Changeset View
Changeset View
Standalone View
Standalone View
google/googletest/dist/googlemock/docs/CheatSheet.md
- This file was added.
# Defining a Mock Class # | |||||
## Mocking a Normal Class ## | |||||
Given | |||||
``` | |||||
class Foo { | |||||
... | |||||
virtual ~Foo(); | |||||
virtual int GetSize() const = 0; | |||||
virtual string Describe(const char* name) = 0; | |||||
virtual string Describe(int type) = 0; | |||||
virtual bool Process(Bar elem, int count) = 0; | |||||
}; | |||||
``` | |||||
(note that `~Foo()` **must** be virtual) we can define its mock as | |||||
``` | |||||
#include "gmock/gmock.h" | |||||
class MockFoo : public Foo { | |||||
MOCK_CONST_METHOD0(GetSize, int()); | |||||
MOCK_METHOD1(Describe, string(const char* name)); | |||||
MOCK_METHOD1(Describe, string(int type)); | |||||
MOCK_METHOD2(Process, bool(Bar elem, int count)); | |||||
}; | |||||
``` | |||||
To create a "nice" mock object which ignores all uninteresting calls, | |||||
or a "strict" mock object, which treats them as failures: | |||||
``` | |||||
NiceMock<MockFoo> nice_foo; // The type is a subclass of MockFoo. | |||||
StrictMock<MockFoo> strict_foo; // The type is a subclass of MockFoo. | |||||
``` | |||||
## Mocking a Class Template ## | |||||
To mock | |||||
``` | |||||
template <typename Elem> | |||||
class StackInterface { | |||||
public: | |||||
... | |||||
virtual ~StackInterface(); | |||||
virtual int GetSize() const = 0; | |||||
virtual void Push(const Elem& x) = 0; | |||||
}; | |||||
``` | |||||
(note that `~StackInterface()` **must** be virtual) just append `_T` to the `MOCK_*` macros: | |||||
``` | |||||
template <typename Elem> | |||||
class MockStack : public StackInterface<Elem> { | |||||
public: | |||||
... | |||||
MOCK_CONST_METHOD0_T(GetSize, int()); | |||||
MOCK_METHOD1_T(Push, void(const Elem& x)); | |||||
}; | |||||
``` | |||||
## Specifying Calling Conventions for Mock Functions ## | |||||
If your mock function doesn't use the default calling convention, you | |||||
can specify it by appending `_WITH_CALLTYPE` to any of the macros | |||||
described in the previous two sections and supplying the calling | |||||
convention as the first argument to the macro. For example, | |||||
``` | |||||
MOCK_METHOD1_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int n)); | |||||
MOCK_CONST_METHOD2_WITH_CALLTYPE(STDMETHODCALLTYPE, Bar, int(double x, double y)); | |||||
``` | |||||
where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows. | |||||
# Using Mocks in Tests # | |||||
The typical flow is: | |||||
1. Import the Google Mock names you need to use. All Google Mock names are in the `testing` namespace unless they are macros or otherwise noted. | |||||
1. Create the mock objects. | |||||
1. Optionally, set the default actions of the mock objects. | |||||
1. Set your expectations on the mock objects (How will they be called? What wil they do?). | |||||
1. Exercise code that uses the mock objects; if necessary, check the result using [Google Test](../../googletest/) assertions. | |||||
1. When a mock objects is destructed, Google Mock automatically verifies that all expectations on it have been satisfied. | |||||
Here is an example: | |||||
``` | |||||
using ::testing::Return; // #1 | |||||
TEST(BarTest, DoesThis) { | |||||
MockFoo foo; // #2 | |||||
ON_CALL(foo, GetSize()) // #3 | |||||
.WillByDefault(Return(1)); | |||||
// ... other default actions ... | |||||
EXPECT_CALL(foo, Describe(5)) // #4 | |||||
.Times(3) | |||||
.WillRepeatedly(Return("Category 5")); | |||||
// ... other expectations ... | |||||
EXPECT_EQ("good", MyProductionFunction(&foo)); // #5 | |||||
} // #6 | |||||
``` | |||||
# Setting Default Actions # | |||||
Google Mock has a **built-in default action** for any function that | |||||
returns `void`, `bool`, a numeric value, or a pointer. | |||||
To customize the default action for functions with return type `T` globally: | |||||
``` | |||||
using ::testing::DefaultValue; | |||||
// Sets the default value to be returned. T must be CopyConstructible. | |||||
DefaultValue<T>::Set(value); | |||||
// Sets a factory. Will be invoked on demand. T must be MoveConstructible. | |||||
// T MakeT(); | |||||
