-* 1.8.x Release - the 1.8.x will be the last release that works with pre-C++11 compilers. The 1.8.x will not accept any requests for any new features and any bugfix requests will only be accepted if proven "critical"
-* Post 1.8.x - work to improve/cleanup/pay technical debt. When this work is completed there will be a 1.9.x tagged release
-* Post 1.9.x googletest will follow [Abseil Live at Head philosophy](https://abseil.io/about/philosophy)
+### Future Plans
+#### 1.8.x Release:
-Welcome to **Google Test**, Google's C++ test framework!
+[the 1.8.x](https://github.com/google/googletest/releases/tag/release-1.8.1) is
+the last release that works with pre-C++11 compilers. The 1.8.x will not accept
+any requests for any new features and any bugfix requests will only be accepted
+if proven "critical"
-This repository is a merger of the formerly separate GoogleTest and
-GoogleMock projects. These were so closely related that it makes sense to
-maintain and release them together.
+#### Post 1.8.x:
-Please see the project page above for more information as well as the
-mailing list for questions, discussions, and development. There is
-also an IRC channel on [OFTC](https://webchat.oftc.net/) (irc.oftc.net) #gtest available. Please
-join us!
+On-going work to improve/cleanup/pay technical debt. When this work is completed
+there will be a 1.9.x tagged release
-Getting started information for **Google Test** is available in the
+#### Post 1.9.x
+
+Post 1.9.x googletest will follow
+[Abseil Live at Head philosophy](https://abseil.io/about/philosophy)
+
+## Welcome to **Google Test**, Google's C++ test framework!
+
+This repository is a merger of the formerly separate GoogleTest and GoogleMock
+projects. These were so closely related that it makes sense to maintain and
+release them together.
+
+Please subscribe to the mailing list at googletestframework@googlegroups.com for
+questions, discussions, and development.
+
+### Getting started:
+
+The information for **Google Test** is available in the
[Google Test Primer](googletest/docs/primer.md) documentation.
**Google Mock** is an extension to Google Test for writing and using C++ mock
-classes. See the separate [Google Mock documentation](googlemock/README.md).
+classes. See the separate [Google Mock documentation](googlemock/README.md).
-More detailed documentation for googletest (including build instructions) are
-in its interior [googletest/README.md](googletest/README.md) file.
+More detailed documentation for googletest is in its interior
+ dependency-free deep learning framework in C++11.
-## Related Open Source Projects ##
+## Related Open Source Projects
-[GTest Runner](https://github.com/nholthaus/gtest-runner) is a Qt5 based automated test-runner and Graphical User Interface with powerful features for Windows and Linux platforms.
+[GTest Runner](https://github.com/nholthaus/gtest-runner) is a Qt5 based
+automated test-runner and Graphical User Interface with powerful features for
+Windows and Linux platforms.
-[Google Test UI](https://github.com/ospector/gtest-gbar) is test runner that runs
-your test binary, allows you to track its progress via a progress bar, and
+[Google Test UI](https://github.com/ospector/gtest-gbar) is test runner that
+runs your test binary, allows you to track its progress via a progress bar, and
displays a list of test failures. Clicking on one shows failure text. Google
Test UI is written in C#.
[GTest TAP Listener](https://github.com/kinow/gtest-tap-listener) is an event
listener for Google Test that implements the
[TAP protocol](https://en.wikipedia.org/wiki/Test_Anything_Protocol) for test
result output. If your test runner understands TAP, you may find it useful.
[gtest-parallel](https://github.com/google/gtest-parallel) is a test runner that
runs tests from your binary in parallel to provide significant speed-up.
-[GoogleTest Adapter](https://marketplace.visualstudio.com/items?itemName=DavidSchuldenfrei.gtest-adapter) is a VS Code extension allowing to view Google Tests in a tree view, and run/debug your tests.
-Your code should talk to `FileInterface` to open a file. Now it's
-easy to mock out the function.
-
-This may seem much hassle, but in practice you often have multiple
-related functions that you can put in the same interface, so the
-per-function syntactic overhead will be much lower.
-
-If you are concerned about the performance overhead incurred by
-virtual functions, and profiling confirms your concern, you can
-combine this with the recipe for [mocking non-virtual methods](#mocking-nonvirtual-methods).
-
-## The Nice, the Strict, and the Naggy ##
-
-If a mock method has no `EXPECT_CALL` spec but is called, Google Mock
-will print a warning about the "uninteresting call". The rationale is:
-
- * New methods may be added to an interface after a test is written. We shouldn't fail a test just because a method it doesn't know about is called.
- * However, this may also mean there's a bug in the test, so Google Mock shouldn't be silent either. If the user believes these calls are harmless, they can add an `EXPECT_CALL()` to suppress the warning.
-
-However, sometimes you may want to suppress all "uninteresting call"
-warnings, while sometimes you may want the opposite, i.e. to treat all
-of them as errors. Google Mock lets you make the decision on a
-per-mock-object basis.
-
-Suppose your test uses a mock class `MockFoo`:
-
-```
-TEST(...) {
- MockFoo mock_foo;
- EXPECT_CALL(mock_foo, DoThis());
- ... code that uses mock_foo ...
