C语言单元测试专家指南(gtest)(一)

为了便于初学者理解,C语言单元测试的方法,写了实例教程.
初学者1个星期就能完成学习,理解并运用.

1. EXPECT_TRUE

基本判定 使用场景: 验证结果为真
对真/假的条件进行判定

终止断言	普通判定	验证
ASSERT_TRUE(条件);	EXPECT_TRUE(条件);	验证条件为真
ASSERT_FALSE(条件);	EXPECT_FALSE(条件);	验证条件为假

测试举例

 运行结果

[ RUN      ] HelloGtest.case_EXPECT_TRUE
Hello Gtest!
[       OK ] HelloGtest.case_EXPECT_TRUE (0 ms)
 命中[ 2 ]总行数[ 2 ]覆盖率[100.0%] 

 2. ASSERT_TRUE

ASSERT_TRUE, 使用场景: 验证结果为真，失败时，程序终止
对真/假的条件进行判定

终止断言	普通判定	验证
ASSERT_TRUE(条件);	EXPECT_TRUE(条件);	验证条件为真
ASSERT_FALSE(条件);	EXPECT_FALSE(条件);	验证条件为假

测试举例

运行结果
 

[ RUN      ] HelloGtest.case_ASSERT_TRUE
case_ASSERT_TRUE.c:10: Failure
Value of: value==32768
  Actual: false
Expected: true
32767+1 is not 32768, which is-32768
[  FAILED  ] HelloGtest.case_ASSERT_TRUE (0 ms)
 命中[ 2 ]总行数[ 2 ]覆盖率[100.0%] 

 3.EXPECT_EQ

EXPECT_EQ 数值比较判定 使用场景: 确认两个数值相等

对数值条件进行比较判定

终止断言	普通判定	验证
ASSERT_EQ(val1, val2);	EXPECT_EQ(val1, val2);	val1 == val2
ASSERT_NE(val1, val2);	EXPECT_NE(val1, val2);	val1 != val2
ASSERT_LT(val1, val2);	EXPECT_LT(val1, val2);	val1 < val2
ASSERT_LE(val1, val2);	EXPECT_LE(val1, val2);	val1 <= val2
ASSERT_GT(val1, val2);	EXPECT_GT(val1, val2);	val1 > val2
ASSERT_GE(val1, val2);	EXPECT_GE(val1, val2);	val1 >= val2

测试举例

运行结果

[ RUN      ] HelloGtest.case_EXPECT_EQ
[       OK ] HelloGtest.case_EXPECT_EQ (0 ms)
 命中[ 4 ]总行数[ 8 ]覆盖率[50.0%] 

 EXPECT_STREQ

字符串比较 使用场景: 字符串比较

Fatal assertion	Nonfatal assertion	Verifies
ASSERT_STREQ(str1,str2);	EXPECT_STREQ(str1,str2);	the two C strings have the same content
ASSERT_STRNE(str1,str2);	EXPECT_STRNE(str1,str2);	the two C strings have different contents
ASSERT_STRCASEEQ(str1,str2);	EXPECT_STRCASEEQ(str1,str2);	the two C strings have the same content, ignoring case
ASSERT_STRCASENE(str1,str2);	EXPECT_STRCASENE(str1,str2);	the two C strings have different contents, ignoring case

 代码举例

 运行结果

[ RUN      ] HelloGtest.case_EXPECT_STREQ
[       OK ] HelloGtest.case_EXPECT_STREQ (0 ms)
 命中[ 3 ]总行数[ 10 ]覆盖率[30.0%] 

EXPECT_FLOAT_EQ

浮点数比较 使用场景: 浮点数比较

浮点数比较特殊，必须使用浮点数宏进行比较

Fatal assertion	Nonfatal assertion	Verifies
ASSERT_FLOAT_EQ(val1, val2);	EXPECT_FLOAT_EQ(val1, val2);	the two float values are almost equal
ASSERT_DOUBLE_EQ(val1, val2);	EXPECT_DOUBLE_EQ(val1, val2);	the two double values are almost equal

下面的宏，可以进行浮点数范围比较

Fatal assertion	Nonfatal assertion	Verifies
ASSERT_NEAR(val1, val2, abs_error);	EXPECT_NEAR(val1, val2, abs_error);	the difference between val1 and val2 doesn't exceed the given absolute error

测试代码

 运行结果

[ RUN      ] HelloGtest.case_EXPECT_FLOAT_EQ
[       OK ] HelloGtest.case_EXPECT_FLOAT_EQ (0 ms)
[ RUN      ] HelloGtest.case_EXPECT_NEAR
[       OK ] HelloGtest.case_EXPECT_NEAR (0 ms)
 命中[ 4 ]总行数[ 10 ]覆盖率[40.0%] 

EXPECT_DEATH
EXPECT_EXIT

Death Test终止测试

使用场景：检验程序的退出码，退出信号，退出时打印的字符串

终止测试的宏如下

Fatal assertion	Nonfatal assertion	Verifies
ASSERT_DEATH(statement, matcher);	EXPECT_DEATH(statement, matcher);	statement crashes with the given error
ASSERT_DEATH_IF_SUPPORTED(statement, matcher);	EXPECT_DEATH_IF_SUPPORTED(statement, matcher);	if death tests are supported, verifies that statement crashes with the given error; otherwise verifies nothing
ASSERT_DEBUG_DEATH(statement, matcher);	EXPECT_DEBUG_DEATH(statement, matcher);	statement crashes with the given error in debug mode. When not in debug (i.e. NDEBUG is defined), this just executes statement
ASSERT_EXIT(statement, predicate, matcher);	EXPECT_EXIT(statement, predicate, matcher);	statement exits with the given error, and its exit code matches predicate

设置期待程序退出时的exit code

ExitedWithCode(exit_code)

设置程序退出时收到的Signal (只支持在Linux上使用)

KilledBySignal(signal_number)  // Not available on Windows.

字符串检查支持正则表达式

Expression	Meaning
c	matches any literal character c
\\d	matches any decimal digit
\\D	matches any character that's not a decimal digit
\\f	matches \f
\\n	matches \n
\\r	matches \r
\\s	matches any ASCII whitespace, including \n
\\S	matches any character that's not a whitespace
\\t	matches \t
\\v	matches \v
\\w	matches any letter, _, or decimal digit
\\W	matches any character that \\w doesn't match
\\c	matches any literal character c, which must be a punctuation
.	matches any single character except \n
A?	matches 0 or 1 occurrences of A
A*	matches 0 or many occurrences of A
A+	matches 1 or many occurrences of A
^	matches the beginning of a string (not that of each line)
$	matches the end of a string (not that of each line)
xy	matches x followed by y

测试代码

运行结果

[ RUN      ] DeathTest.case_EXPECT_DEATH
[       OK ] DeathTest.case_EXPECT_DEATH (94 ms)
[ RUN      ] DeathTest.NormalExit
case_EXPECT_DEATH.c:21: Failure
Death test: GetValueFloat(3)
    Result: died but not with expected exit code:
            Exited with exit status 123
Actual msg:
[  DEATH   ] 
 命中[ 3 ]总行数[ 10 ]覆盖率[30.0%]