866 lines
40 KiB
Markdown
866 lines
40 KiB
Markdown
## gMock Cheat Sheet
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<!-- GOOGLETEST_CM0018 DO NOT DELETE -->
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### Defining a Mock Class
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#### Mocking a Normal Class {#MockClass}
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Given
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```cpp
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class Foo {
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...
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virtual ~Foo();
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virtual int GetSize() const = 0;
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virtual string Describe(const char* name) = 0;
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virtual string Describe(int type) = 0;
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virtual bool Process(Bar elem, int count) = 0;
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};
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```
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(note that `~Foo()` **must** be virtual) we can define its mock as
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```cpp
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#include "gmock/gmock.h"
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class MockFoo : public Foo {
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...
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MOCK_METHOD(int, GetSize, (), (const, override));
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MOCK_METHOD(string, Describe, (const char* name), (override));
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MOCK_METHOD(string, Describe, (int type), (override));
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MOCK_METHOD(bool, Process, (Bar elem, int count), (override));
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};
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```
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To create a "nice" mock, which ignores all uninteresting calls, a "naggy" mock,
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which warns on all uninteresting calls, or a "strict" mock, which treats them as
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failures:
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```cpp
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using ::testing::NiceMock;
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using ::testing::NaggyMock;
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using ::testing::StrictMock;
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NiceMock<MockFoo> nice_foo; // The type is a subclass of MockFoo.
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NaggyMock<MockFoo> naggy_foo; // The type is a subclass of MockFoo.
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StrictMock<MockFoo> strict_foo; // The type is a subclass of MockFoo.
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```
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**Note:** A mock object is currently naggy by default. We may make it nice by
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default in the future.
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#### Mocking a Class Template {#MockTemplate}
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Class templates can be mocked just like any class.
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To mock
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```cpp
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template <typename Elem>
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class StackInterface {
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...
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virtual ~StackInterface();
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virtual int GetSize() const = 0;
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virtual void Push(const Elem& x) = 0;
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};
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```
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(note that all member functions that are mocked, including `~StackInterface()`
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**must** be virtual).
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```cpp
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template <typename Elem>
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class MockStack : public StackInterface<Elem> {
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...
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MOCK_METHOD(int, GetSize, (), (const, override));
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MOCK_METHOD(void, Push, (const Elem& x), (override));
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};
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```
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#### Specifying Calling Conventions for Mock Functions
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If your mock function doesn't use the default calling convention, you can
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specify it by adding `Calltype(convention)` to `MOCK_METHOD`'s 4th parameter.
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For example,
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```cpp
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MOCK_METHOD(bool, Foo, (int n), (Calltype(STDMETHODCALLTYPE)));
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MOCK_METHOD(int, Bar, (double x, double y),
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(const, Calltype(STDMETHODCALLTYPE)));
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```
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where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows.
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### Using Mocks in Tests {#UsingMocks}
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The typical work flow is:
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1. Import the gMock names you need to use. All gMock symbols are in the
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`testing` namespace unless they are macros or otherwise noted.
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2. Create the mock objects.
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3. Optionally, set the default actions of the mock objects.
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4. Set your expectations on the mock objects (How will they be called? What
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will they do?).
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5. Exercise code that uses the mock objects; if necessary, check the result
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using googletest assertions.
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6. When a mock object is destructed, gMock automatically verifies that all
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expectations on it have been satisfied.
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Here's an example:
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```cpp
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using ::testing::Return; // #1
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TEST(BarTest, DoesThis) {
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MockFoo foo; // #2
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ON_CALL(foo, GetSize()) // #3
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.WillByDefault(Return(1));
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// ... other default actions ...
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EXPECT_CALL(foo, Describe(5)) // #4
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.Times(3)
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.WillRepeatedly(Return("Category 5"));
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// ... other expectations ...
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EXPECT_EQ("good", MyProductionFunction(&foo)); // #5
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} // #6
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```
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### Setting Default Actions {#OnCall}
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gMock has a **built-in default action** for any function that returns `void`,
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`bool`, a numeric value, or a pointer. In C++11, it will additionally returns
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the default-constructed value, if one exists for the given type.
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To customize the default action for functions with return type *`T`*:
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```cpp
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using ::testing::DefaultValue;
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// Sets the default value to be returned. T must be CopyConstructible.
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DefaultValue<T>::Set(value);
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// Sets a factory. Will be invoked on demand. T must be MoveConstructible.
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// T MakeT();
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DefaultValue<T>::SetFactory(&MakeT);
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// ... use the mocks ...
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// Resets the default value.
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DefaultValue<T>::Clear();
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```
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Example usage:
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```cpp
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// Sets the default action for return type std::unique_ptr<Buzz> to
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// creating a new Buzz every time.
