Mock的基本概念和方法(续)

来源：互联网发布：软件系统项目实施方案编辑：程序博客网时间：2024/04/25 13:12

本博客（http://blog.csdn.net/livelylittlefish）贴出作者（三二一@小鱼）相关研究、学习内容所做的笔记，欢迎广大朋友指正！

Content

0. 序

1. 平台

2. 第三方库

3.如何使用CMock和Unity？

3.1 修改业务代码

3.2 编写单元测试

3.3如何Mock并测试？

(1)生成mock文件

(2)生成单元测试runner

(3)拷贝或修改生成的mock文件

(4) build

(5) 讨论

4. 总结

Reference

Appendix 1: Cmock installation

Appendix 2: Unity installation

Appendix 3: Ruby installation

Appendix 4: Mockyour_file.c

Appendix 5: my_business_runner.c

0.序

在Mock的基本概念和方法一文中，笔者在结尾提出了一个问题，有没有一种比较好的方法或者工具，能自动产生一些文件或者目录，供测试使用？

有，一定有，因为，这个世界从来不缺聪明的发明人。

那么，本文仍以Mock的基本概念和方法一文中的例子为例，重点讲述使用Cmock、Unity等工具进行单元测试的方法。

注：本文的实验，CUnit不是必须的。

1.平台

Cygwin, or Linux

工作目录:

Linux : # cd /usr/src/cmock_sample

Cygwin: $ cd /usr/src/cmock_sample

2.第三方库

本文实验用到的第三方库分别为：

cmock_2_0_204.zip：http://sourceforge.net/projects/cmock/files/cmock/cmock2.0/cmock_2_0_204.zip

unity_2_0_113.zip：http://sourceforge.net/projects/unity/files/unity/unity2.0/unity_2_0_113.zip

ruby-1.9-stable.tar.gz：http://ftp.ruby-lang.org/pub/ruby/ruby-1.9-stable.tar.gz

实际上，cmock_2_0_204.zip在其vendor目录中包含了Unity。

3.如何使用CMock和Unity？

以下将以cygwin平台为例。

3.1修改业务代码

该例子中的业务代码文件：my_business.c

为例使用CMock和Unity工具，需要修改my_business.c文件，将其中的main函数删除，并增加my_business.h文件。如下。

/*
* my bussiness.h
*/

int read_file();

my_business.c文件内容。

/*
* my bussiness
*/

#include "my_business.h"
#include

int read_file()
{
    FILE* fp = your_file_open("data.txt");
    //assert(fp != 0);

    /*
     * here my business start, for example, read data from the file.
     * for test, only print the fp.
     */
    printf("%s, %d: file handle = 0x%x/n", __FUNCTION__, __LINE__, (unsigned int)fp);

    your_file_close(fp);
    return 0;
}

注：实际上，或许某些场合不需要该头文件，但为了本文说明问题的需要，提供该文件。后面的Unity工具将根据该文件自动生成mock文件。

3.2编写单元测试

要对业务代码做单元测试，应该事先编写好单元测试代码，文件为my_business_unittest.c，如下。

/*
* my bussiness unittest
*/

#include "my_business.h"
#include "unity.h"

void setUp(void)
{
}

void tearDown(void)
{
}

void test_read_file()
{
TEST_ASSERT_EQUAL(0, read_file());
}

void test_read_file2()
{
TEST_ASSERT_NOT_EQUAL(1, read_file());
}

3.3如何Mock并测试？

(1)生成mock文件

业务代码my_business.h/.c依赖your_file.h/.c，根据Cmock/Unity框架，要根据your_file.h自动生成mock文件。Cmock框架提供了该自动生成的功能，是用ruby写的scripts，在./cmock/lib目录下，在运行这些脚本时，使用ruby命令，因此需要第三方库ruby。完成该自动生成功能的脚本是./cmock/lib/cmock.rb，可以处理1个或多个.h文件。

$ mkdir mocks //默认情况下，生成的mock文件保存在该目录，故需事先建立好
$ ruby /usr/src/cmock/lib/cmock.rb your_file.h //运行该脚本生成mock文件
Creating mock for your_file...
$ cd mocks
$ ls
Mockyour_file.c Mockyour_file.h //自动生成的mock文件
$ cd ..

