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0001 
0002 
0003 # Defining a Mock Class #
0004 
0005 ## Mocking a Normal Class ##
0006 
0007 Given
0008 ```
0009 class Foo {
0010   ...
0011   virtual ~Foo();
0012   virtual int GetSize() const = 0;
0013   virtual string Describe(const char* name) = 0;
0014   virtual string Describe(int type) = 0;
0015   virtual bool Process(Bar elem, int count) = 0;
0016 };
0017 ```
0018 (note that `~Foo()` **must** be virtual) we can define its mock as
0019 ```
0020 #include "gmock/gmock.h"
0021 
0022 class MockFoo : public Foo {
0023   MOCK_CONST_METHOD0(GetSize, int());
0024   MOCK_METHOD1(Describe, string(const char* name));
0025   MOCK_METHOD1(Describe, string(int type));
0026   MOCK_METHOD2(Process, bool(Bar elem, int count));
0027 };
0028 ```
0029 
0030 To create a "nice" mock object which ignores all uninteresting calls,
0031 or a "strict" mock object, which treats them as failures:
0032 ```
0033 NiceMock<MockFoo> nice_foo;     // The type is a subclass of MockFoo.
0034 StrictMock<MockFoo> strict_foo; // The type is a subclass of MockFoo.
0035 ```
0036 
0037 ## Mocking a Class Template ##
0038 
0039 To mock
0040 ```
0041 template <typename Elem>
0042 class StackInterface {
0043  public:
0044   ...
0045   virtual ~StackInterface();
0046   virtual int GetSize() const = 0;
0047   virtual void Push(const Elem& x) = 0;
0048 };
0049 ```
0050 (note that `~StackInterface()` **must** be virtual) just append `_T` to the `MOCK_*` macros:
0051 ```
0052 template <typename Elem>
0053 class MockStack : public StackInterface<Elem> {
0054  public:
0055   ...
0056   MOCK_CONST_METHOD0_T(GetSize, int());
0057   MOCK_METHOD1_T(Push, void(const Elem& x));
0058 };
0059 ```
0060 
0061 ## Specifying Calling Conventions for Mock Functions ##
0062 
0063 If your mock function doesn't use the default calling convention, you
0064 can specify it by appending `_WITH_CALLTYPE` to any of the macros
0065 described in the previous two sections and supplying the calling
0066 convention as the first argument to the macro. For example,
0067 ```
0068   MOCK_METHOD_1_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int n));
0069   MOCK_CONST_METHOD2_WITH_CALLTYPE(STDMETHODCALLTYPE, Bar, int(double x, double y));
0070 ```
0071 where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows.
0072 
0073 # Using Mocks in Tests #
0074 
0075 The typical flow is:
0076   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.
0077   1. Create the mock objects.
0078   1. Optionally, set the default actions of the mock objects.
0079   1. Set your expectations on the mock objects (How will they be called? What wil they do?).
0080   1. Exercise code that uses the mock objects; if necessary, check the result using [Google Test](http://code.google.com/p/googletest/) assertions.
0081   1. When a mock objects is destructed, Google Mock automatically verifies that all expectations on it have been satisfied.
0082 
0083 Here is an example:
0084 ```
0085 using ::testing::Return;                            // #1
0086 
0087 TEST(BarTest, DoesThis) {
0088   MockFoo foo;                                    // #2
0089 
0090   ON_CALL(foo, GetSize())                         // #3
0091       .WillByDefault(Return(1));
0092   // ... other default actions ...
0093 
0094   EXPECT_CALL(foo, Describe(5))                   // #4
0095       .Times(3)
0096       .WillRepeatedly(Return("Category 5"));
0097   // ... other expectations ...
0098 
0099   EXPECT_EQ("good", MyProductionFunction(&foo));  // #5
0100 }                                                 // #6
0101 ```
0102 
0103 # Setting Default Actions #
0104 
0105 Google Mock has a **built-in default action** for any function that
0106 returns `void`, `bool`, a numeric value, or a pointer.
0107 
0108 To customize the default action for functions with return type `T` globally:
0109 ```
0110 using ::testing::DefaultValue;
0111 
0112 DefaultValue<T>::Set(value);  // Sets the default value to be returned.
0113 // ... use the mocks ...
