CTest Unity Example

This is a simple example of a C application which can build and run unit tests with CTest.

It uses Unity as a test framework.

Conventions

This application has all of its source files in a folder called src and all test files in test. These can be changed in CMakeLists.txt.

By convention, test a file named src/module.c by adding a test file called test/test_module.c. This file will be built and linked against the source file to execute the tests. The test_ is the prefix for a test file name, but this prefix can be changed in CMakeLists.txt.

Adding New Modules and Tests

Add a new module and test by creating three different files:

• src/<module_name>.c
• src/<module_name>.h
• test/test_<module_name.c>

The test file created should include

Running CMake

The modern way to build with CMake is to create a build dir with:

cmake -S . -B build

This tells CMake the source and build directories and then generates the build system.

Then instead of running the built makefiles (or Ninja files) directly, use CMake to run the build tool with the --build option:

cmake --build build

Running Tests

After 1) the build system has been generated and 2) the build is run, the tests can be run with CTest.

ctest --test-dir build

The build folder must be supplied to CTest with the --test-dir argument so that CTest knows where to find the tests.

Implementation Details

Subdirectories

You could put a CMakeLists folder in the test folder and then include it with:

add_subdirectory(test)

When it is time to run the tests though, you need to run them by speficifing the build subdirectory:

ctest --test-dir build/test

To Do

You can use gcc to determine module dependencies like this:

gcc -MM test\test_module_1.c -Isrc -Itest
test_module_1.o: test\test_module_1.c src/module.h

This could be useful for automatically detecting the files to include in the test executable.