the header include directories.
+#   Rapidcheck_LIBRARIES - List of the libraries.
+#
+# And the following imported targets::
+#
+#   Rapidcheck::Rapidcheck
+
+find_path(Rapidcheck_INCLUDE_DIR
+	NAMES rapidcheck.h
+	PATH_SUFFIXES rapidcheck
+)
+
+find_library(Rapidcheck_LIBRARY
+	NAMES rapidcheck
+	PATH_SUFFIXES rapidcheck
+)
+
+# TODO: extract a version number.
+# For now rapidcheck does not provide such a version number, and has no release.
+# See https://github.com/emil-e/rapidcheck/issues/235 for reference.
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Rapidcheck
+	DEFAULT_MSG
+	Rapidcheck_INCLUDE_DIR
+	Rapidcheck_LIBRARY
+)
+
+if(Rapidcheck_FOUND)
+	set(Rapidcheck_INCLUDE_DIRS "${Rapidcheck_INCLUDE_DIR}")
+	set(Rapidcheck_LIBRARIES "${Rapidcheck_LIBRARY}")
+
+	include(FindPackageMessage)
+	find_package_message(Rapidcheck
+		"Found Rapidcheck: ${Rapidcheck_LIBRARIES}"
+		"[${Rapidcheck_LIBRARIES}][${Rapidcheck_INCLUDE_DIRS}]"
+	)
+
+	if(NOT TARGET Rapidcheck::Rapidcheck)
+		add_library(Rapidcheck::Rapidcheck UNKNOWN IMPORTED)
+		set_target_properties(Rapidcheck::Rapidcheck PROPERTIES
+			INTERFACE_INCLUDE_DIRECTORIES "${Rapidcheck_INCLUDE_DIR}"
+			IMPORTED_LOCATION "${Rapidcheck_LIBRARY}"
+		)
+	endif()
+endif()
+
+mark_as_advanced(
+	Rapidcheck_INCLUDE_DIR
+	Rapidcheck_LIBRARY
+)

configure.ac

@@ -124,6 +124,12 @@ AC_ARG_ENABLE(gui-tests,
     [use_gui_tests=$enableval],
     [use_gui_tests=$use_tests])
 
+AC_ARG_WITH([rapidcheck],
+  [AS_HELP_STRING([--with-rapidcheck],
+  [enable RapidCheck property-based tests (default is yes if librapidcheck is found)])],
+  [use_rapidcheck=$withval],
+  [use_rapidcheck=auto])
+
 AC_ARG_ENABLE(bench,
     AS_HELP_STRING([--disable-bench],[do not compile benchmarks (default is to compile)]),
     [use_bench=$enableval],
@@ -1047,6 +1053,22 @@ AC_CHECK_DECLS([EVP_MD_CTX_new],,,[AC_INCLUDES_DEFAULT
 ])
 CXXFLAGS="${save_CXXFLAGS}"
 
+dnl RapidCheck property-based testing
+
+enable_property_tests=no
+if test "x$use_rapidcheck" = xauto; then
+    AC_CHECK_HEADERS([rapidcheck.h], [enable_property_tests=yes])
+elif test "x$use_rapidcheck" != xno; then
+    enable_property_tests=yes
+fi
+
+RAPIDCHECK_LIBS=
+if test "x$enable_property_tests" = xyes; then
+   RAPIDCHECK_LIBS=-lrapidcheck
+fi
+AC_SUBST(RAPIDCHECK_LIBS)
+AM_CONDITIONAL([ENABLE_PROPERTY_TESTS], [test x$enable_property_tests = xyes])
+
 dnl univalue check
 
 need_bundled_univalue=yes
@@ -1402,6 +1424,7 @@ fi
 echo "  with zmq      = $use_zmq"
 echo "  with test     = $use_tests"
 if test x$use_tests != xno; then
+    echo "    with prop   = $enable_property_tests"
     echo "    with fuzz   = $enable_fuzz"
 fi
 echo "  with bench    = $use_bench"

depends/Makefile

@@ -4,6 +4,7 @@ SOURCES_PATH ?= $(BASEDIR)/sources
 BASE_CACHE ?= $(BASEDIR)/built
 SDK_PATH ?= $(BASEDIR)/SDKs
 NO_QT ?=
+RAPIDCHECK ?=
 NO_WALLET ?=
 NO_UPNP ?=
 FALLBACK_DOWNLOAD_PATH ?= https://download.bitcoincashnode.org/depends-sources
@@ -94,13 +95,19 @@ qt_packages_$(NO_QT) = $(qt_packages) $(qt_$(host_os)_packages) $(qt_$(host_arch
 wallet_packages_$(NO_WALLET) = $(wallet_packages)
 upnp_packages_$(NO_UPNP) = $(upnp_packages)
 
