1 2 3# Defining a Mock Class # 4 5## Mocking a Normal Class ## 6 7Given 8``` 9class Foo { 10 ... 11 virtual ~Foo(); 12 virtual int GetSize() const = 0; 13 virtual string Describe(const char* name) = 0; 14 virtual string Describe(int type) = 0; 15 virtual bool Process(Bar elem, int count) = 0; 16}; 17``` 18(note that `~Foo()` **must** be virtual) we can define its mock as 19``` 20#include "gmock/gmock.h" 21 22class MockFoo : public Foo { 23 MOCK_CONST_METHOD0(GetSize, int()); 24 MOCK_METHOD1(Describe, string(const char* name)); 25 MOCK_METHOD1(Describe, string(int type)); 26 MOCK_METHOD2(Process, bool(Bar elem, int count)); 27}; 28``` 29 30To create a "nice" mock object which ignores all uninteresting calls, 31or a "strict" mock object, which treats them as failures: 32``` 33NiceMock<MockFoo> nice_foo; // The type is a subclass of MockFoo. 34StrictMock<MockFoo> strict_foo; // The type is a subclass of MockFoo. 35``` 36 37## Mocking a Class Template ## 38 39To mock 40``` 41template <typename Elem> 42class StackInterface { 43 public: 44 ... 45 virtual ~StackInterface(); 46 virtual int GetSize() const = 0; 47 virtual void Push(const Elem& x) = 0; 48}; 49``` 50(note that `~StackInterface()` **must** be virtual) just append `_T` to the `MOCK_*` macros: 51``` 52template <typename Elem> 53class MockStack : public StackInterface<Elem> { 54 public: 55 ... 56 MOCK_CONST_METHOD0_T(GetSize, int()); 57 MOCK_METHOD1_T(Push, void(const Elem& x)); 58}; 59``` 60 61## Specifying Calling Conventions for Mock Functions ## 62 63If your mock function doesn't use the default calling convention, you 64can specify it by appending `_WITH_CALLTYPE` to any of the macros 65described in the previous two sections and supplying the calling 66convention as the first argument to the macro. For example, 67``` 68 MOCK_METHOD1_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int n)); 69 MOCK_CONST_METHOD2_WITH_CALLTYPE(STDMETHODCALLTYPE, Bar, int(double x, double y)); 70``` 71where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows. 72 73# Using Mocks in Tests # 74 75The typical flow is: 76 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. 77 1. Create the mock objects. 78 1. Optionally, set the default actions of the mock objects. 79 1. Set your expectations on the mock objects (How will they be called? What wil they do?). 80 1. Exercise code that uses the mock objects; if necessary, check the result using [Google Test](../../googletest/) assertions. 81 1. When a mock objects is destructed, Google Mock automatically verifies that all expectations on it have been satisfied. 82 83Here is an example: 84``` 85using ::testing::Return; // #1 86 87TEST(BarTest, DoesThis) { 88 MockFoo foo; // #2 89 90 ON_CALL(foo, GetSize()) // #3 91 .WillByDefault(Return(1)); 92 // ... other default actions ... 93 94 EXPECT_CALL(foo, Describe(5)) // #4 95 .Times(3) 96 .WillRepeatedly(Return("Category 5")); 97 // ... other expectations ... 98 99 EXPECT_EQ("good", MyProductionFunction(&foo)); // #5 100} // #6 101``` 102 103# Setting Default Actions # 104 105Google Mock has a **built-in default action** for any function that 106returns `void`, `bool`, a numeric value, or a pointer. 107 108To customize the default action for functions with return type `T` globally: 109``` 110using ::testing::DefaultValue; 111 112// Sets the default value to be returned. T must be CopyConstructible. 113DefaultValue<T>::Set(value); 114// Sets a factory. Will be invoked on demand. T must be MoveConstructible. 115// T MakeT(); 116DefaultValue<T>::SetFactory(&MakeT); 117// ... use the mocks ... 118// Resets the default value. 119DefaultValue<T>::Clear(); 120``` 121 122To customize the default action for a particular method, use `ON_CALL()`: 123``` 124ON_CALL(mock_object, method(matchers)) 125 .With(multi_argument_matcher) ? 126 .WillByDefault(action); 127``` 128 129# Setting Expectations # 130 131`EXPECT_CALL()` sets **expectations** on a mock method (How will it be 132called? What will it do?): 133``` 134EXPECT_CALL(mock_object, method(matchers)) 135 .With(multi_argument_matcher) ? 136 .Times(cardinality) ? 