CUnit Progammers Guide
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2. Writing CUnit Test Cases

2.1. Test Functions

A CUnit "test" is a C function having the signature:

void test_func(void)

There are no restrictions on the content of a test function, except that it should not modify the CUnit framework (e.g. add suites or tests, modify the test registry, or initiate a test run). A test function may call other functions (which also may not modify the framework). Registering a test will cause it's function to be run when the test is run.

An example test function for a routine that returns the maximum of 2 integers might look like: 


    int maxi(int i1, int i2)
    {
      return (i1 > i2) ? i1 : i2;
    }

    void test_maxi(void)
    {
      CU_ASSERT(maxi(0,2) == 2);
      CU_ASSERT(maxi(0,-2) == 0);
      CU_ASSERT(maxi(2,2) == 2);
    }

2.2. CUnit Assertions

CUnit provides a set of assertions for testing logical conditions. The success or failure of these assertions is tracked by the framework, and can be viewed when a test run is complete.

Each assertion tests a single logical condition, and fails if the condition evaluates to FALSE. Upon failure, the test function continues unless the user chooses the 'xxx_FATAL' version of an assertion. In that case, the test function is aborted and returns immediately. FATAL versions of assertions should be used with caution! There is no opportunity for the test function to clean up after itself once a FATAL assertion fails. The normal suite cleanup function is not affected, however.

There are also special "assertions" for registering a pass or fail with the framework without performing a logical test. These are useful for testing flow of control or other conditions not requiring a logical test: 


    void test_longjmp(void)
    {
      jmp_buf buf;
      int i;

      i = setjmp(buf);
      if (i == 0) {
        run_other_func();
        CU_PASS("run_other_func() succeeded.");
      }
      else
        CU_FAIL("run_other_func() issued longjmp.");
    }

Other functions called by a registered test function may use the CUnit assertions freely. These assertions will be counted for the calling function. They may also use FATAL versions of assertions - failure will abort the original test function and its entire call chain.

The assertions defined by CUnit are:

#include <CUnit/CUnit.h>

CU_ASSERT(int expression)
CU_ASSERT_FATAL(int expression)
CU_TEST(int expression)
CU_TEST_FATAL(int expression) 		Assert that expression is TRUE (non-zero)
CU_ASSERT_TRUE(value)
CU_ASSERT_TRUE_FATAL(value) 		Assert that value is TRUE (non-zero)
CU_ASSERT_FALSE(value)
CU_ASSERT_FALSE_FATAL(value) 		Assert that value is FALSE (zero)
CU_ASSERT_EQUAL(actual, expected)
CU_ASSERT_EQUAL_FATAL(actual, expected) 		Assert that actual = = expected
CU_ASSERT_NOT_EQUAL(actual, expected))
CU_ASSERT_NOT_EQUAL_FATAL(actual, expected) 		Assert that actual != expected
CU_ASSERT_PTR_EQUAL(actual, expected)
CU_ASSERT_PTR_EQUAL_FATAL(actual, expected) 		Assert that pointers actual = = expected
CU_ASSERT_PTR_NOT_EQUAL(actual, expected)
CU_ASSERT_PTR_NOT_EQUAL_FATAL(actual, expected) 		Assert that pointers actual != expected
CU_ASSERT_PTR_NULL(value)
CU_ASSERT_PTR_NULL_FATAL(value) 		Assert that pointer value == NULL
CU_ASSERT_PTR_NOT_NULL(value)
CU_ASSERT_PTR_NOT_NULL_FATAL(value) 		Assert that pointer value != NULL
CU_ASSERT_STRING_EQUAL(actual, expected)
CU_ASSERT_STRING_EQUAL_FATAL(actual, expected) 		Assert that strings actual and expected are equivalent
CU_ASSERT_STRING_NOT_EQUAL(actual, expected)
CU_ASSERT_STRING_NOT_EQUAL_FATAL(actual, expected) 		Assert that strings actual and expected differ
CU_ASSERT_NSTRING_EQUAL(actual, expected, count)
CU_ASSERT_NSTRING_EQUAL_FATAL(actual, expected, count) 		Assert that 1st count chars of actual and expected are the same
CU_ASSERT_NSTRING_NOT_EQUAL(actual, expected, count)
CU_ASSERT_NSTRING_NOT_EQUAL_FATAL(actual, expected, count) 		Assert that 1st count chars of actual and expected differ
CU_ASSERT_DOUBLE_EQUAL(actual, expected, granularity)
CU_ASSERT_DOUBLE_EQUAL_FATAL(actual, expected, granularity) 		Assert that |actual - expected| <= |granularity|
Math library must be linked in for this assertion.
CU_ASSERT_DOUBLE_NOT_EQUAL(actual, expected, granularity)
CU_ASSERT_DOUBLE_NOT_EQUAL_FATAL(actual, expected, granularity) 		Assert that |actual - expected| > |granularity|
Math library must be linked in for this assertion.
CU_PASS(message) Register a passing assertion with the specified message. No logical test is performed.
CU_FAIL(message)
CU_FAIL_FATAL(message) 		Register a failed assertion with the specified message. No logical test is performed.

2.3. Depecated v1 Assertions

The following assertions are deprecated as of version 2. To use these assertions, user code must be compiled with USE_DEPRECATED_CUNIT_NAMES defined. Note that they behave the same as in version 1 (issue a 'return' statement upon failure).

#include <CUnit/CUnit.h>

Deprecated Name Equivalent New Name
ASSERT CU_ASSERT_FATAL
ASSERT_TRUE CU_ASSERT_TRUE_FATAL
ASSERT_FALSE CU_ASSERT_FALSE_FATAL
ASSERT_EQUAL CU_ASSERT_EQUAL_FATAL
ASSERT_NOT_EQUAL CU_ASSERT_NOT_EQUAL_FATAL
ASSERT_PTR_EQUAL CU_ASSERT_PTR_EQUAL_FATAL
ASSERT_PTR_NOT_EQUAL CU_ASSERT_PTR_NOT_EQUAL_FATAL
ASSERT_PTR_NULL CU_ASSERT_PTR_NULL_FATAL
ASSERT_PTR_NOT_NULL CU_ASSERT_PTR_NOT_NULL_FATAL
ASSERT_STRING_EQUAL CU_ASSERT_STRING_EQUAL_FATAL
ASSERT_STRING_NOT_EQUAL CU_ASSERT_STRING_NOT_EQUAL_FATAL
ASSERT_NSTRING_EQUAL CU_ASSERT_NSTRING_EQUAL_FATAL
ASSERT_NSTRING_NOT_EQUAL CU_ASSERT_NSTRING_NOT_EQUAL_FATAL
ASSERT_DOUBLE_EQUAL CU_ASSERT_DOUBLE_EQUAL_FATAL
ASSERT_DOUBLE_NOT_EQUAL CU_ASSERT_DOUBLE_NOT_EQUAL_FATAL

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