-}
-```
-
-If a method of `mock_foo` other than `DoThis()` is called, it will be
-reported by Google Mock as a warning. However, if you rewrite your
-test to use `NiceMock<MockFoo>` instead, the warning will be gone,
-resulting in a cleaner test output:
-
-```
-using ::testing::NiceMock;
-
-TEST(...) {
- NiceMock<MockFoo> mock_foo;
- EXPECT_CALL(mock_foo, DoThis());
- ... code that uses mock_foo ...
-}
-```
-
-`NiceMock<MockFoo>` is a subclass of `MockFoo`, so it can be used
-wherever `MockFoo` is accepted.
-
-It also works if `MockFoo`'s constructor takes some arguments, as
-The usage of `StrictMock` is similar, except that it makes all
-uninteresting calls failures:
-
-```
-using ::testing::StrictMock;
-
-TEST(...) {
- StrictMock<MockFoo> mock_foo;
- EXPECT_CALL(mock_foo, DoThis());
- ... code that uses mock_foo ...
-
- // The test will fail if a method of mock_foo other than DoThis()
- // is called.
-}
-```
-
-There are some caveats though (I don't like them just as much as the
-next guy, but sadly they are side effects of C++'s limitations):
-
- 1. `NiceMock<MockFoo>` and `StrictMock<MockFoo>` only work for mock methods defined using the `MOCK_METHOD*` family of macros **directly** in the `MockFoo` class. If a mock method is defined in a **base class** of `MockFoo`, the "nice" or "strict" modifier may not affect it, depending on the compiler. In particular, nesting `NiceMock` and `StrictMock` (e.g. `NiceMock<StrictMock<MockFoo> >`) is **not** supported.
- 1. The constructors of the base mock (`MockFoo`) cannot have arguments passed by non-const reference, which happens to be banned by the [Google C++ style guide](https://google.github.io/styleguide/cppguide.html).
- 1. During the constructor or destructor of `MockFoo`, the mock object is _not_ nice or strict. This may cause surprises if the constructor or destructor calls a mock method on `this` object. (This behavior, however, is consistent with C++'s general rule: if a constructor or destructor calls a virtual method of `this` object, that method is treated as non-virtual. In other words, to the base class's constructor or destructor, `this` object behaves like an instance of the base class, not the derived class. This rule is required for safety. Otherwise a base constructor may use members of a derived class before they are initialized, or a base destructor may use members of a derived class after they have been destroyed.)
-
-Finally, you should be **very cautious** about when to use naggy or strict mocks, as they tend to make tests more brittle and harder to maintain. When you refactor your code without changing its externally visible behavior, ideally you should't need to update any tests. If your code interacts with a naggy mock, however, you may start to get spammed with warnings as the result of your change. Worse, if your code interacts with a strict mock, your tests may start to fail and you'll be forced to fix them. Our general recommendation is to use nice mocks (not yet the default) most of the time, use naggy mocks (the current default) when developing or debugging tests, and use strict mocks only as the last resort.
-
-## Simplifying the Interface without Breaking Existing Code ##
-
-Sometimes a method has a long list of arguments that is mostly
-By defining a new mock method with a trimmed argument list, we make
-the mock class much more user-friendly.
-
-## Alternative to Mocking Concrete Classes ##
-
-Often you may find yourself using classes that don't implement
-interfaces. In order to test your code that uses such a class (let's
-call it `Concrete`), you may be tempted to make the methods of
-`Concrete` virtual and then mock it.
-
-Try not to do that.
-
-Making a non-virtual function virtual is a big decision. It creates an
-extension point where subclasses can tweak your class' behavior. This
-weakens your control on the class because now it's harder to maintain
-the class' invariants. You should make a function virtual only when
-there is a valid reason for a subclass to override it.
-
-Mocking concrete classes directly is problematic as it creates a tight
-coupling between the class and the tests - any small change in the
-class may invalidate your tests and make test maintenance a pain.
-
-To avoid such problems, many programmers have been practicing "coding
-to interfaces": instead of talking to the `Concrete` class, your code
-would define an interface and talk to it. Then you implement that
-interface as an adaptor on top of `Concrete`. In tests, you can easily
-mock that interface to observe how your code is doing.
-
-This technique incurs some overhead:
-
- * You pay the cost of virtual function calls (usually not a problem).
- * There is more abstraction for the programmers to learn.
-
-However, it can also bring significant benefits in addition to better
-testability:
-
- * `Concrete`'s API may not fit your problem domain very well, as you may not be the only client it tries to serve. By designing your own interface, you have a chance to tailor it to your need - you may add higher-level functionalities, rename stuff, etc instead of just trimming the class. This allows you to write your code (user of the interface) in a more natural way, which means it will be more readable, more maintainable, and you'll be more productive.
- * If `Concrete`'s implementation ever has to change, you don't have to rewrite everywhere it is used. Instead, you can absorb the change in your implementation of the interface, and your other code and tests will be insulated from this change.