137 .InSequence(sequences) * 138 .After(expectations) * 139 .WillOnce(action) * 140 .WillRepeatedly(action) ? 141 .RetiresOnSaturation(); ? 142``` 143 144If `Times()` is omitted, the cardinality is assumed to be: 145 146 * `Times(1)` when there is neither `WillOnce()` nor `WillRepeatedly()`; 147 * `Times(n)` when there are `n WillOnce()`s but no `WillRepeatedly()`, where `n` >= 1; or 148 * `Times(AtLeast(n))` when there are `n WillOnce()`s and a `WillRepeatedly()`, where `n` >= 0. 149 150A method with no `EXPECT_CALL()` is free to be invoked _any number of times_, and the default action will be taken each time. 151 152# Matchers # 153 154A **matcher** matches a _single_ argument. You can use it inside 155`ON_CALL()` or `EXPECT_CALL()`, or use it to validate a value 156directly: 157 158| `EXPECT_THAT(value, matcher)` | Asserts that `value` matches `matcher`. | 159|:------------------------------|:----------------------------------------| 160| `ASSERT_THAT(value, matcher)` | The same as `EXPECT_THAT(value, matcher)`, except that it generates a **fatal** failure. | 161 162Built-in matchers (where `argument` is the function argument) are 163divided into several categories: 164 165## Wildcard ## 166|`_`|`argument` can be any value of the correct type.| 167|:--|:-----------------------------------------------| 168|`A<type>()` or `An<type>()`|`argument` can be any value of type `type`. | 169 170## Generic Comparison ## 171 172|`Eq(value)` or `value`|`argument == value`| 173|:---------------------|:------------------| 174|`Ge(value)` |`argument >= value`| 175|`Gt(value)` |`argument > value` | 176|`Le(value)` |`argument <= value`| 177|`Lt(value)` |`argument < value` | 178|`Ne(value)` |`argument != value`| 179|`IsNull()` |`argument` is a `NULL` pointer (raw or smart).| 180|`NotNull()` |`argument` is a non-null pointer (raw or smart).| 181|`VariantWith<T>(m)` |`argument` is `variant<>` that holds the alternative of 182type T with a value matching `m`.| 183|`Ref(variable)` |`argument` is a reference to `variable`.| 184|`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.| 185 186Except `Ref()`, these matchers make a _copy_ of `value` in case it's 187modified or destructed later. If the compiler complains that `value` 188doesn't have a public copy constructor, try wrap it in `ByRef()`, 189e.g. `Eq(ByRef(non_copyable_value))`. If you do that, make sure 190`non_copyable_value` is not changed afterwards, or the meaning of your 191matcher will be changed. 192 193## Floating-Point Matchers ## 194 195|`DoubleEq(a_double)`|`argument` is a `double` value approximately equal to `a_double`, treating two NaNs as unequal.| 196|:-------------------|:----------------------------------------------------------------------------------------------| 197|`FloatEq(a_float)` |`argument` is a `float` value approximately equal to `a_float`, treating two NaNs as unequal. | 198|`NanSensitiveDoubleEq(a_double)`|`argument` is a `double` value approximately equal to `a_double`, treating two NaNs as equal. | 199|`NanSensitiveFloatEq(a_float)`|`argument` is a `float` value approximately equal to `a_float`, treating two NaNs as equal. | 200 201The above matchers use ULP-based comparison (the same as used in 202[Google Test](../../googletest/)). They 203automatically pick a reasonable error bound based on the absolute 204value of the expected value. `DoubleEq()` and `FloatEq()` conform to 205the IEEE standard, which requires comparing two NaNs for equality to 206return false. The `NanSensitive*` version instead treats two NaNs as 207equal, which is often what a user wants. 208 209|`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.| 210|:------------------------------------|:--------------------------------------------------------------------------------------------------------------------| 211|`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. | 212|`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. | 213|`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. | 214 215## String Matchers ## 216 217The `argument` can be either a C string or a C++ string object: 218 219|`ContainsRegex(string)`|`argument` matches the given regular expression.