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DefaultValue<std::unique_ptr<Buzz>>::SetFactory(
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[] { return MakeUnique<Buzz>(AccessLevel::kInternal); });
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// When this fires, the default action of MakeBuzz() will run, which
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// will return a new Buzz object.
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EXPECT_CALL(mock_buzzer_, MakeBuzz("hello")).Times(AnyNumber());
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auto buzz1 = mock_buzzer_.MakeBuzz("hello");
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auto buzz2 = mock_buzzer_.MakeBuzz("hello");
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EXPECT_NE(nullptr, buzz1);
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EXPECT_NE(nullptr, buzz2);
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EXPECT_NE(buzz1, buzz2);
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// Resets the default action for return type std::unique_ptr<Buzz>,
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// to avoid interfere with other tests.
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DefaultValue<std::unique_ptr<Buzz>>::Clear();
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```
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To customize the default action for a particular method of a specific mock
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object, use `ON_CALL()`. `ON_CALL()` has a similar syntax to `EXPECT_CALL()`,
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but it is used for setting default behaviors (when you do not require that the
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mock method is called). See go/prefer-on-call for a more detailed discussion.
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```cpp
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ON_CALL(mock-object, method(matchers))
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.With(multi-argument-matcher) ?
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.WillByDefault(action);
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```
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### Setting Expectations {#ExpectCall}
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`EXPECT_CALL()` sets **expectations** on a mock method (How will it be called?
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What will it do?):
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```cpp
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EXPECT_CALL(mock-object, method (matchers)?)
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.With(multi-argument-matcher) ?
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.Times(cardinality) ?
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.InSequence(sequences) *
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.After(expectations) *
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.WillOnce(action) *
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.WillRepeatedly(action) ?
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.RetiresOnSaturation(); ?
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```
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If `(matchers)` is omitted, the expectation is the same as if the matchers were
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set to anything matchers (for example, `(_, _, _, _)` for a four-arg method).
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If `Times()` is omitted, the cardinality is assumed to be:
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* `Times(1)` when there is neither `WillOnce()` nor `WillRepeatedly()`;
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* `Times(n)` when there are `n` `WillOnce()`s but no `WillRepeatedly()`, where
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`n` >= 1; or
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* `Times(AtLeast(n))` when there are `n` `WillOnce()`s and a
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`WillRepeatedly()`, where `n` >= 0.
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A method with no `EXPECT_CALL()` is free to be invoked *any number of times*,
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and the default action will be taken each time.
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### Matchers {#MatcherList}
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<!-- GOOGLETEST_CM0019 DO NOT DELETE -->
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A **matcher** matches a *single* argument. You can use it inside `ON_CALL()` or
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`EXPECT_CALL()`, or use it to validate a value directly:
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| Matcher | Description |
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| :----------------------------------- | :------------------------------------ |
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| `EXPECT_THAT(actual_value, matcher)` | Asserts that `actual_value` matches |
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: : `matcher`. :
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| `ASSERT_THAT(actual_value, matcher)` | The same as |
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: : `EXPECT_THAT(actual_value, matcher)`, :
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: : except that it generates a **fatal** :
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: : failure. :
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Built-in matchers (where `argument` is the function argument) are divided into
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several categories:
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## Wildcard
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Matcher | Description
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:-------------------------- | :-----------------------------------------------
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`_` | `argument` can be any value of the correct type.
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`A<type>()` or `An<type>()` | `argument` can be any value of type `type`.
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#### Generic Comparison
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| Matcher | Description |
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| :--------------------- | :-------------------------------------------------- |
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| `Eq(value)` or `value` | `argument == value` |
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| `Ge(value)` | `argument >= value` |
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| `Gt(value)` | `argument > value` |
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| `Le(value)` | `argument <= value` |
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| `Lt(value)` | `argument < value` |
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| `Ne(value)` | `argument != value` |
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| `IsNull()` | `argument` is a `NULL` pointer (raw or smart). |
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| `NotNull()` | `argument` is a non-null pointer (raw or smart). |
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| `Optional(m)` | `argument` is `optional<>` that contains a value |
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: : matching `m`. :
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| `VariantWith<T>(m)` | `argument` is `variant<>` that holds the |
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: : alternative of type T with a value matching `m`. :
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| `Ref(variable)` | `argument` is a reference to `variable`. |
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| `TypedEq<type>(value)` | `argument` has type `type` and is equal to `value`. |
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: : You may need to use this instead of `Eq(value)` :
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: : when the mock function is overloaded. :
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Except `Ref()`, these matchers make a *copy* of `value` in case it's modified or
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destructed later. If the compiler complains that `value` doesn't have a public
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copy constructor, try wrap it in `ByRef()`, e.g.