-
-Some people worry that if everyone is practicing this technique, they
-will end up writing lots of redundant code. This concern is totally
-understandable. However, there are two reasons why it may not be the
-case:
-
- * Different projects may need to use `Concrete` in different ways, so the best interfaces for them will be different. Therefore, each of them will have its own domain-specific interface on top of `Concrete`, and they will not be the same code.
- * If enough projects want to use the same interface, they can always share it, just like they have been sharing `Concrete`. You can check in the interface and the adaptor somewhere near `Concrete` (perhaps in a `contrib` sub-directory) and let many projects use it.
-
-You need to weigh the pros and cons carefully for your particular
-problem, but I'd like to assure you that the Java community has been
-practicing this for a long time and it's a proven effective technique
-applicable in a wide variety of situations. :-)
-
-## Delegating Calls to a Fake ##
-
-Some times you have a non-trivial fake implementation of an
-interface. For example:
-
-```
-class Foo {
- public:
- virtual ~Foo() {}
- virtual char DoThis(int n) = 0;
- virtual void DoThat(const char* s, int* p) = 0;
-};
-
-class FakeFoo : public Foo {
- public:
- virtual char DoThis(int n) {
- return (n > 0) ? '+' :
- (n < 0) ? '-' : '0';
- }
-
- virtual void DoThat(const char* s, int* p) {
- *p = strlen(s);
- }
-};
-```
-
-Now you want to mock this interface such that you can set expectations
-on it. However, you also want to use `FakeFoo` for the default
-behavior, as duplicating it in the mock object is, well, a lot of
-work.
-
-When you define the mock class using Google Mock, you can have it
-delegate its default action to a fake class you already have, using
-this pattern:
-
-```
-using ::testing::_;
-using ::testing::Invoke;
-
-class MockFoo : public Foo {
- public:
- // Normal mock method definitions using Google Mock.
- FakeFoo fake_; // Keeps an instance of the fake in the mock.
-};
-```
-
-With that, you can use `MockFoo` in your tests as usual. Just remember
-that if you don't explicitly set an action in an `ON_CALL()` or
-`EXPECT_CALL()`, the fake will be called upon to do it:
-
-```
-using ::testing::_;
-
-TEST(AbcTest, Xyz) {
- MockFoo foo;
- foo.DelegateToFake(); // Enables the fake for delegation.
-
- // Put your ON_CALL(foo, ...)s here, if any.
-
- // No action specified, meaning to use the default action.
- EXPECT_CALL(foo, DoThis(5));
- EXPECT_CALL(foo, DoThat(_, _));
-
- int n = 0;
- EXPECT_EQ('+', foo.DoThis(5)); // FakeFoo::DoThis() is invoked.
- foo.DoThat("Hi", &n); // FakeFoo::DoThat() is invoked.
- EXPECT_EQ(2, n);
-}
-```
-
-**Some tips:**
-
- * If you want, you can still override the default action by providing your own `ON_CALL()` or using `.WillOnce()` / `.WillRepeatedly()` in `EXPECT_CALL()`.
- * In `DelegateToFake()`, you only need to delegate the methods whose fake implementation you intend to use.
- * The general technique discussed here works for overloaded methods, but you'll need to tell the compiler which version you mean. To disambiguate a mock function (the one you specify inside the parentheses of `ON_CALL()`), see the "Selecting Between Overloaded Functions" section on this page; to disambiguate a fake function (the one you place inside `Invoke()`), use a `static_cast` to specify the function's type. For instance, if class `Foo` has methods `char DoThis(int n)` and `bool DoThis(double x) const`, and you want to invoke the latter, you need to write `Invoke(&fake_, static_cast<bool (FakeFoo::*)(double) const>(&FakeFoo::DoThis))` instead of `Invoke(&fake_, &FakeFoo::DoThis)` (The strange-looking thing inside the angled brackets of `static_cast` is the type of a function pointer to the second `DoThis()` method.).
- * Having to mix a mock and a fake is often a sign of something gone wrong. Perhaps you haven't got used to the interaction-based way of testing yet. Or perhaps your interface is taking on too many roles and should be split up. Therefore, **don't abuse this**. We would only recommend to do it as an intermediate step when you are refactoring your code.
-
-Regarding the tip on mixing a mock and a fake, here's an example on
-why it may be a bad sign: Suppose you have a class `System` for
-low-level system operations. In particular, it does file and I/O
-operations. And suppose you want to test how your code uses `System`
-to do I/O, and you just want the file operations to work normally. If
-you mock out the entire `System` class, you'll have to provide a fake
-implementation for the file operation part, which suggests that
-`System` is taking on too many roles.
-
-Instead, you can define a `FileOps` interface and an `IOOps` interface
-and split `System`'s functionalities into the two. Then you can mock
-`IOOps` without mocking `FileOps`.
-
-## Delegating Calls to a Real Object ##
-
-When using testing doubles (mocks, fakes, stubs, and etc), sometimes
-their behaviors will differ from those of the real objects. This
-difference could be either intentional (as in simulating an error such
-that you can test the error handling code) or unintentional. If your
-mocks have different behaviors than the real objects by mistake, you
-could end up with code that passes the tests but fails in production.
