Googlemock暂停期望

Question

我有一个场景，我希望对模拟对象上的函数进行一些调用，然后对于特定的代码路径，我需要确保该函数不被调用，然后，它被调用。有没有办法做到这一点？

EXPECT_CALL(mockObj, 1); 
foo(1);

// Expect this call at the first invocation of foo(2)
EXPECT_CALL(mockObj, 2); 
foo(2);

// These calls should not call my mockObj again, the above expectation is 
// intended for the first invocation of foo(2)
foo(2);
foo(2);

// And now, i expect it to be called
EXPECT_CALL(mockObj, 3); 
foo(3);

我可以检查EXPECT_CALL(mockObj，2)；是否只被调用了预期次数，但我还想确认它只在第一次调用foo(2)时调用，而不是在随后调用foo(2)时调用。你能让我知道在gmock中实现这一点的任何方法吗？

Answer 1

Gmock cookbook建议使用虚拟检查点模拟函数

using ::testing::MockFunction;

TEST(FooTest, InvokesMyMockCorrectly) {
  MyMock mockObj;
  // Class MockFunction<F> has exactly one mock method.  It is named
  // Call() and has type F.
  MockFunction<void(string check_point_name)> check;
  {
    InSequence s;

    EXPECT_CALL(mockObj, 1);
    EXPECT_CALL(check, "1");
    EXPECT_CALL(mockObj, 2);
    EXPECT_CALL(check, "2");
    EXPECT_CALL(check, "3");
    EXPECT_CALL(mockObj, 3);
  }
  
  foo(1);
  check.Call("1");

  foo(2);
  check.Call("2");

  foo(2);
  foo(2);

  check.Call("3");
  foo(3);
}

或者使用Mock::VerifyAndClearExpectations()重置模拟，然后设置新的期望。

否则，像某些答案中建议的那样，交叉调用模拟和EXPECT_CALLs是未定义的行为：

重要说明: gMock要求在调用模拟函数之前设置期望，否则行为是未定义的。特别是，您不能交错EXPECT_CALL()和对模拟函数的调用。

来自gmock for dummies，也请参阅Interleaving EXPECT_CALL()s and calls to the mock functions

Answer 2

我会把它分成几个测试用例：

TEST(Foo, CalledOnFirstInvoation) {
  EXPECT_CALL(mockObj, 1); 
  foo(1);
}

TEST(Foo, CalledAgainWhenUsingDifferenArgument) {
  EXPECT_CALL(mockObj, 2); 
  foo(1);
  foo(2);
}

TEST(Foo, NotCalledWhenUsingSameArgument) {
  EXPECT_CALL(mockObj, 2); 
  foo(1);
  foo(2);
  foo(2);
  foo(2);
}

TEST(Foo, CalledAgainWhenUsingYetAnotherArgument) {
  EXPECT_CALL(mockObj, 3); 
  foo(1);
  foo(2);
  foo(2);
  foo(3);
}

Answer 3

你想得到这样的东西吗？

EXPECT_CALL(mockObj, 1).Times(0);
EXPECT_CALL(mockObj, 2).Times(0); // #2
EXPECT_CALL(mockObj, 3); // #3

{
  EXPECT_CALL(mockObj, 1); // #1
  foo(1); // Matches #1
}

{
  EXPECT_CALL(mockObj, 2); // #4
  // Expect this call at the first invocation of foo(2)
  foo(2); // Matches #4
}

// These calls should not call my mockObj again, the above expectation is 
// intended for the first invocation of foo(2)
foo(2); // Matches #2
foo(2); // Matches #2

// And now, i expect it to be called
foo(3); // Matches #3