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`Eq(ByRef(non_copyable_value))`. If you do that, make sure `non_copyable_value`
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is not changed afterwards, or the meaning of your matcher will be changed.
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#### Floating-Point Matchers {#FpMatchers}
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| Matcher | Description |
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| :------------------------------- | :--------------------------------- |
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| `DoubleEq(a_double)` | `argument` is a `double` value |
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: : approximately equal to `a_double`, :
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: : treating two NaNs as unequal. :
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| `FloatEq(a_float)` | `argument` is a `float` value |
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: : approximately equal to `a_float`, :
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: : treating two NaNs as unequal. :
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| `NanSensitiveDoubleEq(a_double)` | `argument` is a `double` value |
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: : approximately equal to `a_double`, :
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: : treating two NaNs as equal. :
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| `NanSensitiveFloatEq(a_float)` | `argument` is a `float` value |
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: : approximately equal to `a_float`, :
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: : treating two NaNs as equal. :
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The above matchers use ULP-based comparison (the same as used in googletest).
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They automatically pick a reasonable error bound based on the absolute value of
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the expected value. `DoubleEq()` and `FloatEq()` conform to the IEEE standard,
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which requires comparing two NaNs for equality to return false. The
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`NanSensitive*` version instead treats two NaNs as equal, which is often what a
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user wants.
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| Matcher | Description |
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| :---------------------------------- | :------------------------------------- |
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| `DoubleNear(a_double, | `argument` is a `double` value close |
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: max_abs_error)` : to `a_double` (absolute error <= :
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: : `max_abs_error`), treating two NaNs as :
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: : unequal. :
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| `FloatNear(a_float, max_abs_error)` | `argument` is a `float` value close to |
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: : `a_float` (absolute error <= :
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: : `max_abs_error`), treating two NaNs as :
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: : unequal. :
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| `NanSensitiveDoubleNear(a_double, | `argument` is a `double` value close |
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: max_abs_error)` : to `a_double` (absolute error <= :
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: : `max_abs_error`), treating two NaNs as :
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: : equal. :
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| `NanSensitiveFloatNear(a_float, | `argument` is a `float` value close to |
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: max_abs_error)` : `a_float` (absolute error <= :
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: : `max_abs_error`), treating two NaNs as :
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: : equal. :
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#### String Matchers
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The `argument` can be either a C string or a C++ string object:
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| Matcher | Description |
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| :---------------------- | :------------------------------------------------- |
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| `ContainsRegex(string)` | `argument` matches the given regular expression. |
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| `EndsWith(suffix)` | `argument` ends with string `suffix`. |
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| `HasSubstr(string)` | `argument` contains `string` as a sub-string. |
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| `MatchesRegex(string)` | `argument` matches the given regular expression |
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: : with the match starting at the first character and :
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: : ending at the last character. :
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| `StartsWith(prefix)` | `argument` starts with string `prefix`. |
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| `StrCaseEq(string)` | `argument` is equal to `string`, ignoring case. |
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| `StrCaseNe(string)` | `argument` is not equal to `string`, ignoring |
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: : case. :
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| `StrEq(string)` | `argument` is equal to `string`. |
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| `StrNe(string)` | `argument` is not equal to `string`. |
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`ContainsRegex()` and `MatchesRegex()` take ownership of the `RE` object. They
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use the regular expression syntax defined
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[here](http://go/gunit-advanced-regex). `StrCaseEq()`, `StrCaseNe()`, `StrEq()`,
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and `StrNe()` work for wide strings as well.