-
-You can use the _delegating-to-real_ technique to ensure that your
-mock has the same behavior as the real object while retaining the
-ability to validate calls. This technique is very similar to the
-delegating-to-fake technique, the difference being that we use a real
-object instead of a fake. Here's an example:
-
-```
-using ::testing::_;
-using ::testing::AtLeast;
-using ::testing::Invoke;
-
-class MockFoo : public Foo {
- public:
- MockFoo() {
- // By default, all calls are delegated to the real object.
- ON_CALL(*this, DoThis())
- .WillByDefault(Invoke(&real_, &Foo::DoThis));
- ON_CALL(*this, DoThat(_))
- .WillByDefault(Invoke(&real_, &Foo::DoThat));
- ...
- }
- MOCK_METHOD0(DoThis, ...);
- MOCK_METHOD1(DoThat, ...);
- ...
- private:
- Foo real_;
-};
-...
-
- MockFoo mock;
-
- EXPECT_CALL(mock, DoThis())
- .Times(3);
- EXPECT_CALL(mock, DoThat("Hi"))
- .Times(AtLeast(1));
- ... use mock in test ...
-```
-
-With this, Google Mock will verify that your code made the right calls
-(with the right arguments, in the right order, called the right number
-of times, etc), and a real object will answer the calls (so the
-behavior will be the same as in production). This gives you the best
-of both worlds.
-
-## Delegating Calls to a Parent Class ##
-
-Ideally, you should code to interfaces, whose methods are all pure
-virtual. In reality, sometimes you do need to mock a virtual method
-that is not pure (i.e, it already has an implementation). For example:
-
-```
-class Foo {
- public:
- virtual ~Foo();
-
- virtual void Pure(int n) = 0;
- virtual int Concrete(const char* str) { ... }
-};
-
-class MockFoo : public Foo {
- public:
- // Mocking a pure method.
- MOCK_METHOD1(Pure, void(int n));
- // Mocking a concrete method. Foo::Concrete() is shadowed.
- MOCK_METHOD1(Concrete, int(const char* str));
-};
-```
-
-Sometimes you may want to call `Foo::Concrete()` instead of
-`MockFoo::Concrete()`. Perhaps you want to do it as part of a stub
-action, or perhaps your test doesn't need to mock `Concrete()` at all
-(but it would be oh-so painful to have to define a new mock class
-whenever you don't need to mock one of its methods).
-
-The trick is to leave a back door in your mock class for accessing the
-real methods in the base class:
-
-```
-class MockFoo : public Foo {
- public:
- // Mocking a pure method.
- MOCK_METHOD1(Pure, void(int n));
- // Mocking a concrete method. Foo::Concrete() is shadowed.
- MOCK_METHOD1(Concrete, int(const char* str));
-
- // Use this to call Concrete() defined in Foo.
- int FooConcrete(const char* str) { return Foo::Concrete(str); }
-};
-```
-
-Now, you can call `Foo::Concrete()` inside an action by:
-
-```
-using ::testing::_;
-using ::testing::Invoke;
-...
- EXPECT_CALL(foo, Concrete(_))
- .WillOnce(Invoke(&foo, &MockFoo::FooConcrete));
-```
-
-or tell the mock object that you don't want to mock `Concrete()`:
-(Why don't we just write `Invoke(&foo, &Foo::Concrete)`? If you do
-that, `MockFoo::Concrete()` will be called (and cause an infinite
-recursion) since `Foo::Concrete()` is virtual. That's just how C++
-works.)
-
-# Using Matchers #
-
-## Matching Argument Values Exactly ##
-
-You can specify exactly which arguments a mock method is expecting:
-
-```
-using ::testing::Return;
-...
- EXPECT_CALL(foo, DoThis(5))
- .WillOnce(Return('a'));
- EXPECT_CALL(foo, DoThat("Hello", bar));
-```
-
-## Using Simple Matchers ##
-
-You can use matchers to match arguments that have a certain property:
-
-```
-using ::testing::Ge;
-using ::testing::NotNull;
-using ::testing::Return;
-...
- EXPECT_CALL(foo, DoThis(Ge(5))) // The argument must be >= 5.
- .WillOnce(Return('a'));
- EXPECT_CALL(foo, DoThat("Hello", NotNull()));
- // The second argument must not be NULL.
-```
-
-A frequently used matcher is `_`, which matches anything:
-
-```
-using ::testing::_;
-using ::testing::NotNull;
-...
- EXPECT_CALL(foo, DoThat(_, NotNull()));
-```
-
-## Combining Matchers ##
-
-You can build complex matchers from existing ones using `AllOf()`,
-`AnyOf()`, and `Not()`:
-
-```
-using ::testing::AllOf;
-using ::testing::Gt;
-using ::testing::HasSubstr;
-using ::testing::Ne;
-using ::testing::Not;
-...
- // The argument must be > 5 and != 10.
- EXPECT_CALL(foo, DoThis(AllOf(Gt(5),
- Ne(10))));
-
- // The first argument must not contain sub-string "blah".
