1.7 sample7--接口测试
值参数不限定类型，也可以是类的引用，这就可以实现对类接口的测试，一个基类可以有多个继承类，那么可以测试不同的子类功能，但是只需要写一个测试用例，然后使用参数列表实现对每个子类的测试。
使用值参数测试法去测试多个实现了相同接口（类）的共同属性（又叫做接口测试）
using ::testing::TestWithParam;
using ::testing::Values;
typedef PrimeTable* CreatePrimeTableFunc();
PrimeTable* CreateOnTheFlyPrimeTable() {
return new OnTheFlyPrimeTable();
}
template <size_t max_precalculated>
PrimeTable* CreatePreCalculatedPrimeTable() {
return new PreCalculatedPrimeTable(max_precalculated);
}
// Inside the test body, fixture constructor, SetUp(), and TearDown() you
// can refer to the test parameter by GetParam(). In this case, the test
// parameter is a factory function which we call in fixture's SetUp() to
// create and store an instance of PrimeTable.
class PrimeTableTestSmpl7 : public TestWithParam<CreatePrimeTableFunc*> {
public:
~PrimeTableTestSmpl7() override { delete table_; }
void SetUp() override { table_ = (*GetParam())(); }
void TearDown() override {
delete table_;
table_ = nullptr;
}
protected:
PrimeTable* table_;
};
TEST_P(PrimeTableTestSmpl7, ReturnsFalseForNonPrimes) {
EXPECT_FALSE(table_->IsPrime(-5));
EXPECT_FALSE(table_->IsPrime(0));
EXPECT_FALSE(table_->IsPrime(1));
EXPECT_FALSE(table_->IsPrime(4));
EXPECT_FALSE(table_->IsPrime(6));
EXPECT_FALSE(table_->IsPrime(100));
}
TEST_P(PrimeTableTestSmpl7, ReturnsTrueForPrimes) {
EXPECT_TRUE(table_->IsPrime(2));
EXPECT_TRUE(table_->IsPrime(3));
EXPECT_TRUE(table_->IsPrime(5));
EXPECT_TRUE(table_->IsPrime(7));
EXPECT_TRUE(table_->IsPrime(11));
EXPECT_TRUE(table_->IsPrime(131));
} TEST_P(PrimeTableTestSmpl7, CanGetNextPrime) {
EXPECT_EQ(2, table_->GetNextPrime(1));
EXPECT_EQ(3, table_->GetNextPrime(2));
EXPECT_EQ(5, table_->GetNextPrime(3));
EXPECT_EQ(7, table_->GetNextPrime(5));
EXPECT_EQ(11, table_->GetNextPrime(7));
EXPECT_EQ(131, table_->GetNextPrime(128));
}
// In order to run value-parameterized tests, you need to instantiate them,
// or bind them to a list of values which will be used as test parameters.
// You can instantiate them in a different translation module, or even
// instantiate them several times.
//
// Here, we instantiate our tests with a list of two PrimeTable object
// factory functions:
#define INSTANTIATE_TEST_SUITE_P INSTANTIATE_TEST_CASE_P
INSTANTIATE_TEST_SUITE_P(OnTheFlyAndPreCalculated, PrimeTableTestSmpl7,
Values(&CreateOnTheFlyPrimeTable,
&CreatePreCalculatedPrimeTable<1000>));
1.8sample8--值参数测试
有些时候，我们需要对代码实现的功能使用不同的参数进行测试，比如使用大量随机值来检验算法实现的正确性，或者比较同一个接口的不同实现之间的差别。gtest把“集中输入测试参数”的需求抽象出来提供支持，称为值参数化测试（Value Parameterized Test）。
| 参数值序列生成函数 | 含义 |
|---|---|
Bool() |
生成序列 {false, true}
|
Range(begin, end[, step]) |
生成序列 {begin, begin+step, begin+2*step, ...} (不含 end)， step默认为1 |
Values(v1, v2, ..., vN)
|
生成序列 {v1, v2, ..., vN}
|
ValuesIn(container), ValuesIn(iter1, iter2)
|
枚举STL container，或枚举迭代器范围 [iter1, iter2)
|
Combine(g1, g2, ..., gN)
|
生成 g1, g2, ..., gN的笛卡尔积，其中g1, g2, ..., gN均为参数值序列生成函数（要求C++0x的<tr1/tuple>） |
代码实现
class HybridPrimeTable : public PrimeTable {
public:
HybridPrimeTable(bool force_on_the_fly, int max_precalculated)
: on_the_fly_impl_(new OnTheFlyPrimeTable),
precalc_impl_(force_on_the_fly
