Mocking¶
cester supports mocking function. The mock feature currently works on GCC compiler only because of the use of the –wrap option which is not supported on MAC OSX and might not be available in other compilers.
The following macros are use for mocking
Mocking a simple function¶
The macro CESTER_MOCK_SIMPLE_FUNCTION can be used to mock a function to return a value. The macro simply wrap the function to return the third parameter when invoked.
Example:
The following test mock a function that accepts no parameter and return a value.
originals.c
int multiply_by() {
return 2;
}
int multiply_a_number(int a) {
return a * multiply_by() ;
}
test_mock.c
#include <exotic/cester.h>
#include "originals.c"
CESTER_MOCK_SIMPLE_FUNCTION(multiply_by(void), int, 5)
CESTER_TEST(check_mocked_function, test_instance,
cester_assert_equal(multiply_a_number(2), 10);
)
Compile your test file with the –wrap option e.g. in the example above the function multiply_by was mocked so the option -Wl,–wrap=multiply_by is supplied during compilation.
gcc test_mock.c -I. -Wl,--wrap=multiply_by -o test_mock
./test_mock
+ (0.00s) check mocked function
Ran 1 test(s) in 0.00 Seconds
Synthesis: SUCCESS Tests: 1 | Passing: 1 | Failing: 0
In the example above the function multiply_by was mocked to return 5 instead of 2, without mocking it the test will fail because multiply_a_number(2) will return 4 instead of 10.
Mocking a function¶
The macro CESTER_MOCK_FUNCTION can be used to mock a function to with a body. Compare to the CESTER_MOCK_SIMPLE_FUNCTION macro this macro can wrap a function that returns or does not return a value.
Example:
The following test mock a function that accepts 2 parameters a pointer to integer and another integer, then return the power of the first parameter.
originals.c
int power_of(int* num1, int num2) {
return *num1 * num2;
}
In the function above the returned value is not correct as it does not return the actual power of the num1 pointer. in our test we will mock the function to properly calculates the power of the num1 pointer.
test_mock.c
#include <exotic/cester.h>
#include "originals.c"
CESTER_MOCK_FUNCTION(power_of(int* num1, int num2), int,
int return_val = *num1;
while (num2-->1) {
return_val *= *num1;
}
return return_val;
)
CESTER_TEST(check_mocked_function, test_instance,
int num = 2;
cester_assert_equal(power_of(&num, 3), 8);
)
Compile your test file with the –wrap option e.g. in the example above the function power_of was mocked so the option -Wl,–wrap=power_of is supplied during compilation.
gcc test_mock.c -I. -Wl,--wrap=power_of -o test_mock
./test_mock
+ (0.00s) check mocked function
Ran 1 test(s) in 0.001000 Seconds
Synthesis: SUCCESS Tested: 1 | Passing: 1 | Failing: 0
To disable mocking in a test without deleting your mock code you can chose not to compile the test with the -Wl,–wrap option or you can define CESTER_NO_MOCK anywhere in the code.
Warning
Static functions cannot be mocked in cester.