- EXPECT_CALL(foo, DoThat(Not(HasSubstr("blah")),
- NULL));
-```
-
-## Casting Matchers ##
-
-Google Mock matchers are statically typed, meaning that the compiler
-can catch your mistake if you use a matcher of the wrong type (for
-example, if you use `Eq(5)` to match a `string` argument). Good for
-you!
-
-Sometimes, however, you know what you're doing and want the compiler
-to give you some slack. One example is that you have a matcher for
-`long` and the argument you want to match is `int`. While the two
-types aren't exactly the same, there is nothing really wrong with
-using a `Matcher<long>` to match an `int` - after all, we can first
-convert the `int` argument to a `long` before giving it to the
-matcher.
-
-To support this need, Google Mock gives you the
-`SafeMatcherCast<T>(m)` function. It casts a matcher `m` to type
-`Matcher<T>`. To ensure safety, Google Mock checks that (let `U` be the
-type `m` accepts):
-
- 1. Type `T` can be implicitly cast to type `U`;
- 1. When both `T` and `U` are built-in arithmetic types (`bool`, integers, and floating-point numbers), the conversion from `T` to `U` is not lossy (in other words, any value representable by `T` can also be represented by `U`); and
- 1. When `U` is a reference, `T` must also be a reference (as the underlying matcher may be interested in the address of the `U` value).
-
-The code won't compile if any of these conditions aren't met.
- * `ElementsAre*()` can be used to match _any_ container that implements the STL iterator pattern (i.e. it has a `const_iterator` type and supports `begin()/end()`), not just the ones defined in STL. It will even work with container types yet to be written - as long as they follows the above pattern.
- * You can use nested `ElementsAre*()` to match nested (multi-dimensional) containers.
- * If the container is passed by pointer instead of by reference, just write `Pointee(ElementsAre*(...))`.
- * The order of elements _matters_ for `ElementsAre*()`. Therefore don't use it with containers whose element order is undefined (e.g. `hash_map`).
-
-## Sharing Matchers ##
-
-Under the hood, a Google Mock matcher object consists of a pointer to
-a ref-counted implementation object. Copying matchers is allowed and
-very efficient, as only the pointer is copied. When the last matcher
-that references the implementation object dies, the implementation
-object will be deleted.
-
-Therefore, if you have some complex matcher that you want to use again
-and again, there is no need to build it every time. Just assign it to a
-matcher variable and use that variable repeatedly! For example,
-
-```
- Matcher<int> in_range = AllOf(Gt(5), Le(10));
- ... use in_range as a matcher in multiple EXPECT_CALLs ...
-```
-
-# Setting Expectations #
-
-## Knowing When to Expect ##
-
-`ON_CALL` is likely the single most under-utilized construct in Google Mock.
-
-There are basically two constructs for defining the behavior of a mock object: `ON_CALL` and `EXPECT_CALL`. The difference? `ON_CALL` defines what happens when a mock method is called, but _doesn't imply any expectation on the method being called._ `EXPECT_CALL` not only defines the behavior, but also sets an expectation that _the method will be called with the given arguments, for the given number of times_ (and _in the given order_ when you specify the order too).
-
-Since `EXPECT_CALL` does more, isn't it better than `ON_CALL`? Not really. Every `EXPECT_CALL` adds a constraint on the behavior of the code under test. Having more constraints than necessary is _baaad_ - even worse than not having enough constraints.
-
-This may be counter-intuitive. How could tests that verify more be worse than tests that verify less? Isn't verification the whole point of tests?
-
-The answer, lies in _what_ a test should verify. **A good test verifies the contract of the code.** If a test over-specifies, it doesn't leave enough freedom to the implementation. As a result, changing the implementation without breaking the contract (e.g. refactoring and optimization), which should be perfectly fine to do, can break such tests. Then you have to spend time fixing them, only to see them broken again the next time the implementation is changed.
-
-Keep in mind that one doesn't have to verify more than one property in one test. In fact, **it's a good style to verify only one thing in one test.** If you do that, a bug will likely break only one or two tests instead of dozens (which case would you rather debug?). If you are also in the habit of giving tests descriptive names that tell what they verify, you can often easily guess what's wrong just from the test log itself.
-
-So use `ON_CALL` by default, and only use `EXPECT_CALL` when you actually intend to verify that the call is made. For example, you may have a bunch of `ON_CALL`s in your test fixture to set the common mock behavior shared by all tests in the same group, and write (scarcely) different `EXPECT_CALL`s in different `TEST_F`s to verify different aspects of the code's behavior. Compared with the style where each `TEST` has many `EXPECT_CALL`s, this leads to tests that are more resilient to implementational changes (and thus less likely to require maintenance) and makes the intent of the tests more obvious (so they are easier to maintain when you do need to maintain them).
-
-If you are bothered by the "Uninteresting mock function call" message printed when a mock method without an `EXPECT_CALL` is called, you may use a `NiceMock` instead to suppress all such messages for the mock object, or suppress the message for specific methods by adding `EXPECT_CALL(...).Times(AnyNumber())`. DO NOT suppress it by blindly adding an `EXPECT_CALL(...)`, or you'll have a test that's a pain to maintain.