| 220|:----------------------|:-----------------------------------------------| 221|`EndsWith(suffix)` |`argument` ends with string `suffix`. | 222|`HasSubstr(string)` |`argument` contains `string` as a sub-string. | 223|`MatchesRegex(string)` |`argument` matches the given regular expression with the match starting at the first character and ending at the last character.| 224|`StartsWith(prefix)` |`argument` starts with string `prefix`. | 225|`StrCaseEq(string)` |`argument` is equal to `string`, ignoring case. | 226|`StrCaseNe(string)` |`argument` is not equal to `string`, ignoring case.| 227|`StrEq(string)` |`argument` is equal to `string`. | 228|`StrNe(string)` |`argument` is not equal to `string`. | 229 230`ContainsRegex()` and `MatchesRegex()` use the regular expression 231syntax defined 232[here](../../googletest/docs/advanced.md#regular-expression-syntax). 233`StrCaseEq()`, `StrCaseNe()`, `StrEq()`, and `StrNe()` work for wide 234strings as well. 235 236## Container Matchers ## 237 238Most STL-style containers support `==`, so you can use 239`Eq(expected_container)` or simply `expected_container` to match a 240container exactly. If you want to write the elements in-line, 241match them more flexibly, or get more informative messages, you can use: 242 243| `ContainerEq(container)` | The same as `Eq(container)` except that the failure message also includes which elements are in one container but not the other. | 244|:-------------------------|:---------------------------------------------------------------------------------------------------------------------------------| 245| `Contains(e)` | `argument` contains an element that matches `e`, which can be either a value or a matcher. | 246| `Each(e)` | `argument` is a container where _every_ element matches `e`, which can be either a value or a matcher. | 247| `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. | 248| `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. | 249| `IsEmpty()` | `argument` is an empty container (`container.empty()`). | 250| `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. | 251| `SizeIs(m)` | `argument` is a container whose size matches `m`. E.g. `SizeIs(2)` or `SizeIs(Lt(2))`. | 252| `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. | 253| `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. | 254| `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. | 255| `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))`. | 256 257Notes: 258 259 * These matchers can also match: 260 1. a native array passed by reference (e.g. in `Foo(const int (&a)[5])`), and 261 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)). 262 * The array being matched may be multi-dimensional (i.e. its elements can be arrays). 263 * `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: 264 265``` 266using ::testing::get; 267MATCHER(FooEq, "") { 268 return get<0>(arg).Equals(get<1>(arg)); 269} 270... 271EXPECT_THAT(actual_foos, Pointwise(FooEq(), expected_foos)); 272``` 273 274## Member Matchers ## 275 276|`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_.| 277|:------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------| 278|`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`.| 279|`Pair(m1, m2)` |`argument` is an `std::pair` whose `first` field matches `m1` and `second` field matches `m2`. | 280|`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_.| 281 282## Matching the Result of a Function or Functor ## 283 284|`ResultOf(f, m)`|`f(argument)` matches matcher `m`, where `f` is a function or functor.| 285|:---------------|:---------------------------------------------------------------------| 286 287## Pointer Matchers ## 288 289|`Pointee(m)`|`argument` (either a smart pointer or a raw pointer) points to a value that matches matcher `m`.