ATF-C-API(3)

NAME
ATF_CHECK, ATF_CHECK_EQUAL, ATF_TC, ATF_TC_BODY, ATF_TC_BODY_NAME, ATF_TC_CLEANUP, ATF_TC_CLEANUP_NAME, ATF_TC_HEAD, ATF_TC_HEAD_NAME, ATF_TC_NAME, ATF_TC_WITH_CLEANUP, ATF_TP_ADD_TC, ATF_TP_ADD_TCS, atf_no_error, atf_tc_fail, atf_tc_pass, atf_tc_skip - C API to write ATF-based test programs

SYNOPSIS
#include <atf-c.h>
ATF_CHECK(expression);
ATF_CHECK_EQUAL(expression_1, expression_2);
ATF_TC(name);
ATF_TC_BODY(name);
ATF_TC_BODY_NAME(name);
ATF_TC_CLEANUP(name);
ATF_TC_CLEANUP_NAME(name);
ATF_TC_HEAD(name);
ATF_TC_HEAD_NAME(name);
ATF_TC_NAME(name);
ATF_TC_WITH_CLEANUP(name);
ATF_TP_ADD_TC(tp_name);
ATF_TP_ADD_TCS(tp_name, tc_name);
atf_no_error();
atf_tc_fail(reason);
atf_tc_pass();
atf_tc_skip(reason);

DESCRIPTION
The ATF

C-based test programs always follow this template:

    ... C-specific includes go here ...
    #include <atf-c.h>
    ATF_TC(tc1);
    ATF_TC_HEAD(tc1)
    {
        ... first test case's header ...
    }
    ATF_TC_BODY(tc1)
    {
        ... first test case's body ...
    }
    ATF_TC_WITH_CLEANUP(tc2);
    ATF_TC_HEAD(tc2)
    {
        ... second test case's header ...
    }
    ATF_TC_BODY(tc2)
    {
        ... second test case's body ...
    }
    ATF_TC_CLEANUP(tc2)
    {
        ... second test case's cleanup ...
    }
    ... additional test cases ...
    ATF_TP_ADD_TCS(tp, tcs)
    {
        ATF_TP_ADD_TC(tcs, tc1)
        ATF_TP_ADD_TC(tcs, tc2)
        ... add additional test cases ...
        return atf_no_error();
    }

  Definition of test cases
Test cases have an identifier and are composed of three different parts: the header, the body and an optional cleanup routine, all of which are described in atf-test-case(8). To define test cases, one can use the ATF_TC() or the ATF_TC_WITH_CLEANUP() macros, which take a single parameter specifiying the test case's name. The former does not allow the specification of a cleanup routine for the test case while the latter does. It is important to note that these do not set the test case up for execution when the program is run. In order to do so, a later registration is needed with the ATF_TP_ADD_TC() macro detailed in Program initialization.

Later on, one must define the three parts of the body by means of three functions. Their headers are given by the ATF_TC_HEAD(), ATF_TC_BODY() and ATF_TC_CLEANUP() macros, all of which take the test case name provided to the ATF_TC() or ATF_TC_WITH_CLEANUP() macros. Following each of these, a block of code is expected, surrounded by the opening and closing brackets.

  Program initialization
The library provides a way to easily define the test program's main() function. You should never define one on your own, but rely on the library to do it for you. This is done by using the ATF_TP_ADD_TCS() macro, which is passed the name of the object that will hold the test cases; i.e. the test program instance. This name can be whatever you want as long as it is a valid variable identifier.

After the macro, you are supposed to provide the body of a function, which should only use the ATF_TP_ADD_TC() macro to register the test cases the test program will execute and return a success error code. The first parameter of this macro matches the name you provided in the former call. The success status can be returned using the atf_no_error() function.

  Header definitions
The test case's header can define the meta-data by using the atf_tc_set_md_var() method, which takes two parameters: the first one specifies the meta-data variable to be set and the second one specifies its value. Both of them are strings.

  Configuration variables
The test case has read-only access to the current configuration variables by means of the bool atf_tc_has_config_var() and the const char * atf_tc_get_config_var() methods, which can be called in any of the three parts of a test case.

  Access to the source directory
It is possible to get the path to the test case's source directory from any of its three components by querying the ‘srcdir’ configuration variable.

  Requiring programs
Aside from the require.progs meta-data variable available in the header only, one can also check for additional programs in the test case's body by using the atf_tc_require_prog() function, which takes the base name or full path of a single binary. Relative paths are forbidden. If it is not found, the test case will be automatically skipped.

  Test case finalization
The test case finalizes either when the body reaches its end, at which point the test is assumed to have passed, or at any explicit call to atf_tc_pass(), atf_tc_fail() or atf_tc_skip(). These three functions terminate the execution of the test case immediately. The cleanup routine will be processed afterwards in a completely automated way, regardless of the test case's termination reason.

atf_tc_pass() does not take any parameters. atf_tc_fail() and atf_tc_skip() take a single string that describes why the test case failed or was skipped, respectively. It is very important to provide a clear error message in both cases so that the user can quickly know why the test did not pass.

  Helper macros for common checks
The library provides several macros that are very handy in multiple situations. These basically check some condition after executing a given statement or processing a given expression and, if the condition is not met, they automatically call atf_tc_fail() with an appropriate error message.

ATF_CHECK() takes an expression and raises a failure if it evaluates to false.

ATF_CHECK_EQUAL() takes two expressions and raises a failure if the two do not evaluate to the same exact value.

EXAMPLES
The following shows a complete test program with a single test case that validates the addition operator:

    #include <atf-c.h>
    ATF_TC(addition);
    ATF_TC_HEAD(addition)
    {
        atf_tc_set_md_var("descr", "Sample tests for the addition operator");
    }
    ATF_TC_BODY(addition)
    {
        ATF_CHECK_EQUAL(0 + 0, 0);
        ATF_CHECK_EQUAL(0 + 1, 1);
        ATF_CHECK_EQUAL(1 + 0, 1);
        ATF_CHECK_EQUAL(1 + 1, 2);
        ATF_CHECK_EQUAL(100 + 200, 300);
    }
    ATF_TP_ADD_TCS(tp)
    {
        ATF_TP_ADD_TC(tp, addition);
        return atf_no_error();
    }

SEE ALSO
atf-test-program(1), atf(7), atf-test-case(8)