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/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file assert_module_test.c
* @brief Example demonstrating expect_assert_failure() with cmocka
*
* This test suite demonstrates a powerful cmocka feature: testing that
* functions correctly assert on invalid input using expect_assert_failure().
*
* Key concepts demonstrated:
* 1. Testing code that uses assert() without crashing the test program
* 2. Using expect_assert_failure() to verify assertions fire correctly
* 3. Distinguishing between assert() and runtime if-checks in tests
*
* This example intentionally includes both passing and failing tests to
* show the different behaviors.
*
* NOTE: This test suite is designed to have FAILING tests to demonstrate
* what happens when assertions don't fire as expected.
*/
#include <cmocka.h>
#include "assert_module.h"
extern void increment_value(int *const value);
/**
* @brief Test increment_value() without expect_assert_failure
*
* This test FAILS because:
* - increment_value(NULL) triggers assert(value)
* - Without expect_assert_failure(), the assertion is treated as a failure
* - cmocka catches the assertion and reports it as a test failure
*
* This demonstrates what happens when you call a function that asserts
* without wrapping it in expect_assert_failure().
*/
static void increment_value_fail(void **state)
{
(void)state; /* unused */
/* BUG: Calling function that asserts without expect_assert_failure()
* This will FAIL because the assert() fires but wasn't expected.
*/
increment_value(NULL);
}
/**
* @brief Test that increment_value() correctly asserts on NULL
*
* This test PASSES because:
* - expect_assert_failure() tells cmocka to expect an assertion
* - increment_value(NULL) triggers assert(value) as expected
* - The assertion is caught and treated as success
*
* This is the correct way to test that a function validates input
* using assertions.
*/
static void increment_value_assert(void **state)
{
(void)state; /* unused */
/* expect_assert_failure() wraps the call and expects assert() to fire.
* This test PASSES because increment_value() does assert on NULL.
*/
expect_assert_failure(increment_value(NULL));
}
/**
* @brief Test decrement_value() with expect_assert_failure
*
* This test FAILS because:
* - expect_assert_failure() expects an assertion to fire
* - decrement_value() uses an if-check, not assert()
* - No assertion fires, so the expectation is not met
*
* This demonstrates the difference between assert() and runtime checks:
* - increment_value() uses assert() - testable with expect_assert_failure()
* - decrement_value() uses if-check - not detectable by expect_assert_failure()
*
* Key lesson: expect_assert_failure() only works with actual assert() calls,
* not with runtime if-checks or other validation methods.
*/
static void decrement_value_fail(void **state)
{
(void)state; /* unused */
/* BUG: This test will FAIL!
* expect_assert_failure() expects an assert() to fire, but
* decrement_value() uses an if-check instead of assert().
* No assertion fires, so the test fails.
*/
expect_assert_failure(decrement_value(NULL));
}
int main(void)
{
const struct CMUnitTest tests[] = {
cmocka_unit_test(increment_value_fail),
cmocka_unit_test(increment_value_assert),
cmocka_unit_test(decrement_value_fail),
};
return cmocka_run_group_tests(tests, NULL, NULL);
}
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