0114 DefaultValue<T>::Clear();     // Resets the default value.
0115 ```
0116 
0117 To customize the default action for a particular method, use `ON_CALL()`:
0118 ```
0119 ON_CALL(mock_object, method(matchers))
0120     .With(multi_argument_matcher)  ?
0121     .WillByDefault(action);
0122 ```
0123 
0124 # Setting Expectations #
0125 
0126 `EXPECT_CALL()` sets **expectations** on a mock method (How will it be
0127 called? What will it do?):
0128 ```
0129 EXPECT_CALL(mock_object, method(matchers))
0130     .With(multi_argument_matcher)  ?
0131     .Times(cardinality)            ?
0132     .InSequence(sequences)         *
0133     .After(expectations)           *
0134     .WillOnce(action)              *
0135     .WillRepeatedly(action)        ?
0136     .RetiresOnSaturation();        ?
0137 ```
0138 
0139 If `Times()` is omitted, the cardinality is assumed to be:
0140 
0141   * `Times(1)` when there is neither `WillOnce()` nor `WillRepeatedly()`;
0142   * `Times(n)` when there are `n WillOnce()`s but no `WillRepeatedly()`, where `n` >= 1; or
0143   * `Times(AtLeast(n))` when there are `n WillOnce()`s and a `WillRepeatedly()`, where `n` >= 0.
0144 
0145 A method with no `EXPECT_CALL()` is free to be invoked _any number of times_, and the default action will be taken each time.
0146 
0147 # Matchers #
0148 
0149 A **matcher** matches a _single_ argument.  You can use it inside
0150 `ON_CALL()` or `EXPECT_CALL()`, or use it to validate a value
0151 directly:
0152 
0153 | `EXPECT_THAT(value, matcher)` | Asserts that `value` matches `matcher`. |
0154 |:------------------------------|:----------------------------------------|
0155 | `ASSERT_THAT(value, matcher)` | The same as `EXPECT_THAT(value, matcher)`, except that it generates a **fatal** failure. |
0156 
0157 Built-in matchers (where `argument` is the function argument) are
0158 divided into several categories:
0159 
0160 ## Wildcard ##
0161 |`_`|`argument` can be any value of the correct type.|
0162 |:--|:-----------------------------------------------|
0163 |`A<type>()` or `An<type>()`|`argument` can be any value of type `type`.     |
0164 
0165 ## Generic Comparison ##
0166 
0167 |`Eq(value)` or `value`|`argument == value`|
0168 |:---------------------|:------------------|
0169 |`Ge(value)`           |`argument >= value`|
0170 |`Gt(value)`           |`argument > value` |
0171 |`Le(value)`           |`argument <= value`|
0172 |`Lt(value)`           |`argument < value` |
0173 |`Ne(value)`           |`argument != value`|
0174 |`IsNull()`            |`argument` is a `NULL` pointer (raw or smart).|
0175 |`NotNull()`           |`argument` is a non-null pointer (raw or smart).|
0176 |`Ref(variable)`       |`argument` is a reference to `variable`.|
0177 |`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.|
0178 
0179 Except `Ref()`, these matchers make a _copy_ of `value` in case it's
0180 modified or destructed later. If the compiler complains that `value`
0181 doesn't have a public copy constructor, try wrap it in `ByRef()`,
0182 e.g. `Eq(ByRef(non_copyable_value))`. If you do that, make sure
0183 `non_copyable_value` is not changed afterwards, or the meaning of your
0184 matcher will be changed.
0185 
0186 ## Floating-Point Matchers ##
0187 
0188 |`DoubleEq(a_double)`|`argument` is a `double` value approximately equal to `a_double`, treating two NaNs as unequal.|
0189 |:-------------------|:----------------------------------------------------------------------------------------------|
0190 |`FloatEq(a_float)`  |`argument` is a `float` value approximately equal to `a_float`, treating two NaNs as unequal.  |
0191 |`NanSensitiveDoubleEq(a_double)`|`argument` is a `double` value approximately equal to `a_double`, treating two NaNs as equal.  |
0192 |`NanSensitiveFloatEq(a_float)`|`argument` is a `float` value approximately equal to `a_float`, treating two NaNs as equal.    |
0193 
0194 These matchers use ULP-based comparison (the same as used in
0195 [Google Test](http://code.google.com/p/googletest/)). They
0196 automatically pick a reasonable error bound based on the absolute
0197 value of the expected value.  `DoubleEq()` and `FloatEq()` conform to
0198 the IEEE standard, which requires comparing two NaNs for equality to
0199 return false. The `NanSensitive*` version instead treats two NaNs as
0200 equal, which is often what a user wants.
