Meliorate

Meliorate is a code generator and test runner for C++.

It aims to:

• Simplify the writing and execution of tests.
• Minimise the amount of strange code (macro magic) often associated with C++ unit test libraries.

Meliorate uses Clang to identify test functions (functions beginning with the word test) and generates all code necessary to run test functions automatically.

Prerequisits

Requires:

• Python3.7+
• Clang (dev only)

Getting started

Meliorate comes in two parts:

• meliorate.h which includes the meliorate_run function for running tests and other useful parameters for customising test execution.
• meliorateapp which is the code generator.

meliorate.h should be included into you project by adding a compiler include flag (-I) that points to the include directory (and not the include/meliorate directory).

The meliorateapp can be installed from PyPi.

pip install meliorate

Using Meliorate

Write some test functions:

#include "meliorate/meliorate.h"

void test_that_something_is_true()
{
    // code goes here.
}

// Not extracted as a test function because the function name
// does not begin with "test".
int not_a_test_function()
{
    return 0;
}

void test_that_error_is_thrown()
{
    throw std::runtime_error("Something went wrong.");
}


void test_that_the_result_is_42()
{
    // code goes here.
}

// Not extracted as a test function because the function is static.
static void test_that_something_is_false()
{
    // code goes here.
}

Add the meliorate_run function to main:

#include "meliorate/meliorate.h"

int main()
{
    meliorate_stop_on_error = false;
    return meliorate_run<std::exception>();
}

Meliorate assumes your assertion library will use exceptions from the standard library by default (hence why meliorate_run is parameterized with std::exception). To use a custom assertion library, see the Customising Assertions section for more information.

Run the meliorateapp on the test directory:

meliorateapp <path/to/test/directory>

Check that meliorate_gen.cpp is created in the test directory.

Finally, compile and run you test program as normal, remembering to add meliorate_gen.cpp to your build process.

The output will look something like:

[RUN     ] test_that_something_is_true
[  PASSED]
[RUN     ] test_that_error_is_thrown
Something went wrong.
[  FAILED]
[RUN     ] test_that_the_result_is_42
[  PASSED]
1 tests FAILED out of 3

You can force test execution to stop when an error occurs by setting meliorate_stop_on_error variable to true prior to calling the meliorate_run function.

Customising Assertions

Meliorate does not provide any assertions, but by default assumes that the assertion library will use exceptions from the standard library. Should you wish to use another library, such as snowhouse, follow the instructions below:

Provide a specialisation for the meliorate_handle_exception function. This function handles the printing of the exception when an error occurs. By default the function looks like:

template <typename T>
void meliorate_handle_exception(T const& exception)
{
    std::cerr << exception.what() << std::endl;
}

Provide the specialisation like so:

template <typename T>
void meliorate_handle_exception(snowhouse::AssertionException const& exception)
{
    std::cerr << ex.GetMessage() << std::endl;
}

Then set the template parameter for the meliorate_run function:

#include "meliorate/meliorate.h"

int main()
{
    meliorate_stop_on_error = false;
    return meliorate_run<snowhouse::AssertionException>();
}