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Writing Basic Tests with C++ with GTest

Starting point: we’ll assume you have a basic ament_cmake package set up already and you want to add some tests to it.

In this tutorial, we’ll be using gtest.

Package Setup

Source Code

We’ll start off with our code in a file called test/tutorial_test.cpp

#include <gtest/gtest.h>

TEST(package_name, a_first_test)
{
  ASSERT_EQ(4, 2 + 2);
}

int main(int argc, char ** argv)
{
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}

package.xml

Add the following line to package.xml

<test_depend>ament_cmake_gtest</test_depend>

CMakeLists.txt

if(BUILD_TESTING)
  find_package(ament_cmake_gtest REQUIRED)
  ament_add_gtest(${PROJECT_NAME}_tutorial_test test/tutorial_test.cpp)
  target_include_directories(${PROJECT_NAME}_tutorial_test PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    $<INSTALL_INTERFACE:include>
  )
  target_link_libraries(${PROJECT_NAME}_tutorial_test name_of_local_library)
endif()

The testing code is wrapped in the if/endif block to avoid building tests where possible. ament_add_gtest functions much like add_executable so you’ll need to call target_include_directories, ament_target_dependencies and target_link_libraries as you normally would.

Running Tests

See the tutorial on how to run tests from the command line for more information on running the tests and inspecting the test results.