Changing the internals

Providing your own main

If you are not satisfied with the default CLI or environment variables, you can define your own main function.

Configuring the test runner

First and foremost, you need to generate the test set; this is done by calling criterion_initialize(). The function returns a struct criterion_test_set *, that you need to pass to criterion_run_all_tests later on.

At the very end of your main, you also need to call criterion_finalize with the test set as parameter to free any ressources initialized by criterion earlier.

You’d usually want to configure the test runner before calling it. Configuration is done by setting fields in a global variable named criterion_options (include criterion/options.h).

Here is an exhaustive list of these fields:

Field Type Description
logging_threshold enum criterion_logging_level The logging level
logger struct criterion_logger * The logger (see below)
always_succeed bool True iff criterion_run_all_tests should always returns 1
use_ascii bool True iff the outputs should use the ASCII charset
fail_fast bool True iff the test runner should abort after the first failure
pattern const char * The pattern of the tests that should be executed

if you want criterion to provide its own default CLI parameters and environment variables handling, you can also call criterion_handle_args(int argc, char *argv[], bool handle_unknown_arg) with the proper argc/argv. handle_unknown_arg, if set to true, is here to tell criterion to print its usage when an unknown CLI parameter is encountered. If you want to add your own parameters, you should set it to false.

The function returns 0 if the main should exit immediately, and 1 if it should continue.

Starting the test runner

The test runner can be called with criterion_run_all_tests. The function returns 0 if one test or more failed, 1 otherwise.

Example main

#include <criterion/criterion.h>

int main(int argc, char *argv[]) {
    struct criterion_test_set *tests = criterion_initialize();

    int result = 0;
    if (criterion_handle_args(argc, argv, true))
        result = !criterion_run_all_tests(tests);

    return result;

Implementing your own logger

In case you are not satisfied by the default logger, you can implement yours. To do so, simply set the logger option to your custom logger.

Each function contained in the structure is called during one of the standard phase of the criterion runner.

For more insight on how to implement this, see other existing loggers in src/log/.