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#### Container Matchers
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Most STL-style containers support `==`, so you can use `Eq(expected_container)`
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or simply `expected_container` to match a container exactly. If you want to
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write the elements in-line, match them more flexibly, or get more informative
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messages, you can use:
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| Matcher | Description |
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| :----------------------------------- | :----------------------------------- |
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| `ContainerEq(container)` | The same as `Eq(container)` except |
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: : that the failure message also :
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: : includes which elements are in one :
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: : container but not the other. :
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| `Contains(e)` | `argument` contains an element that |
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: : matches `e`, which can be either a :
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: : value or a matcher. :
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| `Each(e)` | `argument` is a container where |
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: : _every_ element matches `e`, which :
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: : can be either a value or a matcher. :
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| `ElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, |
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: : where the i-th element matches `ei`, :
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: : which can be a value or a matcher. 0 :
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: : to 10 arguments are allowed. :
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| `ElementsAreArray({ e0, e1, ..., en | The same as `ElementsAre()` except |
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: })`, `ElementsAreArray(array)`, or : that the expected element :
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: `ElementsAreArray(array, count)` : values/matchers come from an :
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: : initializer list, STL-style :
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: : container, or C-style array. :
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| `IsEmpty()` | `argument` is an empty container |
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: : (`container.empty()`). :
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| `Pointwise(m, container)` | `argument` contains the same number |
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: : of elements as in `container`, and :
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: : for all i, (the i-th element in :
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: : `argument`, the i-th element in :
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: : `container`) match `m`, which is a :
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: : matcher on 2-tuples. E.g. :
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: : `Pointwise(Le(), upper_bounds)` :
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: : verifies that each element in :
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: : `argument` doesn't exceed the :
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: : corresponding element in :
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: : `upper_bounds`. See more detail :
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: : below. :
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| `SizeIs(m)` | `argument` is a container whose size |
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: : matches `m`. E.g. `SizeIs(2)` or :
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: : `SizeIs(Lt(2))`. :
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| `UnorderedElementsAre(e0, e1, ..., | `argument` has `n + 1` elements, and |
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: en)` : under some permutation each element :
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: : matches an `ei` (for a different :
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: : `i`), which can be a value or a :
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: : matcher. 0 to 10 arguments are :
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: : allowed. :
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| `UnorderedElementsAreArray({ e0, e1, | The same as `UnorderedElementsAre()` |
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: ..., en })`, : except that the expected element :
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: `UnorderedElementsAreArray(array)`, : values/matchers come from an :
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: or `UnorderedElementsAreArray(array, : initializer list, STL-style :
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: count)` : container, or C-style array. :
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| `WhenSorted(m)` | When `argument` is sorted using the |
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: : `<` operator, it matches container :
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: : matcher `m`. E.g. :
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: : `WhenSorted(ElementsAre(1, 2, 3))` :
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: : verifies that `argument` contains :
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: : elements `1`, `2`, and `3`, ignoring :
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: : order. :
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| `WhenSortedBy(comparator, m)` | The same as `WhenSorted(m)`, except |
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: : that the given comparator instead of :
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: : `<` is used to sort `argument`. E.g. :
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: : `WhenSortedBy(std\:\:greater<int>(), :
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: : ElementsAre(3, 2, 1))`. :
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**Notes:**
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* These matchers can also match:
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1. a native array passed by reference (e.g. in `Foo(const int (&a)[5])`),
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and
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2. an array passed as a pointer and a count (e.g. in `Bar(const T* buffer,
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int len)` -- see [Multi-argument Matchers](#MultiArgMatchers)).
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* The array being matched may be multi-dimensional (i.e. its elements can be
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arrays).
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* `m` in `Pointwise(m, ...)` should be a matcher for `::std::tuple<T, U>`
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where `T` and `U` are the element type of the actual container and the