| 290|:-----------|:-----------------------------------------------------------------------------------------------| 291|`WhenDynamicCastTo<T>(m)`| when `argument` is passed through `dynamic_cast<T>()`, it matches matcher `m`. | 292 293## Multiargument Matchers ## 294 295Technically, all matchers match a _single_ value. A "multi-argument" 296matcher is just one that matches a _tuple_. The following matchers can 297be used to match a tuple `(x, y)`: 298 299|`Eq()`|`x == y`| 300|:-----|:-------| 301|`Ge()`|`x >= y`| 302|`Gt()`|`x > y` | 303|`Le()`|`x <= y`| 304|`Lt()`|`x < y` | 305|`Ne()`|`x != y`| 306 307You can use the following selectors to pick a subset of the arguments 308(or reorder them) to participate in the matching: 309 310|`AllArgs(m)`|Equivalent to `m`. Useful as syntactic sugar in `.With(AllArgs(m))`.| 311|:-----------|:-------------------------------------------------------------------| 312|`Args<N1, N2, ..., Nk>(m)`|The tuple of the `k` selected (using 0-based indices) arguments matches `m`, e.g. `Args<1, 2>(Eq())`.| 313 314## Composite Matchers ## 315 316You can make a matcher from one or more other matchers: 317 318|`AllOf(m1, m2, ..., mn)`|`argument` matches all of the matchers `m1` to `mn`.| 319|:-----------------------|:---------------------------------------------------| 320|`AnyOf(m1, m2, ..., mn)`|`argument` matches at least one of the matchers `m1` to `mn`.| 321|`Not(m)` |`argument` doesn't match matcher `m`. | 322 323## Adapters for Matchers ## 324 325|`MatcherCast<T>(m)`|casts matcher `m` to type `Matcher<T>`.| 326|:------------------|:--------------------------------------| 327|`SafeMatcherCast<T>(m)`| [safely casts](CookBook.md#casting-matchers) matcher `m` to type `Matcher<T>`. | 328|`Truly(predicate)` |`predicate(argument)` returns something considered by C++ to be true, where `predicate` is a function or functor.| 329 330## Matchers as Predicates ## 331 332|`Matches(m)(value)`|evaluates to `true` if `value` matches `m`. You can use `Matches(m)` alone as a unary functor.| 333|:------------------|:---------------------------------------------------------------------------------------------| 334|`ExplainMatchResult(m, value, result_listener)`|evaluates to `true` if `value` matches `m`, explaining the result to `result_listener`. | 335|`Value(value, m)` |evaluates to `true` if `value` matches `m`. | 336 337## Defining Matchers ## 338 339| `MATCHER(IsEven, "") { return (arg % 2) == 0; }` | Defines a matcher `IsEven()` to match an even number. | 340|:-------------------------------------------------|:------------------------------------------------------| 341| `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`. | 342| `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`]. | 343 344**Notes:** 345 346 1. The `MATCHER*` macros cannot be used inside a function or class. 347 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). 348 1. You can use `PrintToString(x)` to convert a value `x` of any type to a string. 349 350## Matchers as Test Assertions ## 351 352|`ASSERT_THAT(expression, m)`|Generates a [fatal failure](../../googletest/docs/primer.md#assertions) if the value of `expression` doesn't match matcher `m`.| 353|:---------------------------|:----------------------------------------------------------------------------------------------------------------------------------------------| 354|`EXPECT_THAT(expression, m)`|Generates a non-fatal failure if the value of `expression` doesn't match matcher `m`. | 355 356# Actions # 357 358**Actions** specify what a mock function should do when invoked. 359 360## Returning a Value ## 361 362|`Return()`|Return from a `void` mock function.| 363|:---------|:----------------------------------| 364|`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.| 365|`ReturnArg<N>()`|Return the `N`-th (0-based) argument.| 366|`ReturnNew<T>(a1, ..., ak)`|Return `new T(a1, ..., ak)`; a different object is created each time.| 367|`ReturnNull()`|Return a null pointer. | 368|`ReturnPointee(ptr)`|Return the value pointed to by `ptr`.| 369|`ReturnRef(variable)`|Return a reference to `variable`. | 370|`ReturnRefOfCopy(value)`|Return a reference to a copy of `value`; the copy lives as long as the action.| 371 372## Side Effects ## 373 374|`Assign(&variable, value)`|Assign `value` to variable.