path: root/googlemock/README.md

## Google Mock ##

The Google C++ mocking framework.

### Overview ###

Google's framework for writing and using C++ mock classes.
It can help you derive better designs of your system and write better tests.

It is inspired by:

  * [jMock](http://www.jmock.org/),
  * [EasyMock](http://www.easymock.org/), and
  * [Hamcrest](http://code.google.com/p/hamcrest/),

and designed with C++'s specifics in mind.

Google mock:

  * lets you create mock classes trivially using simple macros.
  * supports a rich set of matchers and actions.
  * handles unordered, partially ordered, or completely ordered expectations.
  * is extensible by users.

We hope you find it useful!

### Features ###

  * Provides a declarative syntax for defining mocks.
  * Can easily define partial (hybrid) mocks, which are a cross of real
    and mock objects.
  * Handles functions of arbitrary types and overloaded functions.
  * Comes with a rich set of matchers for validating function arguments.
  * Uses an intuitive syntax for controlling the behavior of a mock.
  * Does automatic verification of expectations (no record-and-replay needed).
  * Allows arbitrary (partial) ordering constraints on
    function calls to be expressed,.
  * Lets an user extend it by defining new matchers and actions.
  * Does not use exceptions.
  * Is easy to learn and use.

Please see the project page above for more information as well as the
mailing list for questions, discussions, and development.  There is
also an IRC channel on OFTC (irc.oftc.net) #gtest available.  Please
join us!

Please note that code under [scripts/generator](scripts/generator/) is
from [cppclean](http://code.google.com/p/cppclean/) and released under
the Apache License, which is different from Google Mock's license.

## Getting Started ##

If you are new to the project, we suggest that you read the user
documentation in the following order:

  * Learn the [basics](../../master/googletest/docs/primer.md) of
    Google Test, if you choose to use Google Mock with it (recommended).
  * Read [Google Mock for Dummies](../../master/googlemock/docs/ForDummies.md).
  * Read the instructions below on how to build Google Mock.

You can also watch Zhanyong's [talk](http://www.youtube.com/watch?v=sYpCyLI47rM) on Google Mock's usage and implementation.

Once you understand the basics, check out the rest of the docs:

  * [CheatSheet](../../master/googlemock/docs/CheatSheet.md) - all the commonly used stuff
    at a glance.
  * [CookBook](../../master/googlemock/docs/CookBook.md) - recipes for getting things done,
    including advanced techniques.

If you need help, please check the
[KnownIssues](docs/KnownIssues.md) and
[FrequentlyAskedQuestions](docs/FrequentlyAskedQuestions.md) before
posting a question on the
[discussion group](http://groups.google.com/group/googlemock).


### Using Google Mock Without Google Test ###

Google Mock is not a testing framework itself.  Instead, it needs a
testing framework for writing tests.  Google Mock works seamlessly
with [Google Test](https://github.com/google/googletest), but
you can also use it with [any C++ testing framework](../../master/googlemock/docs/ForDummies.md#using-google-mock-with-any-testing-framework).

### Requirements for End Users ###

Google Mock is implemented on top of [Google Test](
http://github.com/google/googletest/), and depends on it.
You must use the bundled version of Google Test when using Google Mock.

You can also easily configure Google Mock to work with another testing
framework, although it will still need Google Test.  Please read
["Using_Google_Mock_with_Any_Testing_Framework"](
    ../../master/googlemock/docs/ForDummies.md#using-google-mock-with-any-testing-framework)
for instructions.

