How to add unit tests to C++ code
The indra C++ codebase is fraught with much peril. To reduce the amount of risk associated with refactoring legacy code, use unit tests. Here's how to use the new LL_ADD_PROJECT_UNIT_TESTS cmake macro and the existing tut test infrastructure to add a test to the build.
Overview
Tests go in a tests/ subdir of the project with the specific naming convention codefilename_test.cpp. The test code itself should use our basic tut template (which as of 2009-04 is somewhat in flux). Add a testing target to the bottom of the project using the cmake command LL_ADD_PROJECT_UNIT_TESTS(project sourcelist).
DO NOT add test code that:
- talks to a database.
- communicates across a network.
- touches the file system.
- requires doing special things to the environment (such as editing configuration files) to run it.
- takes longer than about ~.1s to run on a modern computer.
The unit test template
Copy this to a file indra/project/tests/codefile_test.cpp and follow the next section to make sure the build runs with it before you begin writing your test.
INSERT TUT TEMPLATE HERE
Code to make the unit test build
There is a macro that takes care of adding the proper testing targets to the build, you merely need to supply source files and a project name.
Basic example
This would go at the bottom of CMakeLists.txt for a project called "chewbacca". The exact quoting is important! CMake is very particular about list variables.
INCLUDE(LLAddBuildTest)
- NOTE: this is different from project_SOURCE_FILES because not all source has tests.
set(chewbacca_TESTED_SOURCE_FILES
chewbacca.cpp
person.cpp
)
LL_ADD_PROJECT_UNIT_TESTS(chewbacca "${chewbacca_TESTED_SOURCE_FILES}")
How to unit test your indra code
Insert Merov's doc here