? nullptr
: new PreCalculatedPrimeTable(max_precalculated)),
max_precalculated_(max_precalculated) {}
~HybridPrimeTable() override {
delete on_the_fly_impl_;
delete precalc_impl_;
}
bool IsPrime(int n) const override {
if (precalc_impl_ != nullptr && n < max_precalculated_)
return precalc_impl_->IsPrime(n);
else
return on_the_fly_impl_->IsPrime(n);
}
int GetNextPrime(int p) const override {
int next_prime = -1;
if (precalc_impl_ != nullptr && p < max_precalculated_)
next_prime = precalc_impl_->GetNextPrime(p);
return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p);
}
private:
OnTheFlyPrimeTable* on_the_fly_impl_;
PreCalculatedPrimeTable* precalc_impl_;
int max_precalculated_;
};
using ::testing::TestWithParam;
using ::testing::Bool;
using ::testing::Values;
using ::testing::Combine;
// To test all code paths for HybridPrimeTable we must test it with numbers
// both within and outside PreCalculatedPrimeTable's capacity and also with
// PreCalculatedPrimeTable disabled. We do this by defining fixture which will
// accept different combinations of parameters for instantiating a
// HybridPrimeTable instance.
class PrimeTableTest : public TestWithParam< ::std::tuple<bool, int> > {
protected:
void SetUp() override {
bool force_on_the_fly;
int max_precalculated;
std::tie(force_on_the_fly, max_precalculated) = GetParam();
table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated);
}
void TearDown() override {
delete table_;
table_ = nullptr;
}
HybridPrimeTable* table_;
};
PrimeTableTest类继承于TestWithParam，是测试固件类。接收参数tuple<bool,int>，如果bool为true时，使用OnTheFlyPrimeTable类的接口，当bool变量为false时，使用PreCalculatedPrimeTable接口测试。
测试编写：
TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) {
EXPECT_FALSE(table_->IsPrime(-5));
EXPECT_FALSE(table_->IsPrime(0));
EXPECT_FALSE(table_->IsPrime(1));
EXPECT_FALSE(table_->IsPrime(4));
EXPECT_FALSE(table_->IsPrime(6));
EXPECT_FALSE(table_->IsPrime(100));
}
TEST_P(PrimeTableTest, ReturnsTrueForPrimes) {
EXPECT_TRUE(table_->IsPrime(2));
EXPECT_TRUE(table_->IsPrime(3));
EXPECT_TRUE(table_->IsPrime(5));
EXPECT_TRUE(table_->IsPrime(7));
EXPECT_TRUE(table_->IsPrime(11));
EXPECT_TRUE(table_->IsPrime(131));
}
TEST_P(PrimeTableTest, CanGetNextPrime) {
EXPECT_EQ(2, table_->GetNextPrime(0));
EXPECT_EQ(3, table_->GetNextPrime(2));
EXPECT_EQ(5, table_->GetNextPrime(3));
EXPECT_EQ(7, table_->GetNextPrime(5));
EXPECT_EQ(11, table_->GetNextPrime(7));
EXPECT_EQ(131, table_->GetNextPrime(128));
}
#define INSTANTIATE_TEST_SUITE_P INSTANTIATE_TEST_CASE_P
INSTANTIATE_TEST_SUITE_P(MeaningfulTestParameters, PrimeTableTest,
Combine(Bool(), Values(1, 10)));
共计3个测试case，测试名为MeaningfulTestParameters，输入的参数是一个comine类，生成正交参数集合：
Combine(Bool(), Values(1, 10)));
// Combine() allows the user to combine two or more sequences to produce
// values of a Cartesian product of those sequences' elements.
/*
|--Bool--|--------- Value---------|
| | 1 | 10 |
| true | (true,1) | (true,10) |
| false | (false,1) | (false,10) |
*/
本例有3个测试，参数正交后是4组参数，每组参数运行一次测试，所以输出12个测试结果。运行截图如下。
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Google单元测试框架gtest之官方sample笔记1--简单用例