0201 
0202 ## String Matchers ##
0203 
0204 The `argument` can be either a C string or a C++ string object:
0205 
0206 |`ContainsRegex(string)`|`argument` matches the given regular expression.|
0207 |:----------------------|:-----------------------------------------------|
0208 |`EndsWith(suffix)`     |`argument` ends with string `suffix`.           |
0209 |`HasSubstr(string)`    |`argument` contains `string` as a sub-string.   |
0210 |`MatchesRegex(string)` |`argument` matches the given regular expression with the match starting at the first character and ending at the last character.|
0211 |`StartsWith(prefix)`   |`argument` starts with string `prefix`.         |
0212 |`StrCaseEq(string)`    |`argument` is equal to `string`, ignoring case. |
0213 |`StrCaseNe(string)`    |`argument` is not equal to `string`, ignoring case.|
0214 |`StrEq(string)`        |`argument` is equal to `string`.                |
0215 |`StrNe(string)`        |`argument` is not equal to `string`.            |
0216 
0217 `ContainsRegex()` and `MatchesRegex()` use the regular expression
0218 syntax defined
0219 [here](http://code.google.com/p/googletest/wiki/V1_6_AdvancedGuide#Regular_Expression_Syntax).
0220 `StrCaseEq()`, `StrCaseNe()`, `StrEq()`, and `StrNe()` work for wide
0221 strings as well.
0222 
0223 ## Container Matchers ##
0224 
0225 Most STL-style containers support `==`, so you can use
0226 `Eq(expected_container)` or simply `expected_container` to match a
0227 container exactly.   If you want to write the elements in-line,
0228 match them more flexibly, or get more informative messages, you can use:
0229 
0230 | `Contains(e)` | `argument` contains an element that matches `e`, which can be either a value or a matcher. |
0231 |:--------------|:-------------------------------------------------------------------------------------------|
0232 | `Each(e)`     | `argument` is a container where _every_ element matches `e`, which can be either a value or a matcher. |
0233 | `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. |
0234 | `ElementsAreArray(array)` or `ElementsAreArray(array, count)` | The same as `ElementsAre()` except that the expected element values/matchers come from a C-style array. |
0235 | `ContainerEq(container)` | The same as `Eq(container)` except that the failure message also includes which elements are in one container but not the other. |
0236 | `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`. |
0237 
0238 These matchers can also match:
0239 
0240   1. a native array passed by reference (e.g. in `Foo(const int (&a)[5])`), and
0241   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)).
0242 
0243 where the array may be multi-dimensional (i.e. its elements can be arrays).
0244 
0245 ## Member Matchers ##
0246 
0247 |`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_.|
0248 |:------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------|
0249 |`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`.|
0250 |`Pair(m1, m2)`           |`argument` is an `std::pair` whose `first` field matches `m1` and `second` field matches `m2`.                                                |
0251 |`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_.|
0252 
0253 ## Matching the Result of a Function or Functor ##
0254 
0255 |`ResultOf(f, m)`|`f(argument)` matches matcher `m`, where `f` is a function or functor.|
0256 |:---------------|:---------------------------------------------------------------------|
0257 
0258 ## Pointer Matchers ##
0259 
0260 |`Pointee(m)`|`argument` (either a smart pointer or a raw pointer) points to a value that matches matcher `m`.|
0261 |:-----------|:-----------------------------------------------------------------------------------------------|
0262 
0263 ## Multiargument Matchers ##
0264 
0265 Technically, all matchers match a _single_ value. A "multi-argument"
0266 matcher is just one that matches a _tuple_. The following matchers can
0267 be used to match a tuple `(x, y)`:
0268 
0269 |`Eq()`|`x == y`|
0270 |:-----|:-------|
0271 |`Ge()`|`x >= y`|
0272 |`Gt()`|`x > y` |
0273 |`Le()`|`x <= y`|
0274 |`Lt()`|`x < y` |
0275 |`Ne()`|`x != y`|
0276 
0277 You can use the following selectors to pick a subset of the arguments
0278 (or reorder them) to participate in the matching:
0279 
0280 |`AllArgs(m)`|Equivalent to `m`. Useful as syntactic sugar in `.With(AllArgs(m))`.|
0281 |:-----------|:-------------------------------------------------------------------|
0282 |`Args<N1, N2, ..., Nk>(m)`|The tuple of the `k` selected (using 0-based indices) arguments matches `m`, e.g. `Args<1, 2>(Eq())`.|
0283 
0284 ## Composite Matchers ##
0285 
0286 You can make a matcher from one or more other matchers:
0287 
0288 |`AllOf(m1, m2, ..., mn)`|`argument` matches all of the matchers `m1` to `mn`.|
0289 |:-----------------------|:---------------------------------------------------|
0290 |`AnyOf(m1, m2, ..., mn)`|`argument` matches at least one of the matchers `m1` to `mn`.|
0291 |`Not(m)`                |`argument` doesn't match matcher `m`.               |