此处，笔者仅提供Mockyour_file.h的内容，Mockyour_file.c文件太大，请参考附录。

/* AUTOGENERATED FILE. DO NOT EDIT. */
#ifndef _MOCKYOUR_FILE_H
#define _MOCKYOUR_FILE_H

#include "your_file.h"

void Mockyour_file_Init(void);
void Mockyour_file_Destroy(void);
void Mockyour_file_Verify(void);

#define your_file_open_ExpectAndReturn(fname, cmock_retval) your_file_open_CMockExpectAndReturn(__LINE__, fname, cmock_retval)
void your_file_open_CMockExpectAndReturn(UNITY_LINE_TYPE cmock_line, char* fname, FILE* cmock_to_return);
#define your_file_close_Expect(fp) your_file_close_CMockExpect(__LINE__, fp)
void your_file_close_CMockExpect(UNITY_LINE_TYPE cmock_line, FILE* fp);

#endif

(2)生成单元测试runner

Unity工具提供了根据单元测试文件自动生成runner文件的功能，该runner文件中包含main()函数，这就是单元测试程序启动的入口。这也是为什么要修改my_business.c，将其中的main()删除的原因。

What a great idea!Ruby真的是一门很好的语言，是时候学习了。

这将节省开发人员很多的时间，使开发人员将精力集中在单元测试本身和设计测试用例上。

$ ruby /usr/src/unity/auto/generate_test_runner.rb my_business_unittest.c my_business_runner.c
$ ls
data.txt makefile my_business.c my_business_runner.c your_file.c
make.bat mocks my_business.h my_business_unittest.c your_file.h

(3)拷贝或修改生成的mock文件

因为生成的mock文件放在mocks目录，且在Mockyour_file.h中包含了your_file.h，但mocks目录中并没有your_file.h文件，而是在上一级目录中，因此需要将其拷贝到上一级目录，或者修改Mockyour_file.h文件中包含your_file.h的路径。笔者选择拷贝。

$ cp mocks/Mockyour_file.h Mockyour_file.h
$ cp mocks/Mockyour_file.c Mockyour_file.c

自此，要进行单元测试所需的.h/.c文件全部建立，小结一下，看看有哪些文件。

你的代码文件：your_file.h/.c (该文件在测试时不再使用)

mocked文件：Mockyour_file.h/.c (在测试时要依赖该文件)

业务代码文件：my_business.h/.c

业务测试文件：my_business_unittest.c

测试运行文件：my_business_runner.c (main()函数即在其中)

(4)build

本文的实验，笔者编写了makefile(Linux平台/Cygwin环境)或者make.bat(win32平台)，让build更加快速和可控。

使用CMokc和Unity进行单元测试和Mock，一定会依赖CMock和Unity，因此这两个工具的源代码cmock.c和unity.c也一定要编译到并链接到目标文件。那么对于CMock和Unity，我们需要或者依赖哪些文件呢？

不要被CMock和Unity的内容吓到！虽然其中有很多目录和文件，但其核心(框架)文件很少，而这些核心文件正是build需要的。

CMock: ./cmock/src/cmock.c //CMock的core文件在./cmock/src目录

./cmock/src/cmock.h

Unity: ./unity/src/unity.c //Unity的core文件在./unity/src目录

./unity/src/unity.h

./unity/src/unity_internals.h

综上，编写的makefile文件和make.bat文件如下。makefile文件适用于cygwin和Linux平台。

CXX = gcc
CXXFLAGS += -g -Wall -Wextra

TESTS = my_business

CMOCK_DIR = /usr/src/cmock
CMOCK_SRC = $(CMOCK_DIR)/src
UNITY_DIR = /usr/src/unity
UNITY_SRC = $(UNITY_DIR)/src

ifeq ($(OS), Windows_NT)
TARGET_EXTENSION=.exe
else
TARGET_EXTENSION=.out
endif

TARGET = $(TESTS)$(TARGET_EXTENSION)

CLEANUP = rm -f $(TARGET) *.o

all : $(TARGET)

clean :
$(CLEANUP)

unity.o: $(UNITY_SRC)/unity.c
$(CXX) $(CXXFLAGS) -I$(UNITY_SRC) -c $^

cmock.o: $(CMOCK_SRC)/cmock.c
$(CXX) $(CXXFLAGS) -I$(CMOCK_SRC) -I$(UNITY_SRC) -c $^

mockyour_file.o: mockyour_file.c
$(CXX) $(CXXFLAGS) -I$(CMOCK_SRC) -I$(UNITY_SRC) -c $^

my_business.o: my_business.c
$(CXX) $(CXXFLAGS) -c $^

my_business_unittest.o: my_business_unittest.c
$(CXX) $(CXXFLAGS) -I$(UNITY_SRC) -c $^

my_business_runner.o: my_business_runner.c
$(CXX) $(CXXFLAGS) -I$(UNITY_SRC) -c $^

$(TARGET): unity.o cmock.o mockyour_file.o my_business.o my_business_unittest.o my_business_runner.o
$(CXX) $(CXXFLAGS) $^ -o $@

(5)讨论

这真的是一种前无古人的方法，CMock能自动生成mock文件，让你进行单元测试；Unity能自动生成单元测试runner，让你的单元测试跑起来。CMock和Unity的出现，为广大开发者节省了宝贵的时间，使你的精力集中于单元测试本身和测试用例的设计上。