+rapidcheck_packages_$(RAPIDCHECK) = $(rapidcheck_packages)
+
 packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(qt_packages_) $(wallet_packages_) $(upnp_packages_)
 native_packages += $($(host_arch)_$(host_os)_native_packages) $($(host_os)_native_packages)
 
 ifneq ($(qt_packages_),)
 native_packages += $(qt_native_packages)
 endif
 
+ifeq ($(rapidcheck_packages_),)
+packages += $(rapidcheck_packages)
+endif
+
 all_packages = $(packages) $(native_packages)
 
 meta_depends = Makefile funcs.mk builders/default.mk hosts/default.mk hosts/$(host_os).mk builders/$(build_os).mk

depends/README.md

@@ -39,6 +39,7 @@ The following can be set when running make: make FOO=bar
     NO_WALLET: Don't download/build/cache libs needed to enable the wallet
     NO_UPNP: Don't download/build/cache packages needed for enabling upnp
     DEBUG: disable some optimizations and enable more runtime checking
+    RAPIDCHECK: build rapidcheck (experimental)
     HOST_ID_SALT: Optional salt to use when generating host package ids
     BUILD_ID_SALT: Optional salt to use when generating build package ids
     JOBS: Number of jobs to use for each package build

depends/packages/packages.mk

@@ -5,6 +5,8 @@ qt_packages = qrencode protobuf zlib
 
 qt_linux_packages:=qt expat dbus libxcb xcb_proto libXau xproto freetype fontconfig libX11 xextproto libXext xtrans
 
+rapidcheck_packages = rapidcheck
+
 qt_darwin_packages=qt
 qt_mingw32_packages=qt
 

depends/packages/rapidcheck.mk

@@ -0,0 +1,18 @@
+package=rapidcheck
+$(package)_version=10fc0cb
+$(package)_download_path=https://github.com/MarcoFalke/rapidcheck/archive
+$(package)_file_name=$(package)-$($(package)_version).tar.gz
+$(package)_sha256_hash=9640926223c00af45bce4c7df8b756b5458a89b2ba74cfe3e404467f13ce26df
+
+define $(package)_config_cmds
+  cmake -DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=true .
+endef
+
+define $(package)_build_cmds
+  $(MAKE) -j$(JOBS) && \
+  mkdir -p $($(package)_staging_dir)$(host_prefix)/include && \
+  cp -a include/* $($(package)_staging_dir)$(host_prefix)/include/ && \
+  cp -a extras/boost_test/include/rapidcheck/* $($(package)_staging_dir)$(host_prefix)/include/rapidcheck/ && \
+  mkdir -p $($(package)_staging_dir)$(host_prefix)/lib && \
+  cp -a librapidcheck.a $($(package)_staging_dir)$(host_prefix)/lib/
+endef

doc/rapidcheck.md

@@ -0,0 +1,69 @@
+# RapidCheck property-based testing for Bitcoin Cash Node
+
+## Concept
+
+Property-based testing is experimentally being added to Bitcoin Cash Node with
+[RapidCheck](https://github.com/emil-e/rapidcheck), a C++ framework for
+property-based testing inspired by the Haskell library
+[QuickCheck](https://hackage.haskell.org/package/QuickCheck).
+
+RapidCheck performs random testing of program properties. A specification of the
+program is given in the form of properties which functions should satisfy, and
+RapidCheck tests that the properties hold in a large number of randomly
+generated cases.
+
+If an exception is found, RapidCheck tries to find the smallest case, for some
+definition of smallest, for which the property is still false and displays it as
+a counter-example. For example, if the input is an integer, RapidCheck tries to
+find the smallest integer for which the property is false.
+
+## Setup
+
+The following instructions have been tested with Linux Debian and macOS.
+
+1. Clone the RapidCheck source code and cd into the repository.
+
+    ```shell
+    git clone https://github.com/emil-e/rapidcheck.git
+    cd rapidcheck
+    ```
+
+2. Build RapidCheck.
+
+    ```shell
+    mkdir build
+    cd build
+    cmake -GNinja .. -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DRC_ENABLE_BOOST_TEST=ON
+    ninja
+    sudo ninja install/strip
+    ```
+
+3. Configure Bitcoin Cash Node with RapidCheck.
+
+    `cd` to the directory of your local Bitcoin Cash Node repository, create a build
+    directory and run cmake:
+
+    ```shell
+    mkdir build
+    cd build
+    cmake -GNinja .. -DENABLE_PROPERTY_BASED_TESTS=ON
+    ```
+
+    In the output you should see something similar to:
+
+    ```shell
+    [...]
+    -- Found Rapidcheck: /usr/local/include
+    -- Found Rapidcheck: /usr/local/lib/librapidcheck.a
+    [...]
+    ```
+
+4. Build Bitcoin Cash Node with RapidCheck.
+
+    Now you can run `ninja check` to build and run the unit tests, including the
+    property-based tests. You can also build and run a single test by using
+    `ninja check-bitcoin-<test_name>`.
+
+    Example: `ninja check-bitcoin-key_properties`
+
+That's it! You are now running property-based tests in Bitcoin Cash Node.