| 375|:-------------------------|:--------------------------| 376| `DeleteArg<N>()` | Delete the `N`-th (0-based) argument, which must be a pointer. | 377| `SaveArg<N>(pointer)` | Save the `N`-th (0-based) argument to `*pointer`. | 378| `SaveArgPointee<N>(pointer)` | Save the value pointed to by the `N`-th (0-based) argument to `*pointer`. | 379| `SetArgReferee<N>(value)` | Assign value to the variable referenced by the `N`-th (0-based) argument. | 380|`SetArgPointee<N>(value)` |Assign `value` to the variable pointed by the `N`-th (0-based) argument.| 381|`SetArgumentPointee<N>(value)`|Same as `SetArgPointee<N>(value)`. Deprecated. Will be removed in v1.7.0.| 382|`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.| 383|`SetErrnoAndReturn(error, value)`|Set `errno` to `error` and return `value`.| 384|`Throw(exception)` |Throws the given exception, which can be any copyable value. Available since v1.1.0.| 385 386## Using a Function or a Functor as an Action ## 387 388|`Invoke(f)`|Invoke `f` with the arguments passed to the mock function, where `f` can be a global/static function or a functor.| 389|:----------|:-----------------------------------------------------------------------------------------------------------------| 390|`Invoke(object_pointer, &class::method)`|Invoke the {method on the object with the arguments passed to the mock function. | 391|`InvokeWithoutArgs(f)`|Invoke `f`, which can be a global/static function or a functor. `f` must take no arguments. | 392|`InvokeWithoutArgs(object_pointer, &class::method)`|Invoke the method on the object, which takes no arguments. | 393|`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.| 394 395The return value of the invoked function is used as the return value 396of the action. 397 398When defining a function or functor to be used with `Invoke*()`, you can declare any unused parameters as `Unused`: 399``` 400 double Distance(Unused, double x, double y) { return sqrt(x*x + y*y); } 401 ... 402 EXPECT_CALL(mock, Foo("Hi", _, _)).WillOnce(Invoke(Distance)); 403``` 404 405In `InvokeArgument<N>(...)`, if an argument needs to be passed by reference, wrap it inside `ByRef()`. For example, 406``` 407 InvokeArgument<2>(5, string("Hi"), ByRef(foo)) 408``` 409calls the mock function's #2 argument, passing to it `5` and `string("Hi")` by value, and `foo` by reference. 410 411## Default Action ## 412 413|`DoDefault()`|Do the default action (specified by `ON_CALL()` or the built-in one).| 414|:------------|:--------------------------------------------------------------------| 415 416**Note:** due to technical reasons, `DoDefault()` cannot be used inside a composite action - trying to do so will result in a run-time error. 417 418## Composite Actions ## 419 420|`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. | 421|:-----------------------|:-----------------------------------------------------------------------------------------------------------------------------| 422|`IgnoreResult(a)` |Perform action `a` and ignore its result. `a` must not return void. | 423|`WithArg<N>(a)` |Pass the `N`-th (0-based) argument of the mock function to action `a` and perform it. | 424|`WithArgs<N1, N2, ..., Nk>(a)`|Pass the selected (0-based) arguments of the mock function to action `a` and perform it. | 425|`WithoutArgs(a)` |Perform action `a` without any arguments. | 426 427## Defining Actions ## 428 429| `ACTION(Sum) { return arg0 + arg1; }` | Defines an action `Sum()` to return the sum of the mock function's argument #0 and #1. | 430|:--------------------------------------|:---------------------------------------------------------------------------------------| 431| `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`. | 432| `ACTION_Pk(Foo, p1, ..., pk) { statements; }` | Defines a parameterized action `Foo(p1, ..., pk)` to execute the given `statements`. | 433 434The `ACTION*` macros cannot be used inside a function or class. 435 436# Cardinalities # 437 438These are used in `Times()` to specify how many times a mock function will be called: 439 440|`AnyNumber()`|The function can be called any number of times.