在 google mock 中执行调用函数的顺序

Question

我正在学习如何使用 google mock。我观察到以下代码作为示例来指定函数调用的顺序。这里我们使用 InSequence 对象但没有在代码中的任何地方使用。请求指导我 TEST_F 在内部使用 C++ 技术的想法来使用这个对象并强制执行 oder

TEST_F(APlaceDescriptionService, MakesHttpRequestToObtainAddress) {
InSequence forceExpectationOrder;
HttpStub httpStub;
string urlStart{
"http://open.mapquestapi.com/nominatim/v1/reverse?format=json&"};
auto expectedURL = urlStart +
"lat=" + APlaceDescriptionService::ValidLatitude + "&" +
"lon=" + APlaceDescriptionService::ValidLongitude;
EXPECT_CALL(httpStub, initialize());
EXPECT_CALL(httpStub, get(expectedURL));
PlaceDescriptionService service{&httpStub};
service.summaryDescription(ValidLatitude, ValidLongitude);
}

Answer 1

想法很简单：如果 HttpStub::get 在 HttpStub::initialize 之前被调用，那么测试 APlaceDescriptionService.MakesHttpRequestToObtainAddress 将失败。换句话说，测试确保 HttpStub::get 在 httpStub 初始化之前不会被调用。

如果您的问题是它是如何工作的：

InSequence forceExpectationOrder 在创建时将 new Sequence 对象设置为全局对象 g_gmock_implicit_sequence，该对象按创建顺序使用期望链。

// Points to the implicit sequence introduced by a living InSequence
// object (if any) in the current thread or NULL.
GTEST_API_ ThreadLocal<Sequence*> g_gmock_implicit_sequence;

// Creates the implicit sequence if there isn't one.
InSequence::InSequence() {
  if (internal::g_gmock_implicit_sequence.get() == nullptr) {
    internal::g_gmock_implicit_sequence.set(new Sequence);
    sequence_created_ = true;
  }
  // ...
}

// Deletes the implicit sequence if it was created by the constructor
// of this object.
InSequence::~InSequence() {
  if (sequence_created_) {
    delete internal::g_gmock_implicit_sequence.get();
    internal::g_gmock_implicit_sequence.set(nullptr);
  }
}

// Adds and returns an expectation spec for this mock function.
TypedExpectation<F>& AddNewExpectation(const char* file, int line,
                                       const std::string& source_text,
                                       const ArgumentMatcherTuple& m) {
  // ...

  // Adds this expectation into the implicit sequence if there is one.
  Sequence* const implicit_sequence = g_gmock_implicit_sequence.get();
  if (implicit_sequence != nullptr) {
    implicit_sequence->AddExpectation(Expectation(untyped_expectation));
  }

  return *expectation;
}

在 google mock 中执行调用函数的顺序

enforcing order of calling function in google mock

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