Add an example of unit-tests

[NickVolynkin]

A normal development workflow includes writing and running unit-tests. We should have an example of tests in this template.

For reference, see https://github.com/color-typea/lido-zkllvm-accounting-curcuit/tree/minimal_setup_with_tests_and_crypto3 (commit color-typea/lido-zkllvm-accounting-circuit@41327cb)

Updated version of this branch is in https://github.com/NilFoundation/zkllvm-template/tree/minimal_setup_with_tests_and_crypto3 and #28

Smaller example is shown in #29

[color-typea]

Some additional insight:

Command to build a circuit in main (as seen by adding VERBOSE=1 to build command: VERBOSE=1 cmake --build ./build --target template):

cd /opt/circuit/build/src && clang -target assigner -Xclang -no-opaque-pointers -Xclang -fpreserve-vec3-type -std=c++20 -D__ZKLLVM__ -I/opt/circuit/libs/crypto3/libs/algebra/include -I/opt/circuit/build/include -I/opt/boost_1_76_0/include -I -I/opt/circuit/libs/crypto3/libs/block/include -I/opt/boost_1_76_0/include -I/opt/circuit/libs/crypto3/libs/codec/include -I/opt/circuit/libs/crypto3/libs/containers/include -I/opt/circuit/libs/crypto3/libs/hash/include -I/opt/circuit/libs/crypto3/libs/kdf/include -I/opt/circuit/libs/crypto3/libs/mac/include -I/opt/circuit/libs/crypto3/libs/marshalling/core/include -I/opt/circuit/libs/crypto3/libs/marshalling/algebra/include -I/opt/circuit/libs/crypto3/libs/marshalling/multiprecision/include -I/opt/circuit/libs/crypto3/libs/marshalling/zk/include -I/opt/circuit/libs/crypto3/libs/math/include -I/opt/circuit/libs/crypto3/libs/modes/include -I/opt/circuit/libs/crypto3/libs/multiprecision/include -I/opt/circuit/libs/crypto3/libs/passhash/include -I/opt/circuit/libs/crypto3/libs/pbkdf/include -I/opt/circuit/libs/crypto3/libs/pkmodes/include -I/opt/circuit/libs/crypto3/libs/pkpad/include -I/opt/circuit/libs/crypto3/libs/pubkey/include -I/opt/circuit/libs/crypto3/libs/random/include -I/opt/circuit/libs/crypto3/libs/stream/include -I/opt/circuit/libs/crypto3/libs/vdf/include -I/opt/circuit/libs/crypto3/libs/zk/include -I/opt/circuit/src -emit-llvm -O1 -S -o lido_accounting_circuit.ll /opt/circuit/src/circuit.cpp

Command to build tests:

cd /opt/circuit/build/test && /usr/bin/c++ -DBOOST_ALL_NO_LIB -DBOOST_CONTAINER_DYN_LINK -DBOOST_RANDOM_DYN_LINK -DBOOST_SYSTEM_DYN_LINK -DBOOST_TEST_DYN_LINK=1 -DBOOST_TEST_NO_AUTO_LINK=1 -DBOOST_UNIT_TEST_FRAMEWORK_DYN_LINK -DCRYPTO3_CODEC_BASE58 -DCRYPTO3_HAS_AVX2 -DCRYPTO3_HAS_CHACHA_AVX2 -DCRYPTO3_HAS_RIJNDAEL_NI -DCRYPTO3_VDF_BOOST -I/opt/circuit/test -I/opt/circuit/src -I/opt/circuit/libs/crypto3/libs/algebra/include -I/opt/circuit/build/include -I/opt/circuit/libs/crypto3/libs/hash/include -I/opt/circuit/libs/crypto3/libs/multiprecision/include -I/opt/circuit/libs/crypto3/libs/marshalling/algebra/include -I/opt/circuit/libs/crypto3/libs/marshalling/multiprecision/include -I/opt/circuit/libs/crypto3/libs/marshalling/core/include -I/opt/circuit/libs/crypto3/libs/block/include -I/opt/circuit/libs/crypto3/libs/codec/include -I/opt/circuit/libs/crypto3/libs/containers/include -I/opt/circuit/libs/crypto3/libs/kdf/include -I/opt/circuit/libs/crypto3/libs/mac/include -I/opt/circuit/libs/crypto3/libs/modes/include -I/opt/circuit/libs/crypto3/libs/marshalling/zk/include -I/opt/circuit/libs/crypto3/libs/zk/include -I/opt/circuit/libs/crypto3/libs/math/include -I/opt/circuit/libs/crypto3/libs/pubkey/include -I/opt/circuit/libs/crypto3/libs/pkpad/include -I/opt/circuit/libs/crypto3/libs/passhash/include -I/opt/circuit/libs/crypto3/libs/pbkdf/include -I/opt/circuit/libs/crypto3/libs/pkmodes/include -I/opt/circuit/libs/crypto3/libs/random/include -I/opt/circuit/libs/crypto3/libs/stream/include -I/opt/circuit/libs/crypto3/libs/vdf/include -isystem /opt/boost_1_76_0/include -O3 -DNDEBUG -fconstexpr-ops-limit=4294967295 -mavx2 -maes -mpclmul -mssse3 -O3 -fno-rtti -std=gnu++20 -MD -MT test/CMakeFiles/lib_test.dir/lib.cpp.o -MF CMakeFiles/lib_test.dir/lib.cpp.o.d -o CMakeFiles/lib_test.dir/lib.cpp.o -c /opt/circuit/test/lib.cpp

Note:

1. Different compilers - "main" build uses clang, "test" build uses c++
2. Main sets __ZKLLVM__ definition, while tests do not - and it is used throughout crypto3 (e.g. this place in crypto3::hash might be directly relevant)