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expected container, respectively. For example, to compare two `Foo`
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containers where `Foo` doesn't support `operator==`, one might write:
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```cpp
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using ::std::get;
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MATCHER(FooEq, "") {
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return std::get<0>(arg).Equals(std::get<1>(arg));
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}
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...
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EXPECT_THAT(actual_foos, Pointwise(FooEq(), expected_foos));
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```
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#### Member Matchers
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| Matcher | Description |
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| :------------------------------ | :----------------------------------------- |
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| `Field(&class::field, m)` | `argument.field` (or `argument->field` |
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: : when `argument` is a plain pointer) :
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: : matches matcher `m`, where `argument` is :
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: : an object of type _class_. :
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| `Key(e)` | `argument.first` matches `e`, which can be |
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: : either a value or a matcher. E.g. :
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: : `Contains(Key(Le(5)))` can verify that a :
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: : `map` contains a key `<= 5`. :
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| `Pair(m1, m2)` | `argument` is an `std::pair` whose `first` |
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: : field matches `m1` and `second` field :
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: : matches `m2`. :
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| `Property(&class::property, m)` | `argument.property()` (or |
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: : `argument->property()` when `argument` is :
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: : a plain pointer) matches matcher `m`, :
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: : where `argument` is an object of type :
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: : _class_. :
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#### Matching the Result of a Function, Functor, or Callback
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| Matcher | Description |
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| :--------------- | :------------------------------------------------ |
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| `ResultOf(f, m)` | `f(argument)` matches matcher `m`, where `f` is a |
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: : function or functor. :
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#### Pointer Matchers
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| Matcher | Description |
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|
| :------------------------ | :---------------------------------------------- |
|
|
| `Pointee(m)` | `argument` (either a smart pointer or a raw |
|
|
: : pointer) points to a value that matches matcher :
|
|
: : `m`. :
|
|
| `WhenDynamicCastTo<T>(m)` | when `argument` is passed through |
|
|
: : `dynamic_cast<T>()`, it matches matcher `m`. :
|
|
|
|
#### Multi-argument Matchers {#MultiArgMatchers}
|
|
|
|
Technically, all matchers match a *single* value. A "multi-argument" matcher is
|
|
just one that matches a *tuple*. The following matchers can be used to match a
|
|
tuple `(x, y)`:
|
|
|
|
Matcher | Description
|
|
:------ | :----------
|
|
`Eq()` | `x == y`
|
|
`Ge()` | `x >= y`
|
|
`Gt()` | `x > y`
|
|
`Le()` | `x <= y`
|
|
`Lt()` | `x < y`
|
|
`Ne()` | `x != y`
|
|
|
|
You can use the following selectors to pick a subset of the arguments (or
|
|
reorder them) to participate in the matching:
|
|
|
|
| Matcher | Description |
|
|
| :------------------------- | :---------------------------------------------- |
|
|
| `AllArgs(m)` | Equivalent to `m`. Useful as syntactic sugar in |
|
|
: : `.With(AllArgs(m))`. :
|
|
| `Args<N1, N2, ..., Nk>(m)` | The tuple of the `k` selected (using 0-based |
|
|
: : indices) arguments matches `m`, e.g. `Args<1, :
|
|
: : 2>(Eq())`. :
|
|
|
|
#### Composite Matchers
|
|
|
|
You can make a matcher from one or more other matchers:
|
|
|
|
| Matcher | Description |
|
|
| :----------------------- | :---------------------------------------------- |
|
|
| `AllOf(m1, m2, ..., mn)` | `argument` matches all of the matchers `m1` to |
|
|
: : `mn`. :
|
|
| `AnyOf(m1, m2, ..., mn)` | `argument` matches at least one of the matchers |
|
|
: : `m1` to `mn`. :
|
|
| `Not(m)` | `argument` doesn't match matcher `m`. |
|
|
|
|
#### Adapters for Matchers
|
|
|
|
| Matcher | Description |
|
|
| :---------------------- | :------------------------------------ |
|
|
| `MatcherCast<T>(m)` | casts matcher `m` to type |
|
|
: : `Matcher<T>`. :
|
|
| `SafeMatcherCast<T>(m)` | [safely |
|
|
: : casts](cook_book.md#casting-matchers) :
|
|
: : matcher `m` to type `Matcher<T>`. :
|
|
| `Truly(predicate)` | `predicate(argument)` returns |
|
|
: : something considered by C++ to be :
|
|
: : true, where `predicate` is a function :
|
|
: : or functor. :
|
|
|
|
`AddressSatisfies(callback)` and `Truly(callback)` take ownership of `callback`,
|
|
which must be a permanent callback.
|
|
|
|
#### Matchers as Predicates {#MatchersAsPredicatesCheat}
|
|
|
|
| Matcher | Description |
|
|
| :---------------------------- | :------------------------------------------ |
|
|
| `Matches(m)(value)` | evaluates to `true` if `value` matches `m`. |
|
|
: : You can use `Matches(m)` alone as a unary :
|
|
: : functor. :
|
|
| `ExplainMatchResult(m, value, | evaluates to `true` if `value` matches `m`, |
|
|
: result_listener)` : explaining the result to `result_listener`. :
|
|
| `Value(value, m)` | evaluates to `true` if `value` matches `m`. |
|
|
|
|
#### Defining Matchers
|
|
|
|
| Matcher | Description |
|
|
| :----------------------------------- | :------------------------------------ |
|
|
| `MATCHER(IsEven, "") { return (arg % | Defines a matcher `IsEven()` to match |
|
|
: 2) == 0; }` : an even number. :
|
|
| `MATCHER_P(IsDivisibleBy, n, "") { | Defines a macher `IsDivisibleBy(n)` |
|
|
: *result_listener << "where the : to match a number divisible by `n`. :
|
|
: remainder is " << (arg % n); return : :
|
|
: (arg % n) == 0; }` : :
|
|
| `MATCHER_P2(IsBetween, a, b, | Defines a matcher `IsBetween(a, b)` |
|
|
: std\:\:string(negation ? "isn't" \: : to match a value in the range [`a`, :
|
|
: "is") + " between " + : `b`]. :
|
|
: PrintToString(a) + " and " + : :
|
|
: PrintToString(b)) { return a <= arg : :
|
|
: && arg <= b; }` : :
|
|
|
|
**Notes:**
|
|
|
|
1. The `MATCHER*` macros cannot be used inside a function or class.
|
|
1. The matcher body must be *purely functional* (i.e. it cannot have any side
|
|
effect, and the result must not depend on anything other than the value
|
|
being matched and the matcher parameters).
|
|
1. You can use `PrintToString(x)` to convert a value `x` of any type to a
|
|
string.