DefaultValue<T>::SetFactory(&MakeT); | |||||
// ... use the mocks ... | |||||
// Resets the default value. | |||||
DefaultValue<T>::Clear(); | |||||
``` | |||||
To customize the default action for a particular method, use `ON_CALL()`: | |||||
``` | |||||
ON_CALL(mock_object, method(matchers)) | |||||
.With(multi_argument_matcher) ? | |||||
.WillByDefault(action); | |||||
``` | |||||
# Setting Expectations # | |||||
`EXPECT_CALL()` sets **expectations** on a mock method (How will it be | |||||
called? What will it do?): | |||||
``` | |||||
EXPECT_CALL(mock_object, method(matchers)) | |||||
.With(multi_argument_matcher) ? | |||||
.Times(cardinality) ? | |||||
.InSequence(sequences) * | |||||
.After(expectations) * | |||||
.WillOnce(action) * | |||||
.WillRepeatedly(action) ? | |||||
.RetiresOnSaturation(); ? | |||||
``` | |||||
If `Times()` is omitted, the cardinality is assumed to be: | |||||
* `Times(1)` when there is neither `WillOnce()` nor `WillRepeatedly()`; | |||||
* `Times(n)` when there are `n WillOnce()`s but no `WillRepeatedly()`, where `n` >= 1; or | |||||
* `Times(AtLeast(n))` when there are `n WillOnce()`s and a `WillRepeatedly()`, where `n` >= 0. | |||||
A method with no `EXPECT_CALL()` is free to be invoked _any number of times_, and the default action will be taken each time. | |||||
# Matchers # | |||||
A **matcher** matches a _single_ argument. You can use it inside | |||||
`ON_CALL()` or `EXPECT_CALL()`, or use it to validate a value | |||||
directly: | |||||
| `EXPECT_THAT(value, matcher)` | Asserts that `value` matches `matcher`. | | |||||
|:------------------------------|:----------------------------------------| | |||||
| `ASSERT_THAT(value, matcher)` | The same as `EXPECT_THAT(value, matcher)`, except that it generates a **fatal** failure. | | |||||
Built-in matchers (where `argument` is the function argument) are | |||||
divided into several categories: | |||||
## Wildcard ## | |||||
|`_`|`argument` can be any value of the correct type.| | |||||
|:--|:-----------------------------------------------| | |||||
|`A<type>()` or `An<type>()`|`argument` can be any value of type `type`. | | |||||
## Generic Comparison ## | |||||
|`Eq(value)` or `value`|`argument == value`| | |||||
|:---------------------|:------------------| | |||||
|`Ge(value)` |`argument >= value`| | |||||
|`Gt(value)` |`argument > value` | | |||||
|`Le(value)` |`argument <= value`| | |||||
|`Lt(value)` |`argument < value` | | |||||
|`Ne(value)` |`argument != value`| | |||||
|`IsNull()` |`argument` is a `NULL` pointer (raw or smart).| | |||||
|`NotNull()` |`argument` is a non-null pointer (raw or smart).| | |||||
|`VariantWith<T>(m)` |`argument` is `variant<>` that holds the alternative of | |||||
type T with a value matching `m`.| | |||||
|`Ref(variable)` |`argument` is a reference to `variable`.| | |||||
|`TypedEq<type>(value)`|`argument` has type `type` and is equal to `value`. You may need to use this instead of `Eq(value)` when the mock function is overloaded.| | |||||
Except `Ref()`, these matchers make a _copy_ of `value` in case it's | |||||
modified or destructed later. If the compiler complains that `value` | |||||
doesn't have a public copy constructor, try wrap it in `ByRef()`, | |||||
e.g. `Eq(ByRef(non_copyable_value))`. If you do that, make sure | |||||
`non_copyable_value` is not changed afterwards, or the meaning of your | |||||
matcher will be changed. | |||||
## Floating-Point Matchers ## | |||||
|`DoubleEq(a_double)`|`argument` is a `double` value approximately equal to `a_double`, treating two NaNs as unequal.| | |||||
|:-------------------|:----------------------------------------------------------------------------------------------| | |||||
|`FloatEq(a_float)` |`argument` is a `float` value approximately equal to `a_float`, treating two NaNs as unequal. | | |||||
|`NanSensitiveDoubleEq(a_double)`|`argument` is a `double` value approximately equal to `a_double`, treating two NaNs as equal. | | |||||
|`NanSensitiveFloatEq(a_float)`|`argument` is a `float` value approximately equal to `a_float`, treating two NaNs as equal. | | |||||
The above matchers use ULP-based comparison (the same as used in | |||||
[Google Test](../../googletest/)). They | |||||