src/Makefile.test.include

@@ -35,6 +35,7 @@ TEST_SRCDIR = test
 TEST_BINARY=test/test_bitcoin$(EXEEXT)
 
 JSON_TEST_FILES = \
+  test/data/script_tests.json \
   test/data/base58_encode_decode.json \
   test/data/blockfilters.json \
   test/data/key_io_valid.json \
@@ -168,6 +169,15 @@ BITCOIN_TESTS =\
   test/work_comparator_tests.cpp \
   rpc/test/server_tests.cpp
 
+if ENABLE_PROPERTY_TESTS
+BITCOIN_TESTS += \
+  test/key_properties.cpp
+
+BITCOIN_TEST_SUITE += \
+  test/gen/crypto_gen.cpp \
+  test/gen/crypto_gen.h
+endif
+
 if ENABLE_WALLET
 BITCOIN_TESTS += \
   wallet/test/db_tests.cpp \
@@ -196,7 +206,7 @@ test_test_bitcoin_LDADD += $(LIBBITCOIN_SERVER) $(LIBBITCOIN_CLI) $(LIBBITCOIN_C
   $(LIBLEVELDB) $(LIBLEVELDB_SSE42) $(LIBMEMENV) $(BOOST_LIBS) $(BOOST_UNIT_TEST_FRAMEWORK_LIB) $(LIBSECP256K1) $(EVENT_LIBS) $(EVENT_PTHREADS_LIBS)
 test_test_bitcoin_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 
-test_test_bitcoin_LDADD += $(LIBBITCOIN_CONSENSUS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS)
+test_test_bitcoin_LDADD += $(LIBBITCOIN_CONSENSUS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS) $(RAPIDCHECK_LIBS)
 test_test_bitcoin_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) -static
 
 if ENABLE_ZMQ

src/test/CMakeLists.txt

@@ -2,6 +2,8 @@
 
 project(bitcoin-test)
 
+option(ENABLE_PROPERTY_BASED_TESTS "Enable property based tests" OFF)
+
 # Process json files.
 file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/data")
 
@@ -59,6 +61,17 @@ if(BUILD_BITCOIN_WALLET)
 	)
 endif()
 
+if(ENABLE_PROPERTY_BASED_TESTS)
+	find_package(Rapidcheck REQUIRED)
+
+	set(BITCOIN_PROPERTY_BASED_TEST_FIXTURE
+		gen/crypto_gen.cpp
+	)
+	set(BITCOIN_PROPERTY_BASED_TESTS
+		key_properties.cpp
+	)
+endif()
+
 add_boost_unit_tests_to_suite(bitcoin test_bitcoin
 	jsonutil.cpp
 	main.cpp
@@ -72,6 +85,9 @@ add_boost_unit_tests_to_suite(bitcoin test_bitcoin
 	# Wallet test fixture
 	${BITCOIN_WALLET_TEST_FIXTURE}
 
+	# Properties based test fixture
+	${BITCOIN_PROPERTY_BASED_TEST_FIXTURE}
+
 	TESTS
 		activation_tests.cpp
 		addrman_tests.cpp
@@ -178,8 +194,15 @@ add_boost_unit_tests_to_suite(bitcoin test_bitcoin
 
 		# Wallet tests
 		${BITCOIN_WALLET_TESTS}
+
+		# Properties based tests
+		${BITCOIN_PROPERTY_BASED_TESTS}
 )
 
+if(ENABLE_PROPERTY_BASED_TESTS)
+	target_link_libraries(test_bitcoin Rapidcheck::Rapidcheck)
+endif()
+
 target_link_libraries(test_bitcoin rpcclient server)
 if(TARGET bitcoinconsensus-shared)
 	target_link_libraries(test_bitcoin bitcoinconsensus-shared)

src/test/gen/crypto_gen.cpp

@@ -0,0 +1,19 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#include <test/gen/crypto_gen.h>
+
+#include <key.h>
+
+#include <rapidcheck/Gen.h>
+#include <rapidcheck/gen/Arbitrary.h>
+#include <rapidcheck/gen/Container.h>
+#include <rapidcheck/gen/Predicate.h>
+
+/** Generates 1 to 20 keys for OP_CHECKMULTISIG */
+rc::Gen<std::vector<CKey>> MultisigKeys() {
+    return rc::gen::suchThat(rc::gen::arbitrary<std::vector<CKey>>(),
+                             [](const std::vector<CKey> &keys) {
+                                 return keys.size() >= 1 && keys.size() <= 15;
+                             });
+};