c++ - 在 Gmock 的 EXPECT_CALL 之前使用 ON_CALL 时的奇怪行为

Question

在 ON_CALL 语句后面加上 EXPECT_CALL 语句时，有没有人见过 gmock 中的奇怪行为？对我来说，以下代码中的 EXPECT_CALL 语句不起作用(它实际上并不强制执行 Times 部分):

ON_CALL(myMockObject, myMockMethod()).WillByDefault(Return("hello mock")));
EXPECT_CALL(myMockObject, myMockMethod()).Times(99999);
myMockObject.myMockMethod();

我尝试过的其他解决方案:

重写父类(super class)中的 myMockMethod 并让它仅返回字符串文字。问题是我无法确定它后来被调用了多少次。

跳过 ON_CALL 部分，转而采用如下方式:

EXPECT_CALL(myMockObject, myMockMethod())
    .Times(1)
    .WillRepeatedly(Return("hello mock"));

这会导致编译错误。

还值得注意的是，我在本示例中使用的字符串文字实际上是自定义的，gmock 无法提供默认值(例如 bool)。

Answer 1

您的原始代码中有一些其他错误，您的问题中没有提到这些错误。如果您构建一个最小的独立示例，问题中提供的代码的行为将符合您的预期。

例如以下代码:

#include <string>
#include "gmock/gmock.h"

using ::testing::Return;

struct MyClass {
  virtual ~MyClass() {}
  virtual std::string myMockMethod() = 0;
};

struct MyMockClass : MyClass {
  MOCK_METHOD0(myMockMethod, std::string());
};

TEST(MyClass, Fails) {
  MyMockClass myMockObject;
  ON_CALL(myMockObject, myMockMethod()).WillByDefault(Return("hello mock"));
  EXPECT_CALL(myMockObject, myMockMethod()).Times(99999);
  myMockObject.myMockMethod();
}

TEST(MyClass, Passes) {
  MyMockClass myMockObject;
  EXPECT_CALL(myMockObject, myMockMethod()).Times(1).WillRepeatedly(Return("hello mock"));
  myMockObject.myMockMethod();
}

int main(int argc, char **argv) {
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}

产生以下(预期)输出:

[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[==========] 2 tests from MyClass
[ RUN      ] MyClass.Fails
..\src\main.cc(18): error: Actual function call count doesn't match EXPECT_CALL(myMockObject, myMockMethod())...
         Expected: to be called 99999 times
           Actual: called once - unsatisfied and active
[  FAILED  ] MyClass.Fails (0 ms)
[ RUN      ] MyClass.Passes
[       OK ] MyClass.Passes (0 ms)
[----------] 2 tests from MyClass (2 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (2 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] MyClass.Fails

 1 FAILED TEST

如果您希望模拟对象保存在测试装置中，您可以这样做:

class MyClassTest : public testing::Test {
 protected:
  MyMockClass myMockObject_;
};

TEST_F(MyClassTest, Fails) {
  ON_CALL(myMockObject_, myMockMethod()).WillByDefault(Return("hello mock"));
  EXPECT_CALL(myMockObject_, myMockMethod()).Times(99999);
  myMockObject_.myMockMethod();
}