Google Mock depends on advanced C++ features and thus requires a more
modern compiler. The following are needed to use Google Mock:

#### Linux Requirements ####

  * GNU-compatible Make or "gmake"
  * POSIX-standard shell
  * POSIX(-2) Regular Expressions (regex.h)
  * C++98-standard-compliant compiler (e.g. GCC 3.4 or newer)

#### Windows Requirements ####

  * Microsoft Visual C++ 8.0 SP1 or newer

#### Mac OS X Requirements ####

  * Mac OS X 10.4 Tiger or newer
  * Developer Tools Installed

### Requirements for Contributors ###

We welcome patches. If you plan to contribute a patch, you need to
build Google Mock and its tests, which has further requirements:

  * Automake version 1.9 or newer
  * Autoconf version 2.59 or newer
  * Libtool / Libtoolize
  * Python version 2.3 or newer (for running some of the tests and
    re-generating certain source files from templates)

### Building Google Mock ###

#### Using CMake ####

If you have CMake available, it is recommended that you follow the
[build instructions][gtest_cmakebuild]
as described for Google Test.

If are using Google Mock with an
existing CMake project, the section
[Incorporating Into An Existing CMake Project][gtest_incorpcmake]
may be of particular interest.
To make it work for Google Mock you will need to change

    target_link_libraries(example gtest_main)

to

    target_link_libraries(example gmock_main)

This works because `gmock_main` library is compiled with Google Test.
However, it does not automatically add Google Test includes.
Therefore you will also have to change

    if (CMAKE_VERSION VERSION_LESS 2.8.11)
      include_directories("${gtest_SOURCE_DIR}/include")
    endif()

to

    if (CMAKE_VERSION VERSION_LESS 2.8.11)
      include_directories(BEFORE SYSTEM
        "${gtest_SOURCE_DIR}/include" "${gmock_SOURCE_DIR}/include")
    else()
      target_include_directories(gmock_main SYSTEM BEFORE INTERFACE
        "${gtest_SOURCE_DIR}/include" "${gmock_SOURCE_DIR}/include")
    endif()

This will addtionally mark Google Mock includes as system, which will
silence compiler warnings when compiling your tests using clang with
`-Wpedantic -Wall -Wextra -Wconversion`.


#### Preparing to Build (Unix only) ####

If you are using a Unix system and plan to use the GNU Autotools build
system to build Google Mock (described below), you'll need to
configure it now.

To prepare the Autotools build system:

    cd googlemock
    autoreconf -fvi

To build Google Mock and your tests that use it, you need to tell your
build system where to find its headers and source files.  The exact
way to do it depends on which build system you use, and is usually
straightforward.

This section shows how you can integrate Google Mock into your
existing build system.

Suppose you put Google Mock in directory `${GMOCK_DIR}` and Google Test
in `${GTEST_DIR}` (the latter is `${GMOCK_DIR}/gtest` by default).  To
build Google Mock, create a library build target (or a project as
called by Visual Studio and Xcode) to compile

    ${GTEST_DIR}/src/gtest-all.cc and ${GMOCK_DIR}/src/gmock-all.cc

with

    ${GTEST_DIR}/include and ${GMOCK_DIR}/include

in the system header search path, and

    ${GTEST_DIR} and ${GMOCK_DIR}

in the normal header search path.  Assuming a Linux-like system and gcc,
something like the following will do:

    g++ -isystem ${GTEST_DIR}/include -I${GTEST_DIR} \
        -isystem ${GMOCK_DIR}/include -I${GMOCK_DIR} \
        -pthread -c ${GTEST_DIR}/src/gtest-all.cc
    g++ -isystem ${GTEST_DIR}/include -I${GTEST_DIR} \
        -isystem ${GMOCK_DIR}/include -I${GMOCK_DIR} \
        -pthread -c ${GMOCK_DIR}/src/gmock-all.cc
    ar -rv libgmock.a gtest-all.o gmock-all.o

(We need -pthread as Google Test and Google Mock use threads.)

Next, you should compile your test source file with
${GTEST\_DIR}/include and ${GMOCK\_DIR}/include in the header search
path, and link it with gmock and any other necessary libraries:

    g++ -isystem ${GTEST_DIR}/include -isystem ${GMOCK_DIR}/include \
        -pthread path/to/your_test.cc libgmock.a -o your_test

As an example, the make/ directory contains a Makefile that you can
use to build Google Mock on systems where GNU make is available
(e.g. Linux, Mac OS X, and Cygwin).  It doesn't try to build Google
Mock's own tests.  Instead, it just builds the Google Mock library and
a sample test.  You can use it as a starting point for your own build
script.