automatically pick a reasonable error bound based on the absolute | |||||
value of the expected value. `DoubleEq()` and `FloatEq()` conform to | |||||
the IEEE standard, which requires comparing two NaNs for equality to | |||||
return false. The `NanSensitive*` version instead treats two NaNs as | |||||
equal, which is often what a user wants. | |||||
|`DoubleNear(a_double, max_abs_error)`|`argument` is a `double` value close to `a_double` (absolute error <= `max_abs_error`), treating two NaNs as unequal.| | |||||
|:------------------------------------|:--------------------------------------------------------------------------------------------------------------------| | |||||
|`FloatNear(a_float, max_abs_error)` |`argument` is a `float` value close to `a_float` (absolute error <= `max_abs_error`), treating two NaNs as unequal. | | |||||
|`NanSensitiveDoubleNear(a_double, max_abs_error)`|`argument` is a `double` value close to `a_double` (absolute error <= `max_abs_error`), treating two NaNs as equal. | | |||||
|`NanSensitiveFloatNear(a_float, max_abs_error)`|`argument` is a `float` value close to `a_float` (absolute error <= `max_abs_error`), treating two NaNs as equal. | | |||||
## String Matchers ## | |||||
The `argument` can be either a C string or a C++ string object: | |||||
|`ContainsRegex(string)`|`argument` matches the given regular expression.| | |||||
|:----------------------|:-----------------------------------------------| | |||||
|`EndsWith(suffix)` |`argument` ends with string `suffix`. | | |||||
|`HasSubstr(string)` |`argument` contains `string` as a sub-string. | | |||||
|`MatchesRegex(string)` |`argument` matches the given regular expression with the match starting at the first character and ending at the last character.| | |||||
|`StartsWith(prefix)` |`argument` starts with string `prefix`. | | |||||
|`StrCaseEq(string)` |`argument` is equal to `string`, ignoring case. | | |||||
|`StrCaseNe(string)` |`argument` is not equal to `string`, ignoring case.| | |||||
|`StrEq(string)` |`argument` is equal to `string`. | | |||||
|`StrNe(string)` |`argument` is not equal to `string`. | | |||||
`ContainsRegex()` and `MatchesRegex()` use the regular expression | |||||
syntax defined | |||||
[here](../../googletest/docs/advanced.md#regular-expression-syntax). | |||||
`StrCaseEq()`, `StrCaseNe()`, `StrEq()`, and `StrNe()` work for wide | |||||
strings as well. | |||||
## Container Matchers ## | |||||
Most STL-style containers support `==`, so you can use | |||||
`Eq(expected_container)` or simply `expected_container` to match a | |||||
container exactly. If you want to write the elements in-line, | |||||
match them more flexibly, or get more informative messages, you can use: | |||||
| `ContainerEq(container)` | The same as `Eq(container)` except that the failure message also includes which elements are in one container but not the other. | | |||||
|:-------------------------|:---------------------------------------------------------------------------------------------------------------------------------| | |||||
| `Contains(e)` | `argument` contains an element that matches `e`, which can be either a value or a matcher. | | |||||
| `Each(e)` | `argument` is a container where _every_ element matches `e`, which can be either a value or a matcher. | | |||||
| `ElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, where the i-th element matches `ei`, which can be a value or a matcher. 0 to 10 arguments are allowed. | | |||||
| `ElementsAreArray({ e0, e1, ..., en })`, `ElementsAreArray(array)`, or `ElementsAreArray(array, count)` | The same as `ElementsAre()` except that the expected element values/matchers come from an initializer list, STL-style container, or C-style array. | | |||||
| `IsEmpty()` | `argument` is an empty container (`container.empty()`). | | |||||
| `Pointwise(m, container)` | `argument` contains the same number of elements as in `container`, and for all i, (the i-th element in `argument`, the i-th element in `container`) match `m`, which is a matcher on 2-tuples. E.g. `Pointwise(Le(), upper_bounds)` verifies that each element in `argument` doesn't exceed the corresponding element in `upper_bounds`. See more detail below. | | |||||
