单元:对于C语言来说,单元即函数。
C语言单元测试:对C语言中的功能函数进行正确性、效能等方面的测试。
CUnit:一个用于C语言单元测试的软件,下载地址为http://sourceforge.net/projects/cunit/,相关的例子可以在http://cunit.sourceforge.net/example.html找到。
1、安装CUnit,环境为Linux
./configure --prefix=/usr/local # 指定安装路径为/usr/local
make
make install
2、CUnit基本框架
Test Registry
|
------------------------------
| |
TestSuite '1' . . . . TestSuite 'N'
| |
--------------- ---------------
| | | |
Test '11' ... Test '1M' Test 'N1' ... Test 'NM'
一次测试(Test Registry)可以运行多个测试包(Test Suite),而每个测试包可以包括多个测试用例(Test Case)。每个测试用例又包含一个或者多个断言类的语句。具体到程序的结构上,一次测试下辖多个Test Suite,它对应于程序中各个独立模块;一个Suite管理多个Test Case,它对应于模块内部函数实现。每个Suite可以含有setup和teardown函数,分别在执行suite的前后调用。
3、CUnit测试接口模式CUnit共有4种测试接口模式,为用户提供交互和测试结果,如下
其中方式2比较常用,就是通常的控制台交互方式。
4、CUnit用于C语言测试的流程
参考CUnit安装软件中的doc文件,CUnit测试C函数单元分为6步:
以下的测试源代码可以在http://cunit.sourceforge.net/example.html上找到。
我们这里将代码中的
CU_basic_run_tests();
修改为
CU_console_run_tests();
修改的目的:原来代码中使用“基本方式”作为测试接口模式,现在改成了控制台交互的方式。
基本方式直接执行程序后退出,交互方式有更多的可选择余地,可以看作是基本方式的扩展。
/* * Simple example of a CUnit unit test. * * This program (crudely) demonstrates a very simple "black box" * test of the standard library functions fprintf() and fread(). * It uses suite initialization and cleanup functions to open * and close a common temporary file used by the test functions. * The test functions then write to and read from the temporary * file in the course of testing the library functions. * * The 2 test functions are added to a single CUnit suite, and * then run using the CUnit Basic interface. The output of the * program (on CUnit version 2.0-2) is: * * CUnit : A Unit testing framework for C. * http://cunit.sourceforge.net/ * * Suite: Suite_1 * Test: test of fprintf() ... passed * Test: test of fread() ... passed * * --Run Summary: Type Total Ran Passed Failed * suites 1 1 n/a 0 * tests 2 2 2 0 * asserts 5 5 5 0 */ #include <stdio.h> #include <string.h> #include "CUnit/Basic.h" /* Pointer to the file used by the tests. */ static FILE* temp_file = NULL; /* The suite initialization function. * Opens the temporary file used by the tests. * Returns zero on success, non-zero otherwise. */ int init_suite1(void) { if (NULL == (temp_file = fopen("temp.txt", "w+"))) { return -1; } else { return 0; } } /* The suite cleanup function. * Closes the temporary file used by the tests. * Returns zero on success, non-zero otherwise. */ int clean_suite1(void) { if (0 != fclose(temp_file)) { return -1; } else { temp_file = NULL; return 0; } } /* Simple test of fprintf(). * Writes test data to the temporary file and checks * whether the expected number of bytes were written. */ void testFPRINTF(void) { int i1 = 10; if (NULL != temp_file) { CU_ASSERT(0 == fprintf(temp_file, "")); CU_ASSERT(2 == fprintf(temp_file, "Q\n")); CU_ASSERT(7 == fprintf(temp_file, "i1 = %d", i1)); } } /* Simple test of fread(). * Reads the data previously written by testFPRINTF() * and checks whether the expected characters are present. * Must be run after testFPRINTF(). */ void testFREAD(void) { unsigned char buffer[20]; if (NULL != temp_file) { rewind(temp_file); CU_ASSERT(9 == fread(buffer, sizeof(unsigned char), 20, temp_file)); CU_ASSERT(0 == strncmp(buffer, "Q\ni1 = 10", 9)); } } /* The main() function for setting up and running the tests. * Returns a CUE_SUCCESS on successful running, another * CUnit error code on failure. */ int main() { CU_pSuite pSuite = NULL; /* initialize the CUnit test registry */ if (CUE_SUCCESS != CU_initialize_registry()) return CU_get_error(); /* add a suite to the registry */ pSuite = CU_add_suite("Suite_1", init_suite1, clean_suite1); if (NULL == pSuite) { CU_cleanup_registry(); return CU_get_error(); } /* add the tests to the suite */ /* NOTE - ORDER IS IMPORTANT - MUST TEST fread() AFTER fprintf() */ if ((NULL == CU_add_test(pSuite, "test of fprintf()", testFPRINTF)) || (NULL == CU_add_test(pSuite, "test of fread()", testFREAD))) { CU_cleanup_registry(); return CU_get_error(); } /* Run all tests using the CUnit Basic interface */ CU_console_run_tests(); CU_cleanup_registry(); return CU_get_error(); }
当然,当涉及的测试单元比较多的时候,使用譬如
if ((NULL == CU_add_test(pSuite, "test of fprintf()", testFPRINTF)) || (NULL == CU_add_test(pSuite, "test of fread()", testFREAD)))的测试方法是比较麻烦的。因此还有一种更简便的方法
CU_TestInfo testcase[] = { {"TestFPRINTF: ", TestFPRINTF}, {"TestFREAD: ", TestFREAD}, CU_TEST_INFO_NULL }; CU_SuiteInfo suite[] = { {"Testing func: ", InitSuite, EndSuite, testcase}, CU_SUITE_INFO_NULL }; /* Init registry */ if(CUE_SUCCESS != CU_initialize_registry()) { return CU_get_error(); } /* register suite */ if(CUE_SUCCESS != CU_register_suites(suite)) { return 1; } CU_console_run_tests(); CU_cleanup_registry();
为了能执行上面的程序,我们为程序编写makefile文件,
INC=-I/usr/local/include LIB=-L/usr/local/lib test:test.c gcc test.c -o test -lcunit -static
注意:makefile中要包含CUnit的头文件和库所在的路径,编译时使用-lcunit选项,并使用静态编译(-static)选项。
如下为运行结果,从光标处我们可以选择不同功能。
6、总结及参考
测试过程中,为了通用性,我们将测试代码分为一下几部分组成。
(1)测试单元(函数)源代码
(2)TestSuite.c添加测试包和测试用例
(3)main.c主程序框架,用于注册CUnit和取消注册CUnit
当然,我们也可以把测试单独放在一个文件中就行了。
更多使用细节参考帮助文档。
其它参考:http://blog.csdn.net/colin719/article/details/1420583
http://cunit.sourceforge.net/index.html