4.总结

本文，笔者以一个例子讨论了使用CMock和Unity进行mock和单元测试的方法和过程，主要关注如何使用这两个工具并build，build时，要注意CMock和Unity的cmock.c和unity.c也要编译并链接到目标文件。

本文重点如下。

生成mock文件
生成单元测试runner
build

广大软件开发者们，如果要做C项目的单元测试，尤其是嵌入式软件的单元测试，那就去大胆尝试CMock和Unity吧！

Reference

CMock简介：CMock Summary.pdf

Unity简介：Unity Summary.pdf

CMock设计原理：Functionality_and_Design_of_the_CMock_Framework.pdf

如何mocking嵌入式软件：Mocking the Embedded World - Test-Driven Development, Continuous Integration, and Design Patterns.pdf

http://sourceforge.net/apps/trac/cmock

http://sourceforge.net/apps/trac/unity

http://sourceforge.net/projects/unity/forums/forum/770030/topic/4067272

http://sourceforge.net/projects/unity/forums/forum/770030/topic/3795145

http://sourceforge.net/apps/trac/cmock/wiki/EclipseIde

http://sourceforge.net/apps/mediawiki/unity/index.php?title=Eclipse_IDE_Integration

http://en.wikipedia.org/wiki/List_of_unit_testing_frameworks (各种单元测试工具比较)

http://sourceforge.net/projects/unity/forums/forum/770030/topic/4067272 (Cmock和Unity的关系)

http://meekrosoft.wordpress.com/2010/01/29/unit-test-embedded-software-in-3-easy-steps (嵌入式软件单元测试的3个步骤)

http://www.lulu.com/product/paperback/embedded-testing-with-unity-and-cmock/14408590?productTrackingContext=search_results/search_shelf/center/1, By Mark VanderVoord.