| `SizeIs(m)` | `argument` is a container whose size matches `m`. E.g. `SizeIs(2)` or `SizeIs(Lt(2))`. | | |||||
| `UnorderedElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, and under some permutation each element matches an `ei` (for a different `i`), which can be a value or a matcher. 0 to 10 arguments are allowed. | | |||||
| `UnorderedElementsAreArray({ e0, e1, ..., en })`, `UnorderedElementsAreArray(array)`, or `UnorderedElementsAreArray(array, count)` | The same as `UnorderedElementsAre()` except that the expected element values/matchers come from an initializer list, STL-style container, or C-style array. | | |||||
| `WhenSorted(m)` | When `argument` is sorted using the `<` operator, it matches container matcher `m`. E.g. `WhenSorted(ElementsAre(1, 2, 3))` verifies that `argument` contains elements `1`, `2`, and `3`, ignoring order. | | |||||
| `WhenSortedBy(comparator, m)` | The same as `WhenSorted(m)`, except that the given comparator instead of `<` is used to sort `argument`. E.g. `WhenSortedBy(std::greater<int>(), ElementsAre(3, 2, 1))`. | | |||||
Notes: | |||||
* These matchers can also match: | |||||
1. a native array passed by reference (e.g. in `Foo(const int (&a)[5])`), and | |||||
1. an array passed as a pointer and a count (e.g. in `Bar(const T* buffer, int len)` -- see [Multi-argument Matchers](#Multiargument_Matchers.md)). | |||||
* The array being matched may be multi-dimensional (i.e. its elements can be arrays). | |||||
* `m` in `Pointwise(m, ...)` should be a matcher for `::testing::tuple<T, U>` where `T` and `U` are the element type of the actual container and the expected container, respectively. For example, to compare two `Foo` containers where `Foo` doesn't support `operator==` but has an `Equals()` method, one might write: | |||||
``` | |||||
using ::testing::get; | |||||
MATCHER(FooEq, "") { | |||||
return get<0>(arg).Equals(get<1>(arg)); | |||||
} | |||||
... | |||||
EXPECT_THAT(actual_foos, Pointwise(FooEq(), expected_foos)); | |||||
``` | |||||
## Member Matchers ## | |||||
|`Field(&class::field, m)`|`argument.field` (or `argument->field` when `argument` is a plain pointer) matches matcher `m`, where `argument` is an object of type _class_.| | |||||
|:------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------| | |||||
|`Key(e)` |`argument.first` matches `e`, which can be either a value or a matcher. E.g. `Contains(Key(Le(5)))` can verify that a `map` contains a key `<= 5`.| | |||||
|`Pair(m1, m2)` |`argument` is an `std::pair` whose `first` field matches `m1` and `second` field matches `m2`. | | |||||
|`Property(&class::property, m)`|`argument.property()` (or `argument->property()` when `argument` is a plain pointer) matches matcher `m`, where `argument` is an object of type _class_.| | |||||
## Matching the Result of a Function or Functor ## | |||||
|`ResultOf(f, m)`|`f(argument)` matches matcher `m`, where `f` is a function or functor.| | |||||
|:---------------|:---------------------------------------------------------------------| | |||||
## Pointer Matchers ## | |||||
|`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`. | | |||||
## Multiargument Matchers ## | |||||
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)`: | |||||
|`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: | |||||
|`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: | |||||
|`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 ## | |||||
|`MatcherCast<T>(m)`|casts matcher `m` to type `Matcher<T>`.| | |||||
|:------------------|:--------------------------------------| | |||||
|`SafeMatcherCast<T>(m)`| [safely casts](CookBook.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.| | |||||
## Matchers as Predicates ## | |||||
|`Matches(m)(value)`|evaluates to `true` if `value` matches `m`. You can use `Matches(m)` alone as a unary functor.| | |||||
|:------------------|:---------------------------------------------------------------------------------------------| | |||||
|`ExplainMatchResult(m, value, result_listener)`|evaluates to `true` if `value` matches `m`, explaining the result to `result_listener`. | | |||||
|`Value(value, m)` |evaluates to `true` if `value` matches `m`. | | |||||
