From bb481d2da65003a6afae672814dd99a9a17bda53 Mon Sep 17 00:00:00 2001 From: Gennadiy Civil Date: Mon, 29 Jul 2019 10:53:47 -0400 Subject: Manual docs tweaks still in preparation for including docs with code pushes --- googlemock/docs/cheat_sheet.md | 81 ++++++++++++++++++++++++++++-------------- googlemock/docs/cook_book.md | 71 ++++++++++++++++++++++++++++++++++-- googlemock/docs/for_dummies.md | 4 ++- googlemock/docs/gmock_faq.md | 4 +++ 4 files changed, 131 insertions(+), 29 deletions(-) (limited to 'googlemock/docs') diff --git a/googlemock/docs/cheat_sheet.md b/googlemock/docs/cheat_sheet.md index e839fa9d..6441a7a8 100644 --- a/googlemock/docs/cheat_sheet.md +++ b/googlemock/docs/cheat_sheet.md @@ -2,6 +2,8 @@ + + ### Defining a Mock Class #### Mocking a Normal Class {#MockClass} @@ -232,7 +234,7 @@ A **matcher** matches a *single* argument. You can use it inside `ON_CALL()` or Built-in matchers (where `argument` is the function argument) are divided into several categories: -## Wildcard +#### Wildcard Matcher | Description :-------------------------- | :----------------------------------------------- @@ -495,6 +497,10 @@ messages, you can use: | `WhenDynamicCastTo(m)` | when `argument` is passed through | : : `dynamic_cast()`, it matches matcher `m`. : + + + + #### Multi-argument Matchers {#MultiArgMatchers} Technically, all matchers match a *single* value. A "multi-argument" matcher is @@ -525,13 +531,25 @@ reorder them) to participate in the matching: 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`. | +| Matcher | Description | +| :------------------------------- | :-------------------------------------- | +| `AllOf(m1, m2, ..., mn)` | `argument` matches all of the matchers | +: : `m1` to `mn`. : +| `AllOfArray({m0, m1, ..., mn})`, | The same as `AllOf()` except that the | +: `AllOfArray(a_container)`, : matchers come from an initializer list, : +: `AllOfArray(begin, end)`, : STL-style container, iterator range, or : +: `AllOfArray(array)`, or : C-style array. : +: `AllOfArray(array, count)` : : +| `AnyOf(m1, m2, ..., mn)` | `argument` matches at least one of the | +: : matchers `m1` to `mn`. : +| `AnyOfArray({m0, m1, ..., mn})`, | The same as `AnyOf()` except that the | +: `AnyOfArray(a_container)`, : matchers come from an initializer list, : +: `AnyOfArray(begin, end)`, : STL-style container, iterator range, or : +: `AnyOfArray(array)`, or : C-style array. : +: `AnyOfArray(array, count)` : : +| `Not(m)` | `argument` doesn't match matcher `m`. | + + #### Adapters for Matchers @@ -550,7 +568,7 @@ You can make a matcher from one or more other matchers: `AddressSatisfies(callback)` and `Truly(callback)` take ownership of `callback`, which must be a permanent callback. -#### Matchers as Predicates {#MatchersAsPredicatesCheat} +#### Using Matchers as Predicates {#MatchersAsPredicatesCheat} | Matcher | Description | | :---------------------------- | :------------------------------------------ | @@ -587,20 +605,13 @@ which must be a permanent callback. 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 | @@ -619,7 +630,7 @@ Matcher | Description #### Side Effects -| Matcher | Description | +| | | | :--------------------------------- | :-------------------------------------- | | `Assign(&variable, value)` | Assign `value` to variable. | | `DeleteArg()` | Delete the `N`-th (0-based) argument, | @@ -652,8 +663,11 @@ Matcher | Description In the following, by "callable" we mean a free function, `std::function`, functor, lambda, or `google3`-style permanent callback. -| Matcher | Description | +| | | | :---------------------------------- | :------------------------------------- | +| `f` | Invoke f with the arguments passed to | +: : the mock function, where f is a : +: : callable (except of google3 callback). : | `Invoke(f)` | Invoke `f` with the arguments passed | : : to the mock function, where `f` can be : : : a global/static function or a functor. : @@ -708,7 +722,7 @@ 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 +#### Default Action | Matcher | Description | | :------------ | :----------------------------------------------------- | @@ -718,9 +732,11 @@ value, and `foo` by reference. **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 | +#### Composite Actions + +| | | | :----------------------------- | :------------------------------------------ | | `DoAll(a1, a2, ..., an)` | Do all actions `a1` to `an` and return the | : : result of `an` in each invocation. The : @@ -734,9 +750,22 @@ composite action - trying to do so will result in a run-time error. : : it. : | `WithoutArgs(a)` | Perform action `a` without any arguments. | -## Defining Actions - -| Matcher | Description | +#### Defining Actions + + + + + + + +
`struct SumAction {`
+  `template `
+  `T operator()(T x, Ty) { return x + y; }`
+ `};` + 		Defines a generic functor that can be used as an action summing its + arguments.