|
|
|
|
## Matchers as Test Assertions
|
|
|
|
Matcher | Description
|
|
:--------------------------- | :----------
|
|
`ASSERT_THAT(expression, m)` | Generates a [fatal failure](../../googletest/docs/primer.md#assertions) if the value of `expression` doesn't match matcher `m`.
|
|
`EXPECT_THAT(expression, m)` | Generates a non-fatal failure if the value of `expression` doesn't match matcher `m`.
|
|
|
|
### Actions {#ActionList}
|
|
|
|
**Actions** specify what a mock function should do when invoked.
|
|
|
|
#### Returning a Value
|
|
|
|
| Matcher | Description |
|
|
| :-------------------------- | :-------------------------------------------- |
|
|
| `Return()` | Return from a `void` mock function. |
|
|
| `Return(value)` | Return `value`. If the type of `value` is |
|
|
: : different to the mock function's return type, :
|
|
: : `value` is converted to the latter type <i>at :
|
|
: : the time the expectation is set</i>, not when :
|
|
: : the action is executed. :
|
|
| `ReturnArg<N>()` | Return the `N`-th (0-based) argument. |
|
|
| `ReturnNew<T>(a1, ..., ak)` | Return `new T(a1, ..., ak)`; a different |
|
|
: : object is created each time. :
|
|
| `ReturnNull()` | Return a null pointer. |
|
|
| `ReturnPointee(ptr)` | Return the value pointed to by `ptr`. |
|
|
| `ReturnRef(variable)` | Return a reference to `variable`. |
|
|
| `ReturnRefOfCopy(value)` | Return a reference to a copy of `value`; the |
|
|
: : copy lives as long as the action. :
|
|
|
|
#### Side Effects
|
|
|
|
| Matcher | Description |
|
|
| :--------------------------------- | :-------------------------------------- |
|
|
| `Assign(&variable, value)` | Assign `value` to variable. |
|
|
| `DeleteArg<N>()` | Delete the `N`-th (0-based) argument, |
|
|
: : which must be a pointer. :
|
|
| `SaveArg<N>(pointer)` | Save the `N`-th (0-based) argument to |
|
|
: : `*pointer`. :
|
|
| `SaveArgPointee<N>(pointer)` | Save the value pointed to by the `N`-th |
|
|
: : (0-based) argument to `*pointer`. :
|
|
| `SetArgReferee<N>(value)` | Assign value to the variable referenced |
|
|
: : by the `N`-th (0-based) argument. :
|
|
| `SetArgPointee<N>(value)` | Assign `value` to the variable pointed |
|
|
: : by the `N`-th (0-based) argument. :
|
|
| `SetArgumentPointee<N>(value)` | Same as `SetArgPointee<N>(value)`. |
|
|
: : Deprecated. Will be removed in v1.7.0. :
|
|
| `SetArrayArgument<N>(first, last)` | Copies the elements in source range |
|
|
: : [`first`, `last`) to the array pointed :
|
|
: : to by the `N`-th (0-based) argument, :
|
|
: : which can be either a pointer or an :
|
|
: : iterator. The action does not take :
|
|
: : ownership of the elements in the source :
|
|
: : range. :
|
|
| `SetErrnoAndReturn(error, value)` | Set `errno` to `error` and return |
|
|
: : `value`. :
|
|
| `Throw(exception)` | Throws the given exception, which can |
|
|
: : be any copyable value. Available since :
|
|
: : v1.1.0. :
|
|
|
|
#### Using a Function, Functor, Lambda, or Callback as an Action
|
|
|
|
In the following, by "callable" we mean a free function, `std::function`,
|
|
functor, lambda, or `google3`-style permanent callback.
|
|
|
|
| Matcher | Description |
|
|
| :---------------------------------- | :------------------------------------- |
|
|
| `Invoke(f)` | Invoke `f` with the arguments passed |
|
|
: : to the mock function, where `f` can be :
|
|
: : a global/static function or a functor. :
|
|
| `Invoke(object_pointer, | Invoke the {method on the object with |
|
|
: &class\:\:method)` : the arguments passed to the mock :
|
|
: : function. :
|
|
| `InvokeWithoutArgs(f)` | Invoke `f`, which can be a |
|
|
: : global/static function or a functor. :
|
|
: : `f` must take no arguments. :
|
|
| `InvokeWithoutArgs(object_pointer, | Invoke the method on the object, which |
|
|
: &class\:\:method)` : takes no arguments. :
|
|
| `InvokeArgument<N>(arg1, arg2, ..., | Invoke the mock function's `N`-th |
|
|
: argk)` : (0-based) argument, which must be a :
|
|
: : function or a functor, with the `k` :
|
|
: : arguments. :
|
|
|
|
The return value of the invoked function is used as the return value of the
|
|
action.