| 441|:------------|:----------------------------------------------| 442|`AtLeast(n)` |The call is expected at least `n` times. | 443|`AtMost(n)` |The call is expected at most `n` times. | 444|`Between(m, n)`|The call is expected between `m` and `n` (inclusive) times.| 445|`Exactly(n) or n`|The call is expected exactly `n` times. In particular, the call should never happen when `n` is 0.| 446 447# Expectation Order # 448 449By default, the expectations can be matched in _any_ order. If some 450or all expectations must be matched in a given order, there are two 451ways to specify it. They can be used either independently or 452together. 453 454## The After Clause ## 455 456``` 457using ::testing::Expectation; 458... 459Expectation init_x = EXPECT_CALL(foo, InitX()); 460Expectation init_y = EXPECT_CALL(foo, InitY()); 461EXPECT_CALL(foo, Bar()) 462 .After(init_x, init_y); 463``` 464says that `Bar()` can be called only after both `InitX()` and 465`InitY()` have been called. 466 467If you don't know how many pre-requisites an expectation has when you 468write it, you can use an `ExpectationSet` to collect them: 469 470``` 471using ::testing::ExpectationSet; 472... 473ExpectationSet all_inits; 474for (int i = 0; i < element_count; i++) { 475 all_inits += EXPECT_CALL(foo, InitElement(i)); 476} 477EXPECT_CALL(foo, Bar()) 478 .After(all_inits); 479``` 480says that `Bar()` can be called only after all elements have been 481initialized (but we don't care about which elements get initialized 482before the others). 483 484Modifying an `ExpectationSet` after using it in an `.After()` doesn't 485affect the meaning of the `.After()`. 486 487## Sequences ## 488 489When you have a long chain of sequential expectations, it's easier to 490specify the order using **sequences**, which don't require you to given 491each expectation in the chain a different name. <i>All expected<br> 492calls</i> in the same sequence must occur in the order they are 493specified. 494 495``` 496using ::testing::Sequence; 497Sequence s1, s2; 498... 499EXPECT_CALL(foo, Reset()) 500 .InSequence(s1, s2) 501 .WillOnce(Return(true)); 502EXPECT_CALL(foo, GetSize()) 503 .InSequence(s1) 504 .WillOnce(Return(1)); 505EXPECT_CALL(foo, Describe(A<const char*>())) 506 .InSequence(s2) 507 .WillOnce(Return("dummy")); 508``` 509says that `Reset()` must be called before _both_ `GetSize()` _and_ 510`Describe()`, and the latter two can occur in any order. 511 512To put many expectations in a sequence conveniently: 513``` 514using ::testing::InSequence; 515{ 516 InSequence dummy; 517 518 EXPECT_CALL(...)...; 519 EXPECT_CALL(...)...; 520 ... 521 EXPECT_CALL(...)...; 522} 523``` 524says that all expected calls in the scope of `dummy` must occur in 525strict order. The name `dummy` is irrelevant.) 526 527# Verifying and Resetting a Mock # 528 529Google Mock will verify the expectations on a mock object when it is destructed, or you can do it earlier: 530``` 531using ::testing::Mock; 532... 533// Verifies and removes the expectations on mock_obj; 534// returns true iff successful. 535Mock::VerifyAndClearExpectations(&mock_obj); 536... 537// Verifies and removes the expectations on mock_obj; 538// also removes the default actions set by ON_CALL(); 539// returns true iff successful. 540Mock::VerifyAndClear(&mock_obj); 541``` 542 543You can also tell Google Mock that a mock object can be leaked and doesn't 544need to be verified: 545``` 546Mock::AllowLeak(&mock_obj); 547``` 548 549# Mock Classes # 550 551Google Mock defines a convenient mock class template 552``` 553class MockFunction<R(A1, ..., An)> { 554 public: 555 MOCK_METHODn(Call, R(A1, ..., An)); 556}; 557``` 558See this [recipe](CookBook.md#using-check-points) for one application of it. 559 560# Flags # 561 562| `--gmock_catch_leaked_mocks=0` | Don't report leaked mock objects as failures. | 563|:-------------------------------|:----------------------------------------------| 564| `--gmock_verbose=LEVEL` | Sets the default verbosity level (`info`, `warning`, or `error`) of Google Mock messages. | 565