-
-## Ignoring Uninteresting Calls ##
-
-If you are not interested in how a mock method is called, just don't
-say anything about it. In this case, if the method is ever called,
-Google Mock will perform its default action to allow the test program
-to continue. If you are not happy with the default action taken by
-Google Mock, you can override it using `DefaultValue<T>::Set()`
-(described later in this document) or `ON_CALL()`.
-
-Please note that once you expressed interest in a particular mock
-method (via `EXPECT_CALL()`), all invocations to it must match some
-expectation. If this function is called but the arguments don't match
-any `EXPECT_CALL()` statement, it will be an error.
-
-## Disallowing Unexpected Calls ##
-
-If a mock method shouldn't be called at all, explicitly say so:
-
-```
-using ::testing::_;
-...
- EXPECT_CALL(foo, Bar(_))
- .Times(0);
-```
-
-If some calls to the method are allowed, but the rest are not, just
-list all the expected calls:
-
-```
-using ::testing::AnyNumber;
-using ::testing::Gt;
-...
- EXPECT_CALL(foo, Bar(5));
- EXPECT_CALL(foo, Bar(Gt(10)))
- .Times(AnyNumber());
-```
-
-A call to `foo.Bar()` that doesn't match any of the `EXPECT_CALL()`
-statements will be an error.
-
-## Understanding Uninteresting vs Unexpected Calls ##
-
-_Uninteresting_ calls and _unexpected_ calls are different concepts in Google Mock. _Very_ different.
-
-A call `x.Y(...)` is **uninteresting** if there's _not even a single_ `EXPECT_CALL(x, Y(...))` set. In other words, the test isn't interested in the `x.Y()` method at all, as evident in that the test doesn't care to say anything about it.
-
-A call `x.Y(...)` is **unexpected** if there are some `EXPECT_CALL(x, Y(...))s` set, but none of them matches the call. Put another way, the test is interested in the `x.Y()` method (therefore it _explicitly_ sets some `EXPECT_CALL` to verify how it's called); however, the verification fails as the test doesn't expect this particular call to happen.
-
-**An unexpected call is always an error,** as the code under test doesn't behave the way the test expects it to behave.
-
-**By default, an uninteresting call is not an error,** as it violates no constraint specified by the test. (Google Mock's philosophy is that saying nothing means there is no constraint.) However, it leads to a warning, as it _might_ indicate a problem (e.g. the test author might have forgotten to specify a constraint).
-
-In Google Mock, `NiceMock` and `StrictMock` can be used to make a mock class "nice" or "strict". How does this affect uninteresting calls and unexpected calls?
-
-A **nice mock** suppresses uninteresting call warnings. It is less chatty than the default mock, but otherwise is the same. If a test fails with a default mock, it will also fail using a nice mock instead. And vice versa. Don't expect making a mock nice to change the test's result.
-
-A **strict mock** turns uninteresting call warnings into errors. So making a mock strict may change the test's result.
-The sole `EXPECT_CALL` here says that all calls to `GetDomainOwner()` must have `"google.com"` as the argument. If `GetDomainOwner("yahoo.com")` is called, it will be an unexpected call, and thus an error. Having a nice mock doesn't change the severity of an unexpected call.
-
-So how do we tell Google Mock that `GetDomainOwner()` can be called with some other arguments as well? The standard technique is to add a "catch all" `EXPECT_CALL`:
-
-```
- EXPECT_CALL(mock_registry, GetDomainOwner(_))
- .Times(AnyNumber()); // catches all other calls to this method.
-Remember that `_` is the wildcard matcher that matches anything. With this, if `GetDomainOwner("google.com")` is called, it will do what the second `EXPECT_CALL` says; if it is called with a different argument, it will do what the first `EXPECT_CALL` says.
-
-Note that the order of the two `EXPECT_CALLs` is important, as a newer `EXPECT_CALL` takes precedence over an older one.
-
-For more on uninteresting calls, nice mocks, and strict mocks, read ["The Nice, the Strict, and the Naggy"](#the-nice-the-strict-and-the-naggy).
-
-## Expecting Ordered Calls ##
-
-Although an `EXPECT_CALL()` statement defined earlier takes precedence
-when Google Mock tries to match a function call with an expectation,
-by default calls don't have to happen in the order `EXPECT_CALL()`
-statements are written. For example, if the arguments match the
-matchers in the third `EXPECT_CALL()`, but not those in the first two,
-then the third expectation will be used.
-
-If you would rather have all calls occur in the order of the
-expectations, put the `EXPECT_CALL()` statements in a block where you
-define a variable of type `InSequence`:
-
-```
- using ::testing::_;
- using ::testing::InSequence;
-
- {
- InSequence s;
-
- EXPECT_CALL(foo, DoThis(5));
- EXPECT_CALL(bar, DoThat(_))
- .Times(2);
- EXPECT_CALL(foo, DoThis(6));
- }
-```
-
-In this example, we expect a call to `foo.DoThis(5)`, followed by two
-calls to `bar.DoThat()` where the argument can be anything, which are
-in turn followed by a call to `foo.DoThis(6)`. If a call occurred
-out-of-order, Google Mock will report an error.
