unit-testing - GTest:TYPE_TESTING 全局函数时需要夹具?
问题描述
我想使用TYPED_TEST
. 以下代码有效,我只是想知道是否有办法摆脱测试夹具,因为它似乎不需要..
#include <gtest/gtest.h>
#include <base/mathfunctions.h>
template <class T>
class MinTest : public testing::Test {};
// The list of types we want to test.
typedef ::testing::Types<int, float> Implementations;
TYPED_TEST_CASE(MinTest, Implementations);
TYPED_TEST(MinTest, ReturnsMinimumValue)
{
EXPECT_EQ(Base::Min<TypeParam>(-5, 5), -5);
}
解决方案
...因为它似乎不需要
这是必需的。请参阅您的单元测试源的这个独立的简化(它使名称无意义ReturnsMinimumValue
,但这没关系):
gtester.cpp
#include <gtest/gtest.h>
template<typename T>
struct foo {
static T bar() {
return 0;
}
};
template <class T>
class MinTest : public testing::Test {};
typedef ::testing::Types<int, float> Implementations;
TYPED_TEST_CASE(MinTest, Implementations);
TYPED_TEST(MinTest, ReturnsMinimumValue)
{
EXPECT_EQ(foo<TypeParam>::bar(),0);
}
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
编译、链接并运行它:
$ g++ -Wall -Wextra -o gtester gtester.cpp -lgtest -pthread && ./gtester
[==========] Running 2 tests from 2 test cases.
[----------] Global test environment set-up.
[----------] 1 test from MinTest/0, where TypeParam = int
[ RUN ] MinTest/0.ReturnsMinimumValue
[ OK ] MinTest/0.ReturnsMinimumValue (0 ms)
[----------] 1 test from MinTest/0 (0 ms total)
[----------] 1 test from MinTest/1, where TypeParam = float
[ RUN ] MinTest/1.ReturnsMinimumValue
[ OK ] MinTest/1.ReturnsMinimumValue (0 ms)
[----------] 1 test from MinTest/1 (0 ms total)
[----------] Global test environment tear-down
[==========] 2 tests from 2 test cases ran. (0 ms total)
[ PASSED ] 2 tests.
现在让我们预处理源文件,并美化预处理后的输出(因为它不漂亮):
$ g++ -E -P gtester.cpp | clang-format > gtester.ii
查看输出的最后 50 多行:
gtester.ii
...
...
int RUN_ALL_TESTS() __attribute__((warn_unused_result));
inline int RUN_ALL_TESTS() { return ::testing::UnitTest::GetInstance()->Run(); }
template <typename T> struct foo {
static T bar() { return 0; }
};
template <class T> class MinTest : public testing::Test {};
typedef ::testing::Types<int, float> Implementations;
typedef ::testing::internal::TypeList<Implementations>::type
gtest_type_params_MinTest_;
template <typename gtest_TypeParam_>
class MinTest_ReturnsMinimumValue_Test : public MinTest<gtest_TypeParam_> {
private:
typedef MinTest<gtest_TypeParam_> TestFixture;
typedef gtest_TypeParam_ TypeParam;
virtual void TestBody();
};
bool gtest_MinTest_ReturnsMinimumValue_registered_ __attribute__((unused)) =
::testing::internal::TypeParameterizedTest<
MinTest,
::testing::internal::TemplateSel<MinTest_ReturnsMinimumValue_Test>,
gtest_type_params_MinTest_>::Register("",
::testing::internal::CodeLocation(
"gtester.cpp", 17),
"MinTest", "ReturnsMinimumValue",
0);
template <typename gtest_TypeParam_>
void MinTest_ReturnsMinimumValue_Test<gtest_TypeParam_>::TestBody() {
switch (0)
case 0:
default:
if (const ::testing::AssertionResult gtest_ar =
(::testing::internal::EqHelper<(
sizeof(::testing::internal::IsNullLiteralHelper(
foo<TypeParam>::bar())) ==
1)>::Compare("foo<TypeParam>::bar()", "0",
foo<TypeParam>::bar(), 0)))
;
else
::testing::internal::AssertHelper(
::testing::TestPartResult::kNonFatalFailure, "gtester.cpp", 19,
gtest_ar.failure_message()) = ::testing::Message();
}
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
我们的:
TYPED_TEST(MinTest, ReturnsMinimumValue)
{
EXPECT_EQ(foo<TypeParam>::bar(),0);
}
扩展到以下定义:
template <typename gtest_TypeParam_>
class MinTest_ReturnsMinimumValue_Test;
这是从模板夹具派生的:
template <class T> class MinTest;
源自:
testing::Test;
从中MinTest_ReturnsMinimumValue_Test
继承:
virtual void TestBody();
并将其覆盖为:
void MinTest_ReturnsMinimumValue_Test<gtest_TypeParam_>::TestBody() {
switch (0)
case 0:
default:
if (const ::testing::AssertionResult gtest_ar =
(::testing::internal::EqHelper<(
sizeof(::testing::internal::IsNullLiteralHelper(
foo<TypeParam>::bar())) ==
1)>::Compare("foo<TypeParam>::bar()", "0",
foo<TypeParam>::bar(), 0)))
;
else
::testing::internal::AssertHelper(
::testing::TestPartResult::kNonFatalFailure, "gtester.cpp", 19,
gtest_ar.failure_message()) = ::testing::Message();
}
它实现了以下扩展:
EXPECT_EQ(foo<TypeParam>::bar(),0);
不同的测试框架可能会以不同的方式完成类型参数化的测试用例,但这就是 googletest 的做法。
多态类层次结构:
template <typename gtest_TypeParam_>
class MinTest_ReturnsMinimumValue_Test
<-
template <class T> class MinTest
<-
testing::Test
不会生成,因为任何假设被测方法调用是多态的。foo<TypeParam>::bar()
,当然不是。生成多态类层次结构是因为这是 googletest 的基本设计。