added Catch2 as unit testing framework

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "code/ext/spdlog"]
 	path = code/ext/spdlog
 	url = git://github.com/gabime/spdlog.git
+[submodule "code/ext/Catch2"]
+	path = code/ext/Catch2
+	url = git://github.com/catchorg/Catch2.git

README.md

@@ -6,8 +6,10 @@ TBD
 ### Examples
 TBD
 
+---
+
 ## Build
-### System dependencies
+### Required dependencies
  - Compiler with C++17 support (GCC >= v6, clang >= v3.8)
  - cmake >= v3.5
  - LAPACK
@@ -25,7 +27,7 @@ git submodule init
 git submodule update
 ```
 
-### Compile
+### Compile the code
 **Make** build system (available on most systems)
  
 ```bash 
@@ -45,7 +47,9 @@ ninja
 
 
 The resulting executable will automatically be placed in the `code/bin` folder.
- 
+
+---
+
 ## Run
 ### Local
 Execute the compiled binary and hand over a valid *TOML*-styled config file.
@@ -66,11 +70,29 @@ with `N` equal to the number of shared memory threads and `J` equal to the numbe
 ### BwUniCluster
 TBD
 
+---
+
+## Tests
+In order to also compile the unit tests, add `-DBUILD_TESTING=True` to the cmake command, e.g.:
+
+```bash
+cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_TESTING=True ../../
+```
+
+The resulting `unit_tests` executable will also be placed in `/bin`.
+
+## Continuous Integration (CI)
+TBD
+
+---
+
 ## Code structure
 ![Can't load image](doc/uml.png "UML diagram")
 <br/><br/>
 The diagram can be modified by opening `doc/uml.zargo` with `ArgoUML`.
 
+---
+
 ## Coding style
 Please stick to the following coding style for easier code readability:
 

code/.gitlab-ci.yml

+image: ubuntu:18.04
+
+stages:
+  - build
+  - test
+
+build:
+  stage: build
+  script:
+    - apt-get update
+    - apt-get install -y g++ cmake libopenmpi-dev libblas-dev liblapack-dev git ninja-build
+    - git submodule update --init --recursive
+    - cd code/build/debug
+    - cmake -G Ninja -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=True -DCMAKE_EXPORT_COMPILE_COMMANDS=True ../../
+    - ninja
+
+test:
+  stage: test
+  script:
+    - bin/unit_tests

code/CMakeLists.txt

 cmake_minimum_required( VERSION 3.5 )
-project( RTSN )
+project( RTSN LANGUAGES CXX VERSION 0.0.1 )
 set( CMAKE_CXX_STANDARD 17 )
 
 set( CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -march=native" )
 set( CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -O3 -march=native -pg -no-pie" )
 set( CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0 -Wall -Werror" )
 
-set( CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin/" )
+set( CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin" )
 
-file(GLOB_RECURSE SRCS RELATIVE ${CMAKE_SOURCE_DIR} "src/*.cpp")
+file( GLOB_RECURSE SRCS RELATIVE ${CMAKE_SOURCE_DIR} "src/*.cpp" )
+include_directories( ${CMAKE_SOURCE_DIR}/include )
 add_executable( ${CMAKE_PROJECT_NAME} ${SRCS} )
 
 find_package( OpenMP REQUIRED )
@@ -23,12 +24,26 @@ include_directories( ${MPI_INCLUDE_PATH} )
 find_package( LAPACK REQUIRED )
 include_directories( ${LAPACK_INCLUDE_DIR} )
 
+include_directories( ${CMAKE_SOURCE_DIR}/../ext/cpptoml/include )
+include_directories( ${CMAKE_SOURCE_DIR}/../ext/spdlog/include )
+
 execute_process(
     COMMAND git rev-parse HEAD
     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
     OUTPUT_VARIABLE GIT_HASH
     OUTPUT_STRIP_TRAILING_WHITESPACE
 )
-add_definitions('-DGIT_HASH="${GIT_HASH}"')
+add_definitions( '-DGIT_HASH="${GIT_HASH}"' )
+
+set( CORE_LIBRARIES ${LAPACK_LIBRARIES} ${MPI_LIBRARIES} -lstdc++fs )
 
-target_link_libraries( ${CMAKE_PROJECT_NAME} ${LAPACK_LIBRARIES} ${VTK_LIBRARIES} ${MPI_LIBRARIES} -lstdc++fs)
+target_link_libraries( ${CMAKE_PROJECT_NAME} ${CORE_LIBRARIES} )
+
+if( BUILD_TESTING )
+    add_subdirectory( ${CMAKE_SOURCE_DIR}/ext/Catch2 )
+    include_directories( ${CMAKE_SOURCE_DIR}/ext/Catch2/single_include/catch2 )
+    file( GLOB_RECURSE TEST_SRCS RELATIVE ${CMAKE_SOURCE_DIR} "tests/*.cpp" )
+    list( REMOVE_ITEM SRCS "src/main.cpp" )
+    add_executable( unit_tests ${SRCS} ${TEST_SRCS} )
+    target_link_libraries( unit_tests ${CORE_LIBRARIES} )
+endif()

Catch2 @ 255aa5f2

+Subproject commit 255aa5f2afe1a622c97422f65ace6ca915be0d8d

code/include/factorial_example.h

+unsigned int Factorial( unsigned int number );

code/src/factorial_example.cpp

+#include "factorial_example.h"
+
+unsigned int Factorial( unsigned int number ) { return number > 1 ? Factorial( number - 1 ) * number : 1; }

code/tests/factorial_example_test.cpp

+#include "catch.hpp"
+
+#include "factorial_example.h"
+
+TEST_CASE( "Factorials are computed", "[factorial]" ) {
+    REQUIRE( Factorial( 0 ) == 1 );
+    REQUIRE( Factorial( 1 ) == 1 );
+    REQUIRE( Factorial( 2 ) == 2 );
+    REQUIRE( Factorial( 3 ) == 6 );
+    REQUIRE( Factorial( 10 ) == 3628800 );
+}

code/tests/tests_main.cpp

+#define CATCH_CONFIG_MAIN
+#include "catch.hpp"