|
|
|
|
When defining a callable to be used with `Invoke*()`, you can declare any unused
|
|
parameters as `Unused`:
|
|
|
|
```cpp
|
|
using ::testing::Invoke;
|
|
double Distance(Unused, double x, double y) { return sqrt(x*x + y*y); }
|
|
...
|
|
EXPECT_CALL(mock, Foo("Hi", _, _)).WillOnce(Invoke(Distance));
|
|
```
|
|
|
|
`Invoke(callback)` and `InvokeWithoutArgs(callback)` take ownership of
|
|
`callback`, which must be permanent. The type of `callback` must be a base
|
|
callback type instead of a derived one, e.g.
|
|
|
|
```cpp
|
|
BlockingClosure* done = new BlockingClosure;
|
|
... Invoke(done) ...; // This won't compile!
|
|
|
|
Closure* done2 = new BlockingClosure;
|
|
... Invoke(done2) ...; // This works.
|
|
```
|
|
|
|
In `InvokeArgument<N>(...)`, if an argument needs to be passed by reference,
|
|
wrap it inside `ByRef()`. For example,
|
|
|
|
```cpp
|
|
using ::testing::ByRef;
|
|
using ::testing::InvokeArgument;
|
|
...
|
|
InvokeArgument<2>(5, string("Hi"), ByRef(foo))
|
|
```
|
|
|
|
calls the mock function's #2 argument, passing to it `5` and `string("Hi")` by
|
|
value, and `foo` by reference.
|
|
|
|
## Default Action
|
|
|
|
| Matcher | Description |
|
|
| :------------ | :----------------------------------------------------- |
|
|
| `DoDefault()` | Do the default action (specified by `ON_CALL()` or the |
|
|
: : built-in one). :
|
|
|
|
**Note:** due to technical reasons, `DoDefault()` cannot be used inside a
|
|
composite action - trying to do so will result in a run-time error.
|
|
|
|
## Composite Actions
|
|
|
|
| Matcher | Description |
|
|
| :----------------------------- | :------------------------------------------ |
|
|
| `DoAll(a1, a2, ..., an)` | Do all actions `a1` to `an` and return the |
|
|
: : result of `an` in each invocation. The :
|
|
: : first `n - 1` sub-actions must return void. :
|
|
| `IgnoreResult(a)` | Perform action `a` and ignore its result. |
|
|
: : `a` must not return void. :
|
|
| `WithArg<N>(a)` | Pass the `N`-th (0-based) argument of the |
|
|
: : mock function to action `a` and perform it. :
|
|
| `WithArgs<N1, N2, ..., Nk>(a)` | Pass the selected (0-based) arguments of |
|
|
: : the mock function to action `a` and perform :
|
|
: : it. :
|
|
| `WithoutArgs(a)` | Perform action `a` without any arguments. |
|
|
|
|
## Defining Actions
|
|
|
|
| Matcher | Description |
|
|
| :--------------------------------- | :-------------------------------------- |
|
|
| `ACTION(Sum) { return arg0 + arg1; | Defines an action `Sum()` to return the |
|
|
: }` : sum of the mock function's argument #0 :
|
|
: : and #1. :
|
|
| `ACTION_P(Plus, n) { return arg0 + | Defines an action `Plus(n)` to return |
|
|
: n; }` : the sum of the mock function's :
|
|
: : argument #0 and `n`. :
|
|
| `ACTION_Pk(Foo, p1, ..., pk) { | Defines a parameterized action `Foo(p1, |
|
|
: statements; }` : ..., pk)` to execute the given :
|
|
: : `statements`. :
|
|
|
|
The `ACTION*` macros cannot be used inside a function or class.
|
|
|
|
### Cardinalities {#CardinalityList}
|
|
|
|
These are used in `Times()` to specify how many times a mock function will be
|
|
called:
|
|
|
|
| Matcher | Description |
|
|
| :---------------- | :----------------------------------------------------- |
|
|
| `AnyNumber()` | The function can be called any number of times. |
|
|
| `AtLeast(n)` | The call is expected at least `n` times. |
|
|
| `AtMost(n)` | The call is expected at most `n` times. |
|
|
| `Between(m, n)` | The call is expected between `m` and `n` (inclusive) |
|
|
: : times. :
|
|
| `Exactly(n) or n` | The call is expected exactly `n` times. In particular, |
|
|
: : the call should never happen when `n` is 0. :
|
|
|
|
### Expectation Order
|
|
|
|
By default, the expectations can be matched in *any* order. If some or all
|
|
expectations must be matched in a given order, there are two ways to specify it.