## Defining Matchers ## | |||||
| `MATCHER(IsEven, "") { return (arg % 2) == 0; }` | Defines a matcher `IsEven()` to match an even number. | | |||||
|:-------------------------------------------------|:------------------------------------------------------| | |||||
| `MATCHER_P(IsDivisibleBy, n, "") { *result_listener << "where the remainder is " << (arg % n); return (arg % n) == 0; }` | Defines a macher `IsDivisibleBy(n)` to match a number divisible by `n`. | | |||||
| `MATCHER_P2(IsBetween, a, b, std::string(negation ? "isn't" : "is") + " between " + PrintToString(a) + " and " + PrintToString(b)) { return a <= arg && arg <= b; }` | Defines a matcher `IsBetween(a, b)` to match a value in the range [`a`, `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 ## | |||||
|`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 # | |||||
**Actions** specify what a mock function should do when invoked. | |||||
## Returning a Value ## | |||||
|`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 ## | |||||
|`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 or a Functor as an Action ## | |||||
|`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, &class::method)`|Invoke the {method on the object with 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, &class::method)`|Invoke the method on the object, which takes no arguments. | | |||||
|`InvokeArgument<N>(arg1, arg2, ..., argk)`|Invoke the mock function's `N`-th (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 function or functor to be used with `Invoke*()`, you can declare any unused parameters as `Unused`: | |||||
``` | |||||
double Distance(Unused, double x, double y) { return sqrt(x*x + y*y); } | |||||
... | |||||
EXPECT_CALL(mock, Foo("Hi", _, _)).WillOnce(Invoke(Distance)); | |||||
``` | |||||
In `InvokeArgument<N>(...)`, if an argument needs to be passed by reference, wrap it inside `ByRef()`. For example, | |||||
``` | |||||
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 ## | |||||
|`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 ## | |||||
|`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 ## | |||||
| `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 + n; }` | Defines an action `Plus(n)` to return the sum of the mock function's argument #0 and `n`. | | |||||
| `ACTION_Pk(Foo, p1, ..., pk) { statements; }` | Defines a parameterized action `Foo(p1, ..., pk)` to execute the given `statements`. | | |||||
The `ACTION*` macros cannot be used inside a function or class. | |||||
# Cardinalities # | |||||
These are used in `Times()` to specify how many times a mock function will be called: | |||||
|`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 ## | |||||
``` | |||||
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: | |||||
``` | |||||
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 ## | |||||
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. <i>All expected<br> | |||||
calls</i> in the same sequence must occur in the order they are | |||||
specified. | |||||
``` | |||||
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: | |||||
``` | |||||
using ::testing::InSequence; | |||||
{ | |||||
InSequence dummy; | |||||
EXPECT_CALL(...)...; | |||||
EXPECT_CALL(...)...; | |||||
... | |||||
EXPECT_CALL(...)...; | |||||
} | |||||
``` | |||||
says that all expected calls in the scope of `dummy` must occur in | |||||
strict order. The name `dummy` is irrelevant.) | |||||
# Verifying and Resetting a Mock # | |||||
Google Mock will verify the expectations on a mock object when it is destructed, or you can do it earlier: | |||||
``` | |||||
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 Google Mock that a mock object can be leaked and doesn't | |||||
need to be verified: | |||||
``` | |||||
Mock::AllowLeak(&mock_obj); | |||||
``` | |||||
# Mock Classes # | |||||
Google Mock defines a convenient mock class template | |||||
``` | |||||
class MockFunction<R(A1, ..., An)> { | |||||
public: | |||||
MOCK_METHODn(Call, R(A1, ..., An)); | |||||
}; | |||||
``` | |||||
See this [recipe](CookBook.md#using-check-points) for one application of it. | |||||
# Flags # | |||||
| `--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. | |