0292 
0293 ## Adapters for Matchers ##
0294 
0295 |`MatcherCast<T>(m)`|casts matcher `m` to type `Matcher<T>`.|
0296 |:------------------|:--------------------------------------|
0297 |`SafeMatcherCast<T>(m)`| [safely casts](http://code.google.com/p/googlemock/wiki/V1_6_CookBook#Casting_Matchers) matcher `m` to type `Matcher<T>`. |
0298 |`Truly(predicate)` |`predicate(argument)` returns something considered by C++ to be true, where `predicate` is a function or functor.|
0299 
0300 ## Matchers as Predicates ##
0301 
0302 |`Matches(m)(value)`|evaluates to `true` if `value` matches `m`. You can use `Matches(m)` alone as a unary functor.|
0303 |:------------------|:---------------------------------------------------------------------------------------------|
0304 |`ExplainMatchResult(m, value, result_listener)`|evaluates to `true` if `value` matches `m`, explaining the result to `result_listener`.       |
0305 |`Value(value, m)`  |evaluates to `true` if `value` matches `m`.                                                   |
0306 
0307 ## Defining Matchers ##
0308 
0309 | `MATCHER(IsEven, "") { return (arg % 2) == 0; }` | Defines a matcher `IsEven()` to match an even number. |
0310 |:-------------------------------------------------|:------------------------------------------------------|
0311 | `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`. |
0312 | `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`]. |
0313 
0314 **Notes:**
0315 
0316   1. The `MATCHER*` macros cannot be used inside a function or class.
0317   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).
0318   1. You can use `PrintToString(x)` to convert a value `x` of any type to a string.
0319 
0320 ## Matchers as Test Assertions ##
0321 
0322 |`ASSERT_THAT(expression, m)`|Generates a [fatal failure](http://code.google.com/p/googletest/wiki/V1_6_Primer#Assertions) if the value of `expression` doesn't match matcher `m`.|
0323 |:---------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------------|
0324 |`EXPECT_THAT(expression, m)`|Generates a non-fatal failure if the value of `expression` doesn't match matcher `m`.                                                               |
0325 
0326 # Actions #
0327 
0328 **Actions** specify what a mock function should do when invoked.
0329 
0330 ## Returning a Value ##
0331 
0332 |`Return()`|Return from a `void` mock function.|
0333 |:---------|:----------------------------------|
0334 |`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.|
0335 |`ReturnArg<N>()`|Return the `N`-th (0-based) argument.|
0336 |`ReturnNew<T>(a1, ..., ak)`|Return `new T(a1, ..., ak)`; a different object is created each time.|
0337 |`ReturnNull()`|Return a null pointer.             |
0338 |`ReturnPointee(ptr)`|Return the value pointed to by `ptr`.|
0339 |`ReturnRef(variable)`|Return a reference to `variable`.  |
0340 |`ReturnRefOfCopy(value)`|Return a reference to a copy of `value`; the copy lives as long as the action.|
0341 
0342 ## Side Effects ##
0343 
0344 |`Assign(&variable, value)`|Assign `value` to variable.|
0345 |:-------------------------|:--------------------------|
0346 | `DeleteArg<N>()`         | Delete the `N`-th (0-based) argument, which must be a pointer. |
0347 | `SaveArg<N>(pointer)`    | Save the `N`-th (0-based) argument to `*pointer`. |
0348 | `SaveArgPointee<N>(pointer)` | Save the value pointed to by the `N`-th (0-based) argument to `*pointer`. |
0349 | `SetArgReferee<N>(value)` |   Assign value to the variable referenced by the `N`-th (0-based) argument. |
0350 |`SetArgPointee<N>(value)` |Assign `value` to the variable pointed by the `N`-th (0-based) argument.|
0351 |`SetArgumentPointee<N>(value)`|Same as `SetArgPointee<N>(value)`. Deprecated. Will be removed in v1.7.0.|
0352 |`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.|
0353 |`SetErrnoAndReturn(error, value)`|Set `errno` to `error` and return `value`.|
0354 |`Throw(exception)`        |Throws the given exception, which can be any copyable value. Available since v1.1.0.|
0355 
0356 ## Using a Function or a Functor as an Action ##
0357 
0358 |`Invoke(f)`|Invoke `f` with the arguments passed to the mock function, where `f` can be a global/static function or a functor.|
0359 |:----------|:-----------------------------------------------------------------------------------------------------------------|
0360 |`Invoke(object_pointer, &class::method)`|Invoke the {method on the object with the arguments passed to the mock function.                                  |
0361 |`InvokeWithoutArgs(f)`|Invoke `f`, which can be a global/static function or a functor. `f` must take no arguments.                       |
0362 |`InvokeWithoutArgs(object_pointer, &class::method)`|Invoke the method on the object, which takes no arguments.                                                        |
0363 |`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.|
0364 
0365 The return value of the invoked function is used as the return value
0366 of the action.