-
-## Expecting Partially Ordered Calls ##
-
-Sometimes requiring everything to occur in a predetermined order can
-lead to brittle tests. For example, we may care about `A` occurring
-before both `B` and `C`, but aren't interested in the relative order
-of `B` and `C`. In this case, the test should reflect our real intent,
-instead of being overly constraining.
-
-Google Mock allows you to impose an arbitrary DAG (directed acyclic
-graph) on the calls. One way to express the DAG is to use the
-[After](CheatSheet.md#the-after-clause) clause of `EXPECT_CALL`.
-
-Another way is via the `InSequence()` clause (not the same as the
-`InSequence` class), which we borrowed from jMock 2. It's less
-flexible than `After()`, but more convenient when you have long chains
-of sequential calls, as it doesn't require you to come up with
-different names for the expectations in the chains. Here's how it
-works:
-
-If we view `EXPECT_CALL()` statements as nodes in a graph, and add an
-edge from node A to node B wherever A must occur before B, we can get
-a DAG. We use the term "sequence" to mean a directed path in this
-DAG. Now, if we decompose the DAG into sequences, we just need to know
-which sequences each `EXPECT_CALL()` belongs to in order to be able to
-reconstruct the original DAG.
-
-So, to specify the partial order on the expectations we need to do two
-things: first to define some `Sequence` objects, and then for each
-`EXPECT_CALL()` say which `Sequence` objects it is part
-of. Expectations in the same sequence must occur in the order they are
-written. For example,
-
-```
- using ::testing::Sequence;
-
- Sequence s1, s2;
-
- EXPECT_CALL(foo, A())
- .InSequence(s1, s2);
- EXPECT_CALL(bar, B())
- .InSequence(s1);
- EXPECT_CALL(bar, C())
- .InSequence(s2);
- EXPECT_CALL(foo, D())
- .InSequence(s2);
-```
-
-specifies the following DAG (where `s1` is `A -> B`, and `s2` is `A ->
-C -> D`):
-
-```
- +---> B
- |
- A ---|
- |
- +---> C ---> D
-```
-
-This means that A must occur before B and C, and C must occur before
-D. There's no restriction about the order other than these.
-
-## Controlling When an Expectation Retires ##
-
-When a mock method is called, Google Mock only consider expectations
-that are still active. An expectation is active when created, and
-becomes inactive (aka _retires_) when a call that has to occur later
-has occurred. For example, in
-
-```
- using ::testing::_;
- using ::testing::Sequence;
-
- Sequence s1, s2;
-
- EXPECT_CALL(log, Log(WARNING, _, "File too large.")) // #1
- .Times(AnyNumber())
- .InSequence(s1, s2);
- EXPECT_CALL(log, Log(WARNING, _, "Data set is empty.")) // #2
- .InSequence(s1);
- EXPECT_CALL(log, Log(WARNING, _, "User not found.")) // #3
- .InSequence(s2);
-```
-
-as soon as either #2 or #3 is matched, #1 will retire. If a warning
-`"File too large."` is logged after this, it will be an error.
-
-Note that an expectation doesn't retire automatically when it's
-saturated. For example,
-
-```
-using ::testing::_;
-...
- EXPECT_CALL(log, Log(WARNING, _, _)); // #1
- EXPECT_CALL(log, Log(WARNING, _, "File too large.")); // #2
-```
-
-says that there will be exactly one warning with the message `"File
-too large."`. If the second warning contains this message too, #2 will
-match again and result in an upper-bound-violated error.
-
-If this is not what you want, you can ask an expectation to retire as
-soon as it becomes saturated:
-
-```
-using ::testing::_;
-...
- EXPECT_CALL(log, Log(WARNING, _, _)); // #1
- EXPECT_CALL(log, Log(WARNING, _, "File too large.")) // #2
- .RetiresOnSaturation();
-```
-
-Here #2 can be used only once, so if you have two warnings with the
-message `"File too large."`, the first will match #2 and the second
-will match #1 - there will be no error.
-
-# Using Actions #
-
-## Returning References from Mock Methods ##
-
-If a mock function's return type is a reference, you need to use
-`ReturnRef()` instead of `Return()` to return a result:
-
-```
-using ::testing::ReturnRef;
-
-class MockFoo : public Foo {
- public:
- MOCK_METHOD0(GetBar, Bar&());
-};
-...
-
- MockFoo foo;
- Bar bar;
- EXPECT_CALL(foo, GetBar())
- .WillOnce(ReturnRef(bar));
-```
-
-## Returning Live Values from Mock Methods ##
-
-The `Return(x)` action saves a copy of `x` when the action is
-_created_, and always returns the same value whenever it's
-executed. Sometimes you may want to instead return the _live_ value of
-`x` (i.e. its value at the time when the action is _executed_.).