Appendix 1: Cmock installation

# cd /usr/src

# wget http://sourceforge.net/projects/cmock/files/cmock/cmock2.0/cmock_2_0_204.zip

# unzip -x cmock_2_0_204.zip

# cd cmock

编译需要ruby的构建系统rake，有待研究。

Appendix 2: Unity installation

# cd /usr/src

# wget http://sourceforge.net/projects/unity/files/unity/unity2.0/unity_2_0_113.zip

# unzip -x unity_2_0_113.zip

# cd unity

# make

# cd examples

# make

Appendix 3: Ruby installation

$ cd /usr/src

$ wget http://ftp.ruby-lang.org/pub/ruby/ruby-1.9-stable.tar.gz

$ tar.exe -zxvf ruby-1.9-stable.tar.gz

$ cd ruby-1.9.2-p180

$ ./configure && make && make install

Appendix 4: Mockyour_file.c

/* AUTOGENERATED FILE. DO NOT EDIT. */#include <string.h>#include <stdlib.h>#include <setjmp.h>#include "unity.h"#include "cmock.h"#include "Mockyour_file.h"typedef struct _CMOCK_your_file_open_CALL_INSTANCE{ UNITY_LINE_TYPE LineNumber; FILE* ReturnVal; char* Expected_fname;} CMOCK_your_file_open_CALL_INSTANCE;typedef struct _CMOCK_your_file_close_CALL_INSTANCE{ UNITY_LINE_TYPE LineNumber; FILE* Expected_fp;} CMOCK_your_file_close_CALL_INSTANCE;static struct Mockyour_fileInstance{ CMOCK_MEM_INDEX_TYPE your_file_open_CallInstance; CMOCK_MEM_INDEX_TYPE your_file_close_CallInstance;} Mock;extern jmp_buf AbortFrame;void Mockyour_file_Verify(void){ UNITY_LINE_TYPE cmock_line = TEST_LINE_NUM; UNITY_TEST_ASSERT(CMOCK_GUTS_NONE == Mock.your_file_open_CallInstance, cmock_line, "Function 'your_file_open' called less times than expected."); UNITY_TEST_ASSERT(CMOCK_GUTS_NONE == Mock.your_file_close_CallInstance, cmock_line, "Function 'your_file_close' called less times than expected.");}void Mockyour_file_Init(void){ Mockyour_file_Destroy();}void Mockyour_file_Destroy(void){ CMock_Guts_MemFreeAll(); memset(&Mock, 0, sizeof(Mock));}FILE* your_file_open(char* fname){ UNITY_LINE_TYPE cmock_line = TEST_LINE_NUM; CMOCK_your_file_open_CALL_INSTANCE* cmock_call_instance = (CMOCK_your_file_open_CALL_INSTANCE*)CMock_Guts_GetAddressFor(Mock.your_file_open_CallInstance);return 0x9048120; Mock.your_file_open_CallInstance = CMock_Guts_MemNext(Mock.your_file_open_CallInstance); UNITY_TEST_ASSERT_NOT_NULL(cmock_call_instance, cmock_line, "Function 'your_file_open' called more times than expected."); cmock_line = cmock_call_instance->LineNumber; UNITY_TEST_ASSERT_EQUAL_STRING(cmock_call_instance->Expected_fname, fname, cmock_line, "Function 'your_file_open' called with unexpected value for argument 'fname'."); return cmock_call_instance->ReturnVal;}void CMockExpectParameters_your_file_open(CMOCK_your_file_open_CALL_INSTANCE* cmock_call_instance, char* fname){ cmock_call_instance->Expected_fname = fname;}void your_file_open_CMockExpectAndReturn(UNITY_LINE_TYPE cmock_line, char* fname, FILE* cmock_to_return){ CMOCK_MEM_INDEX_TYPE cmock_guts_index = CMock_Guts_MemNew(sizeof(CMOCK_your_file_open_CALL_INSTANCE)); CMOCK_your_file_open_CALL_INSTANCE* cmock_call_instance = (CMOCK_your_file_open_CALL_INSTANCE*)CMock_Guts_GetAddressFor(cmock_guts_index); UNITY_TEST_ASSERT_NOT_NULL(cmock_call_instance, cmock_line, "CMock has run out of memory. Please allocate more."); Mock.your_file_open_CallInstance = CMock_Guts_MemChain(Mock.your_file_open_CallInstance, cmock_guts_index); cmock_call_instance->LineNumber = cmock_line; CMockExpectParameters_your_file_open(cmock_call_instance, fname); cmock_call_instance->ReturnVal = cmock_to_return;}void your_file_close(FILE* fp){ UNITY_LINE_TYPE cmock_line = TEST_LINE_NUM; CMOCK_your_file_close_CALL_INSTANCE* cmock_call_instance = (CMOCK_your_file_close_CALL_INSTANCE*)CMock_Guts_GetAddressFor(Mock.your_file_close_CallInstance); Mock.your_file_close_CallInstance = CMock_Guts_MemNext(Mock.your_file_close_CallInstance); UNITY_TEST_ASSERT_NOT_NULL(cmock_call_instance, cmock_line, "Function 'your_file_close' called more times than expected."); cmock_line = cmock_call_instance->LineNumber; UNITY_TEST_ASSERT_EQUAL_MEMORY((void*)(cmock_call_instance->Expected_fp), (void*)(fp), sizeof(FILE), cmock_line, "Function 'your_file_close' called with unexpected value for argument 'fp'.");}void CMockExpectParameters_your_file_close(CMOCK_your_file_close_CALL_INSTANCE* cmock_call_instance, FILE* fp){ cmock_call_instance->Expected_fp = fp;}void your_file_close_CMockExpect(UNITY_LINE_TYPE cmock_line, FILE* fp){ CMOCK_MEM_INDEX_TYPE cmock_guts_index = CMock_Guts_MemNew(sizeof(CMOCK_your_file_close_CALL_INSTANCE)); CMOCK_your_file_close_CALL_INSTANCE* cmock_call_instance = (CMOCK_your_file_close_CALL_INSTANCE*)CMock_Guts_GetAddressFor(cmock_guts_index); UNITY_TEST_ASSERT_NOT_NULL(cmock_call_instance, cmock_line, "CMock has run out of memory. Please allocate more."); Mock.your_file_close_CallInstance = CMock_Guts_MemChain(Mock.your_file_close_CallInstance, cmock_guts_index); cmock_call_instance->LineNumber = cmock_line; CMockExpectParameters_your_file_close(cmock_call_instance, fp);}

Appendix 5: my_business_runner.c

/* AUTOGENERATED FILE. DO NOT EDIT. *///=======Test Runner Used To Run Each Test Below=====#define RUN_TEST(TestFunc, TestLineNum) /{ / Unity.CurrentTestName = #TestFunc; / Unity.CurrentTestLineNumber = TestLineNum; / Unity.NumberOfTests++; / if (TEST_PROTECT()) / { / setUp(); / TestFunc(); / } / if (TEST_PROTECT() && !TEST_IS_IGNORED) / { / tearDown(); / } / UnityConcludeTest(); /}//=======Automagically Detected Files To Include=====#include "unity.h"#include <setjmp.h>#include <stdio.h>//=======External Functions This Runner Calls=====extern void setUp(void);extern void tearDown(void);extern void test_read_file();extern void test_read_file2();//=======Test Reset Option=====void resetTest(){ tearDown(); setUp();}//=======MAIN=====int main(void){ Unity.TestFile = "my_business_unittest.c"; UnityBegin(); RUN_TEST(test_read_file, 16); RUN_TEST(test_read_file2, 21); return (UnityEnd());}

Technorati 标签: 单元测试；Mock；CMock；Unity