How do I reset state of static variables inside functions called by multiple tests? about unity HOT 3 CLOSED

A trick is similar to how we tell people to use STATIC:

#ifdef TEST
#define STATIC
#else
#define STATIC static
#endif

This can be used to give test access to static variables, like so:

STATIC int privateInteger = 0;

Your case is similar, except we're going to basically move the variable out of the function for testing only:

#include <stdio.h>
#include "ProductionCode.h"

#ifdef TEST
int x = 0;
#endif

int foo()
{
    #ifndef TEST
    static int x = 0;
    #endif
    x++;
    printf("x=%u\n", x);
    return x;
}

You now have access to directly effect x:

#include "ProductionCode.h"
#include "unity.h"

extern int x;

void setUp(void)
{
   x = 0;
}

void tearDown(void)
{
}

void test_foo_shouldEqualOne_A(void)
{
    TEST_ASSERT_EQUAL(1, foo());
}

void test_foo_shouldEqualOne_B(void)
{
    TEST_ASSERT_EQUAL(1, foo());
}

from unity.

Thanks!

I found similar way: exposing pointer to the variable to global variable (valid after function runs first).

test/TestProductionCode.c

#include "ProductionCode.h"
#include "unity.h"

extern int* foo_static_x;

void setUp(void)
{
    if (foo_static_x != NULL) 
    {
        *foo_static_x = 0;
    }
}

void tearDown(void)
{
}

void test_foo_shouldEqualOne_A(void)
{
    TEST_ASSERT_EQUAL(1, foo());
}

void test_foo_shouldEqualOne_B(void)
{
    TEST_ASSERT_EQUAL(1, foo());
}

src/ProductionCode.c

#include <stdio.h>
#include "ProductionCode.h"

#ifdef UNIT_TESTS
int* foo_static_x = NULL;
#endif

int foo(void)
{
    static int x = 0;
    #ifdef UNIT_TESTS
    foo_static_x = &x;
    #endif
    x++;
    printf("x=%u\n", x);
    return x;
}

It works:

./test1.out
x=1
test/TestProductionCode.c:19:test_foo_shouldEqualOne_A:PASS
x=1
test/TestProductionCode.c:24:test_foo_shouldEqualOne_B:PASS

Could you share your opinion @mvandervoord ?

I guess there is a small disadvantage of this approach: not being able to set the variable to custom value for the very first test - but as for resetting it's perfectly fine. Advantage is I can have multiple functions with multiple static variables inside of the same name.

from unity.

That option makes sense to me.

Also, with your version, your first test could actually choose to verify that the pointer isn't null AND that it's set to exactly 1 after calling it the function for the first time.

from unity.