0367 
0368 When defining a function or functor to be used with `Invoke*()`, you can declare any unused parameters as `Unused`:
0369 ```
0370   double Distance(Unused, double x, double y) { return sqrt(x*x + y*y); }
0371   ...
0372   EXPECT_CALL(mock, Foo("Hi", _, _)).WillOnce(Invoke(Distance));
0373 ```
0374 
0375 In `InvokeArgument<N>(...)`, if an argument needs to be passed by reference, wrap it inside `ByRef()`. For example,
0376 ```
0377   InvokeArgument<2>(5, string("Hi"), ByRef(foo))
0378 ```
0379 calls the mock function's #2 argument, passing to it `5` and `string("Hi")` by value, and `foo` by reference.
0380 
0381 ## Default Action ##
0382 
0383 |`DoDefault()`|Do the default action (specified by `ON_CALL()` or the built-in one).|
0384 |:------------|:--------------------------------------------------------------------|
0385 
0386 **Note:** due to technical reasons, `DoDefault()` cannot be used inside  a composite action - trying to do so will result in a run-time error.
0387 
0388 ## Composite Actions ##
0389 
0390 |`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. |
0391 |:-----------------------|:-----------------------------------------------------------------------------------------------------------------------------|
0392 |`IgnoreResult(a)`       |Perform action `a` and ignore its result. `a` must not return void.                                                           |
0393 |`WithArg<N>(a)`         |Pass the `N`-th (0-based) argument of the mock function to action `a` and perform it.                                         |
0394 |`WithArgs<N1, N2, ..., Nk>(a)`|Pass the selected (0-based) arguments of the mock function to action `a` and perform it.                                      |
0395 |`WithoutArgs(a)`        |Perform action `a` without any arguments.                                                                                     |
0396 
0397 ## Defining Actions ##
0398 
0399 | `ACTION(Sum) { return arg0 + arg1; }` | Defines an action `Sum()` to return the sum of the mock function's argument #0 and #1. |
0400 |:--------------------------------------|:---------------------------------------------------------------------------------------|
0401 | `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`. |
0402 | `ACTION_Pk(Foo, p1, ..., pk) { statements; }` | Defines a parameterized action `Foo(p1, ..., pk)` to execute the given `statements`.   |
0403 
0404 The `ACTION*` macros cannot be used inside a function or class.
0405 
0406 # Cardinalities #
0407 
0408 These are used in `Times()` to specify how many times a mock function will be called:
0409 
0410 |`AnyNumber()`|The function can be called any number of times.|
0411 |:------------|:----------------------------------------------|
0412 |`AtLeast(n)` |The call is expected at least `n` times.       |
0413 |`AtMost(n)`  |The call is expected at most `n` times.        |
0414 |`Between(m, n)`|The call is expected between `m` and `n` (inclusive) times.|
0415 |`Exactly(n) or n`|The call is expected exactly `n` times. In particular, the call should never happen when `n` is 0.|
0416 
0417 # Expectation Order #
0418 
0419 By default, the expectations can be matched in _any_ order.  If some
0420 or all expectations must be matched in a given order, there are two
0421 ways to specify it.  They can be used either independently or
0422 together.
