单元测试采用“特征”模板参数的对象
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11-12-2019 - |
题
我有一个Visual Studio 2008 C ++ 03项目,我想要单位测试使用公开静态方法的特征模板参数的类(基于策略的设计,策略模式)。我正在使用谷歌测试和谷歌模拟框架。
例如:
/// the class under test
template< typename FooTraits >
class Foo
{
public:
void DoSomething()
{
FooTraits::handle_type h = FooTraits::Open( "Foo" );
/* ... */
FooTraits::Close( h );
};
};
/// a typical traits structure
struct SomeTraits
{
typedef HANDLE handle_type;
static handle_type Open( const char* name ) { /* ... */ };
static void Close( handle_type h ) { /* ... */ };
};
/// mocked traits that I would like to use for testing
struct MockTraits
{
typedef int handle_type;
static MOCK_METHOD1( Open, handle_type( const char* ) );
static MOCK_METHOD1( Close, void( handle_type ) );
};
/// the test function
TEST( FooTest, VerifyDoSomethingWorks )
{
Foo< MockTraits > foo_under_test;
// expect MockTraits::Open is called once
// expect MockTraits::Close is called once with the parameter returned from Open
foo_under_test.DoSomething();
};
.
显然,这不会像 - 是的。Google Mock无法模拟静态方法,我需要在测试中创建模型类的实例,以设置其行为和期望。
因此,单位测试使用Google Test / Google Mock的类别接受模板策略的类是什么?
解决方案
您可以使用非静态方法进行类,创建一个全球实例(或您的特征中的静态),并将您的特征类推迟到它?
所以,澄清由Rob的评论启发的想法:
struct FunnyDoodad
{
FunnyDoodad();
~FunnyDoodad();
MOCK_METHOD1( Open, HANDLE( const char* ) );
MOCK_METHOD1( Close, void( handle_type ) );
};
struct FunnyGlobal {
FunnyGlobal() : pimpl() {}
~FunnyGlobal() { delete pimpl; }
// You'd want some protection here rather than just dereferencing.
// it's the whole point. I'd suggest using whatever unit test assertion
// mechanism your framework uses and make it a fatal check.
handle_type Open(char const* name) { return pimpl->Open(name); }
void Close(handle_type h) { pimpl->Close(h); }
private:
FunnyDoodad * pimpl;
friend struct FunnyDoodad;
void register(FunnyDoodad* p) { pimpl = p; }
void deregister() { pimpl = 0; }
};
FunnyGlobal funnyGlobal;
FunnyDoodad::FunnyDoodad() { funnyGlobal.register(this); }
FunnyDoodad::~FunnyDoodad() { funnyGlobal.deregister(); }
struct TestTraits
{
typedef HANDLE handle_type;
static handle_type Open( const char* name ) { return funnyGlobal.Open(name); };
static void Close( handle_type h ) { funnyGlobal.Close(h); };
};
TEST_CASE(blah)
{
FunnyDoodad testDoodad;
...
}
.
我想象上面可以采用模板,几乎变成了一个模式......也许。
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