|
|
They can be used either independently or together.
|
|
|
|
#### The After Clause {#AfterClause}
|
|
|
|
```cpp
|
|
using ::testing::Expectation;
|
|
...
|
|
Expectation init_x = EXPECT_CALL(foo, InitX());
|
|
Expectation init_y = EXPECT_CALL(foo, InitY());
|
|
EXPECT_CALL(foo, Bar())
|
|
.After(init_x, init_y);
|
|
```
|
|
|
|
says that `Bar()` can be called only after both `InitX()` and `InitY()` have
|
|
been called.
|
|
|
|
If you don't know how many pre-requisites an expectation has when you write it,
|
|
you can use an `ExpectationSet` to collect them:
|
|
|
|
```cpp
|
|
using ::testing::ExpectationSet;
|
|
...
|
|
ExpectationSet all_inits;
|
|
for (int i = 0; i < element_count; i++) {
|
|
all_inits += EXPECT_CALL(foo, InitElement(i));
|
|
}
|
|
EXPECT_CALL(foo, Bar())
|
|
.After(all_inits);
|
|
```
|
|
|
|
says that `Bar()` can be called only after all elements have been initialized
|
|
(but we don't care about which elements get initialized before the others).
|
|
|
|
Modifying an `ExpectationSet` after using it in an `.After()` doesn't affect the
|
|
meaning of the `.After()`.
|
|
|
|
#### Sequences {#UsingSequences}
|
|
|
|
When you have a long chain of sequential expectations, it's easier to specify
|
|
the order using **sequences**, which don't require you to given each expectation
|
|
in the chain a different name. *All expected calls* in the same sequence must
|
|
occur in the order they are specified.
|
|
|
|
```cpp
|
|
using ::testing::Return;
|
|
using ::testing::Sequence;
|
|
Sequence s1, s2;
|
|
...
|
|
EXPECT_CALL(foo, Reset())
|
|
.InSequence(s1, s2)
|
|
.WillOnce(Return(true));
|
|
EXPECT_CALL(foo, GetSize())
|
|
.InSequence(s1)
|
|
.WillOnce(Return(1));
|
|
EXPECT_CALL(foo, Describe(A<const char*>()))
|
|
.InSequence(s2)
|
|
.WillOnce(Return("dummy"));
|
|
```
|
|
|
|
says that `Reset()` must be called before *both* `GetSize()` *and* `Describe()`,
|
|
and the latter two can occur in any order.
|
|
|
|
To put many expectations in a sequence conveniently:
|
|
|
|
```cpp
|
|
using ::testing::InSequence;
|
|
{
|
|
InSequence seq;
|
|
|
|
EXPECT_CALL(...)...;
|
|
EXPECT_CALL(...)...;
|
|
...
|
|
EXPECT_CALL(...)...;
|
|
}
|
|
```
|
|
|
|
says that all expected calls in the scope of `seq` must occur in strict order.
|
|
The name `seq` is irrelevant.
|
|
|
|
### Verifying and Resetting a Mock
|
|
|
|
gMock will verify the expectations on a mock object when it is destructed, or
|
|
you can do it earlier:
|
|
|
|
```cpp
|
|
using ::testing::Mock;
|
|
...
|
|
// Verifies and removes the expectations on mock_obj;
|
|
// returns true iff successful.
|
|
Mock::VerifyAndClearExpectations(&mock_obj);
|
|
...
|
|
// Verifies and removes the expectations on mock_obj;
|
|
// also removes the default actions set by ON_CALL();
|
|
// returns true iff successful.
|
|
Mock::VerifyAndClear(&mock_obj);
|
|
```
|
|
|
|
You can also tell gMock that a mock object can be leaked and doesn't need to be
|
|
verified:
|
|
|
|
```cpp
|
|
Mock::AllowLeak(&mock_obj);
|
|
```
|
|
|
|
### Mock Classes
|
|
|
|
gMock defines a convenient mock class template
|
|
|
|
```cpp
|
|
class MockFunction<R(A1, ..., An)> {
|
|
public:
|
|
MOCK_METHOD(R, Call, (A1, ..., An));
|
|
};
|
|
```
|
|
|
|
See this [recipe](cook_book.md#using-check-points) for one application of it.
|
|
|
|
### Flags
|
|
|
|
| Flag | Description |
|
|
| :----------------------------- | :---------------------------------------- |
|
|
| `--gmock_catch_leaked_mocks=0` | Don't report leaked mock objects as |
|
|
: : failures. :
|
|
| `--gmock_verbose=LEVEL` | Sets the default verbosity level (`info`, |
|
|
: : `warning`, or `error`) of Google Mock :
|
|
: : messages. :
|