-
-If the mock function's return type is a reference, you can do it using
-`ReturnRef(x)`, as shown in the previous recipe ("Returning References
-from Mock Methods"). However, Google Mock doesn't let you use
-`ReturnRef()` in a mock function whose return type is not a reference,
-as doing that usually indicates a user error. So, what shall you do?
-
-You may be tempted to try `ByRef()`:
-
-```
-using testing::ByRef;
-using testing::Return;
-
-class MockFoo : public Foo {
- public:
- MOCK_METHOD0(GetValue, int());
-};
-...
- int x = 0;
- MockFoo foo;
- EXPECT_CALL(foo, GetValue())
- .WillRepeatedly(Return(ByRef(x)));
- x = 42;
- EXPECT_EQ(42, foo.GetValue());
-```
-
-Unfortunately, it doesn't work here. The above code will fail with error:
-
-```
-Value of: foo.GetValue()
- Actual: 0
-Expected: 42
-```
-
-The reason is that `Return(value)` converts `value` to the actual
-return type of the mock function at the time when the action is
-_created_, not when it is _executed_. (This behavior was chosen for
-the action to be safe when `value` is a proxy object that references
-some temporary objects.) As a result, `ByRef(x)` is converted to an
-`int` value (instead of a `const int&`) when the expectation is set,
-and `Return(ByRef(x))` will always return 0.
-
-`ReturnPointee(pointer)` was provided to solve this problem
-specifically. It returns the value pointed to by `pointer` at the time
-the action is _executed_:
-
-```
-using testing::ReturnPointee;
-...
- int x = 0;
- MockFoo foo;
- EXPECT_CALL(foo, GetValue())
- .WillRepeatedly(ReturnPointee(&x)); // Note the & here.
- x = 42;
- EXPECT_EQ(42, foo.GetValue()); // This will succeed now.
-```
-
-## Combining Actions ##
-
-Want to do more than one thing when a function is called? That's
-fine. `DoAll()` allow you to do sequence of actions every time. Only
-the return value of the last action in the sequence will be used.
-
-```
-using ::testing::DoAll;
-
-class MockFoo : public Foo {
- public:
- MOCK_METHOD1(Bar, bool(int n));
-};
-...
-
- EXPECT_CALL(foo, Bar(_))
- .WillOnce(DoAll(action_1,
- action_2,
- ...
- action_n));
-```
-
-## Mocking Side Effects ##
-
-Sometimes a method exhibits its effect not via returning a value but
-via side effects. For example, it may change some global state or
-modify an output argument. To mock side effects, in general you can
-define your own action by implementing `::testing::ActionInterface`.
-
-If all you need to do is to change an output argument, the built-in
-## Changing a Mock Object's Behavior Based on the State ##
-
-If you expect a call to change the behavior of a mock object, you can use `::testing::InSequence` to specify different behaviors before and after the call:
-
-```
-using ::testing::InSequence;
-using ::testing::Return;
-
-...
- {
- InSequence seq;
- EXPECT_CALL(my_mock, IsDirty())
- .WillRepeatedly(Return(true));
- EXPECT_CALL(my_mock, Flush());
- EXPECT_CALL(my_mock, IsDirty())
- .WillRepeatedly(Return(false));
- }
- my_mock.FlushIfDirty();
-```
-
-This makes `my_mock.IsDirty()` return `true` before `my_mock.Flush()` is called and return `false` afterwards.
-
-If the behavior change is more complex, you can store the effects in a variable and make a mock method get its return value from that variable:
-For better readability, Google Mock also gives you:
-
- * `WithoutArgs(action)` when the inner `action` takes _no_ argument, and
- * `WithArg<N>(action)` (no `s` after `Arg`) when the inner `action` takes _one_ argument.
-
-As you may have realized, `InvokeWithoutArgs(...)` is just syntactic
-sugar for `WithoutArgs(Invoke(...))`.
-
-Here are more tips:
-
- * The inner action used in `WithArgs` and friends does not have to be `Invoke()` -- it can be anything.
- * You can repeat an argument in the argument list if necessary, e.g. `WithArgs<2, 3, 3, 5>(...)`.
- * You can change the order of the arguments, e.g. `WithArgs<3, 2, 1>(...)`.
- * The types of the selected arguments do _not_ have to match the signature of the inner action exactly. It works as long as they can be implicitly converted to the corresponding arguments of the inner action. For example, if the 4-th argument of the mock function is an `int` and `my_action` takes a `double`, `WithArg<4>(my_action)` will work.
-
-## Ignoring Arguments in Action Functions ##
-
-The selecting-an-action's-arguments recipe showed us one way to make a
-mock function and an action with incompatible argument lists fit
-together. The downside is that wrapping the action in
-`WithArgs<...>()` can get tedious for people writing the tests.
-
-If you are defining a function, method, or functor to be used with
-`Invoke*()`, and you are not interested in some of its arguments, an
-alternative to `WithArgs` is to declare the uninteresting arguments as
-`Unused`. This makes the definition less cluttered and less fragile in
-case the types of the uninteresting arguments change. It could also
-increase the chance the action function can be reused. For example,