是什麼saveArg和saveArgPointee的gmock區別？

Question

我在gmock學習。現在，我試着去嘲笑爲「任務」之類的，就像這樣：

class MockTask : public Task 
{ 
public: 
    MOCK_METHOD3(Execute, bool(std::set<std::string> &setDeviceIDs, int timeout, PACKET_DATA *Data)); 
}; 

我想保存結構PDATA當task.excute被調用，這樣我可以驗證pdata->成員。這是我的代碼：

PAKET_DATA data; 
EXPECT_CALL(task, Execute(testing::_, testing::_, testing::_)) 
    .WillOnce(testing::saveArg<2>(&data)); 
ASSERT_EQ(data->resultcode, 0); 

這是正確的嗎？ saveArg和saveArgPointee有什麼區別？

Answer 1

正如你可以在gmock doc讀：

SaveArg（指針）保存第N（從0開始）參數來*指針。

SaveArgPointee（指針）保存的值所指向的第N（從0開始）參數來*指針。

對於你的情況，你應該使用SaveArgPointee - 選擇要保存所指的數據（PACKET_DATA *Data） - 在本例中沒有指針本身...

看：

struct SomeData { int a; }; 
class ISomeClass 
{ 
public: 
    virtual ~ISomeClass() = default; 
    virtual void foo(SomeData*) = 0; 
}; 

void someFunction(ISomeClass& a) 
{ 
    SomeData b{1}; 
    a.foo(&b); 
} 

class SomeMock : public ISomeClass 
{ 
public: 
    MOCK_METHOD1(foo, void(SomeData*)); 
}; 

要測試someFunction您需要檢查正在傳遞到foo指針對象：

TEST(TestSomeFoo, shallPassOne) 
{ 
    SomeData actualData{}; 
    SomeMock aMock; 
    EXPECT_CALL(aMock, foo(_)).WillOnce(::testing::SaveArgPointee<0>(&actualData)); 
    someFunction(aMock); 
    ASSERT_EQ(1, actualData.a); 
} 

如果使用SaveArg - 你只是存儲指向不再存在局部變量：

TEST(TestSomeFoo, shallPassOne_DanglingPointer) 
{ 
    SomeData* actualData; 
    SomeMock aMock; 
    EXPECT_CALL(aMock, foo(_)).WillOnce(::testing::SaveArg<0>(&actualData)); 
    someFunction(aMock); 
    ASSERT_EQ(1, actualData->a); 
} 

Answer 2

If I replace the test 
TEST(TestSomeFoo, shallPassOne) 
{ 
    SomeData actualData{}; 
    SomeMock aMock; 
    EXPECT_CALL(aMock, foo(_)).WillOnce(::testing::SaveArgPointee<0>(&actualData)); 
    someFunction(aMock); 
    ASSERT_EQ(1, actualData.a); 
} 

as 

TEST(TestSomeFoo, shallPassOne) 
{ 
    SomeData actualData{1}; 
    SomeMock aMock; 
    EXPECT_CALL(aMock, foo(actualData)).Times(1); 
    someFunction(aMock); 
} 

這會不會是相同的或有什麼差別？