0423 
0424 ## The After Clause ##
0425 
0426 ```
0427 using ::testing::Expectation;
0428 ...
0429 Expectation init_x = EXPECT_CALL(foo, InitX());
0430 Expectation init_y = EXPECT_CALL(foo, InitY());
0431 EXPECT_CALL(foo, Bar())
0432     .After(init_x, init_y);
0433 ```
0434 says that `Bar()` can be called only after both `InitX()` and
0435 `InitY()` have been called.
0436 
0437 If you don't know how many pre-requisites an expectation has when you
0438 write it, you can use an `ExpectationSet` to collect them:
0439 
0440 ```
0441 using ::testing::ExpectationSet;
0442 ...
0443 ExpectationSet all_inits;
0444 for (int i = 0; i < element_count; i++) {
0445   all_inits += EXPECT_CALL(foo, InitElement(i));
0446 }
0447 EXPECT_CALL(foo, Bar())
0448     .After(all_inits);
0449 ```
0450 says that `Bar()` can be called only after all elements have been
0451 initialized (but we don't care about which elements get initialized
0452 before the others).
0453 
0454 Modifying an `ExpectationSet` after using it in an `.After()` doesn't
0455 affect the meaning of the `.After()`.
0456 
0457 ## Sequences ##
0458 
0459 When you have a long chain of sequential expectations, it's easier to
0460 specify the order using **sequences**, which don't require you to given
0461 each expectation in the chain a different name.  <i>All expected<br>
0462 calls</i> in the same sequence must occur in the order they are
0463 specified.
0464 
0465 ```
0466 using ::testing::Sequence;
0467 Sequence s1, s2;
0468 ...
0469 EXPECT_CALL(foo, Reset())
0470     .InSequence(s1, s2)
0471     .WillOnce(Return(true));
0472 EXPECT_CALL(foo, GetSize())
0473     .InSequence(s1)
0474     .WillOnce(Return(1));
0475 EXPECT_CALL(foo, Describe(A<const char*>()))
0476     .InSequence(s2)
0477     .WillOnce(Return("dummy"));
0478 ```
0479 says that `Reset()` must be called before _both_ `GetSize()` _and_
0480 `Describe()`, and the latter two can occur in any order.
0481 
0482 To put many expectations in a sequence conveniently:
0483 ```
0484 using ::testing::InSequence;
0485 {
0486   InSequence dummy;
0487 
0488   EXPECT_CALL(...)...;
0489   EXPECT_CALL(...)...;
0490   ...
0491   EXPECT_CALL(...)...;
0492 }
0493 ```
0494 says that all expected calls in the scope of `dummy` must occur in
0495 strict order. The name `dummy` is irrelevant.)
0496 
0497 # Verifying and Resetting a Mock #
0498 
0499 Google Mock will verify the expectations on a mock object when it is destructed, or you can do it earlier:
0500 ```
0501 using ::testing::Mock;
0502 ...
0503 // Verifies and removes the expectations on mock_obj;
0504 // returns true iff successful.
0505 Mock::VerifyAndClearExpectations(&mock_obj);
0506 ...
0507 // Verifies and removes the expectations on mock_obj;
0508 // also removes the default actions set by ON_CALL();
0509 // returns true iff successful.
0510 Mock::VerifyAndClear(&mock_obj);
0511 ```
0512 
0513 You can also tell Google Mock that a mock object can be leaked and doesn't
0514 need to be verified:
0515 ```
0516 Mock::AllowLeak(&mock_obj);
0517 ```
0518 
0519 # Mock Classes #
0520 
0521 Google Mock defines a convenient mock class template
0522 ```
0523 class MockFunction<R(A1, ..., An)> {
0524  public:
0525   MOCK_METHODn(Call, R(A1, ..., An));
0526 };
0527 ```
0528 See this [recipe](http://code.google.com/p/googlemock/wiki/V1_6_CookBook#Using_Check_Points) for one application of it.
0529 
0530 # Flags #
0531 
0532 | `--gmock_catch_leaked_mocks=0` | Don't report leaked mock objects as failures. |
0533 |:-------------------------------|:----------------------------------------------|
0534 | `--gmock_verbose=LEVEL`        | Sets the default verbosity level (`info`, `warning`, or `error`) of Google Mock messages. |