+ +| | | | :--------------------------------- | :-------------------------------------- | | `ACTION(Sum) { return arg0 + arg1; | Defines an action `Sum()` to return the | : }` : sum of the mock function's argument #0 : @@ -755,7 +784,7 @@ The `ACTION*` macros cannot be used inside a function or class. 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. | diff --git a/googlemock/docs/cook_book.md b/googlemock/docs/cook_book.md index a858cd1f..17c26459 100644 --- a/googlemock/docs/cook_book.md +++ b/googlemock/docs/cook_book.md @@ -1,4 +1,4 @@ -## Googletest Mocking (gMock) Cookbook +## gMock Cookbook @@ -824,6 +824,7 @@ A frequently used matcher is `_`, which matches anything: ```cpp EXPECT_CALL(foo, DoThat(_, NotNull())); ``` + #### Combining Matchers {#CombiningMatchers} @@ -1138,6 +1139,8 @@ Note that the predicate function / functor doesn't have to return `bool`. It works as long as the return value can be used as the condition in in statement `if (condition) ...`. + + #### Matching Arguments that Are Not Copyable When you do an `EXPECT_CALL(mock_obj, Foo(bar))`, gMock saves away a copy of @@ -2147,7 +2150,11 @@ own precedence order distinct from the `ON_CALL` precedence order. #### Using Functions/Methods/Functors/Lambdas as Actions {#FunctionsAsActions} If the built-in actions don't suit you, you can use an existing callable -(function, `std::function`, method, functor, lambda as an action. ```cpp +(function, `std::function`, method, functor, lambda as an action. + + + +```cpp using ::testing::_; using ::testing::Invoke; class MockFoo : public Foo { @@ -3239,6 +3246,8 @@ If you are interested in the mock call trace but not the stack traces, you can combine `--gmock_verbose=info` with `--gtest_stack_trace_depth=0` on the test command line. + + #### Running Tests in Emacs If you build and run your tests in Emacs using the `M-x google-compile` command @@ -4175,3 +4184,61 @@ prints the raw bytes in the value and hopes that you the user can figure it out. [googletest's advanced guide](../../googletest/docs/advanced.md#teaching-googletest-how-to-print-your-values) explains how to extend the printer to do a better job at printing your particular type than to dump the bytes. + +### Useful Mocks Created Using gMock + + + + +#### Mock std::function {#MockFunction} + +`std::function` is a general function type introduced in C++11. It is a +preferred way of passing callbacks to new interfaces. Functions are copiable, +and are not usually passed around by pointer, which makes them tricky to mock. +But fear not - `MockFunction` can help you with that. + +`MockFunction` has a mock method `Call()` with the signature: + +```cpp + R Call(T1, ..., Tn); +``` + +It also has a `AsStdFunction()` method, which creates a `std::function` proxy +forwarding to Call: + +```cpp + std::function AsStdFunction(); +``` + +To use `MockFunction`, first create `MockFunction` object and set up +expectations on its `Call` method. Then pass proxy obtained from +`AsStdFunction()` to the code you are testing. For example: + +```cpp +TEST(FooTest, RunsCallbackWithBarArgument) { + // 1. Create a mock object. + MockFunction mock_function; + + // 2. Set expectations on Call() method. + EXPECT_CALL(mock_function, Call("bar")).WillOnce(Return(1)); + + // 3. Exercise code that uses std::function. + Foo(mock_function.AsStdFunction()); + // Foo's signature can be either of: + // void Foo(const std::function& fun); + // void Foo(std::function fun); + + // 4. All expectations will be verified when mock_function + // goes out of scope and is destroyed. +} +``` + +Remember that function objects created with `AsStdFunction()` are just +forwarders. If you create multiple of them, they will share the same set of +expectations. + +Although `std::function` supports unlimited number of arguments, `MockFunction` +implementation is limited to ten. If you ever hit that limit... well, your +callback has bigger problems than being mockable. :-) + + diff --git a/googlemock/docs/for_dummies.md b/googlemock/docs/for_dummies.md index 5433e8b3..b39a0c8b 100644 --- a/googlemock/docs/for_dummies.md +++ b/googlemock/docs/for_dummies.md @@ -1,4 +1,4 @@ -## Googletest Mocking (gMock) for Dummies {#GMockForDummies} +## gMock for Dummies {#GMockForDummies} @@ -206,6 +206,8 @@ choosing the adaptor interface can make your code easier to write and more readable (a net win in the long run), as you can choose `FooAdaptor` to fit your specific domain much better than `Foo` does. + + ### Using Mocks in Tests Once you have a mock class, using it is easy. The typical work flow is: diff --git a/googlemock/docs/gmock_faq.md b/googlemock/docs/gmock_faq.md index 184c501f..8bc45b18 100644 --- a/googlemock/docs/gmock_faq.md +++ b/googlemock/docs/gmock_faq.md @@ -81,6 +81,8 @@ void Bar(int* p); // Neither p nor *p is const. void Bar(const int* p); // p is not const, but *p is. ``` +< + ### I can't figure out why gMock thinks my expectations are not satisfied. What should I do? You might want to run your test with `--gmock_verbose=info`. This flag lets @@ -124,6 +126,8 @@ using ::testing::_; .Times(0); ``` + + ### I have a failed test where gMock tells me TWICE that a particular expectation is not satisfied. Isn't this redundant? When gMock detects a failure, it prints relevant information (the mock function -- cgit v1.2.3