If the default settings are correct for your environment, the
following commands should succeed:

    cd ${GMOCK_DIR}/make
    make
    ./gmock_test

If you see errors, try to tweak the contents of
[make/Makefile](make/Makefile) to make them go away.

### Windows ###

The msvc/2005 directory contains VC++ 2005 projects and the msvc/2010
directory contains VC++ 2010 projects for building Google Mock and
selected tests.

Change to the appropriate directory and run "msbuild gmock.sln" to
build the library and tests (or open the gmock.sln in the MSVC IDE).
If you want to create your own project to use with Google Mock, you'll
have to configure it to use the `gmock_config` propety sheet.  For that:

 * Open the Property Manager window (View | Other Windows | Property Manager)
 * Right-click on your project and select "Add Existing Property Sheet..."
 * Navigate to `gmock_config.vsprops` or `gmock_config.props` and select it.
 * In Project Properties | Configuration Properties | General | Additional
   Include Directories, type <path to Google Mock>/include.

### Tweaking Google Mock ###

Google Mock can be used in diverse environments.  The default
configuration may not work (or may not work well) out of the box in
some environments.  However, you can easily tweak Google Mock by
defining control macros on the compiler command line.  Generally,
these macros are named like `GTEST_XYZ` and you define them to either 1
or 0 to enable or disable a certain feature.

We list the most frequently used macros below.  For a complete list,
see file [${GTEST\_DIR}/include/gtest/internal/gtest-port.h](
../googletest/include/gtest/internal/gtest-port.h).

### Choosing a TR1 Tuple Library ###

Google Mock uses the C++ Technical Report 1 (TR1) tuple library
heavily.  Unfortunately TR1 tuple is not yet widely available with all
compilers.  The good news is that Google Test 1.4.0+ implements a
subset of TR1 tuple that's enough for Google Mock's need.  Google Mock
will automatically use that implementation when the compiler doesn't
provide TR1 tuple.

Usually you don't need to care about which tuple library Google Test
and Google Mock use.  However, if your project already uses TR1 tuple,
you need to tell Google Test and Google Mock to use the same TR1 tuple
library the rest of your project uses, or the two tuple
implementations will clash.  To do that, add

    -DGTEST_USE_OWN_TR1_TUPLE=0

to the compiler flags while compiling Google Test, Google Mock, and
your tests.  If you want to force Google Test and Google Mock to use
their own tuple library, just add

    -DGTEST_USE_OWN_TR1_TUPLE=1

to the compiler flags instead.

If you want to use Boost's TR1 tuple library with Google Mock, please
refer to the Boost website (http://www.boost.org/) for how to obtain
it and set it up.

### As a Shared Library (DLL) ###

Google Mock is compact, so most users can build and link it as a static
library for the simplicity.  Google Mock can be used as a DLL, but the
same DLL must contain Google Test as well.  See
[Google Test's README][gtest_readme]
for instructions on how to set up necessary compiler settings.

### Tweaking Google Mock ###

Most of Google Test's control macros apply to Google Mock as well.
Please see [Google Test's README][gtest_readme] for how to tweak them.

### Upgrading from an Earlier Version ###

We strive to keep Google Mock releases backward compatible.
Sometimes, though, we have to make some breaking changes for the
users' long-term benefits.  This section describes what you'll need to
do if you are upgrading from an earlier version of Google Mock.

#### Upgrading from 1.1.0 or Earlier ####

You may need to explicitly enable or disable Google Test's own TR1
tuple library.  See the instructions in section "[Choosing a TR1 Tuple
Library](../googletest/#choosing-a-tr1-tuple-library)".

#### Upgrading from 1.4.0 or Earlier ####

On platforms where the pthread library is available, Google Test and
Google Mock use it in order to be thread-safe.  For this to work, you
may need to tweak your compiler and/or linker flags.  Please see the
"[Multi-threaded Tests](../googletest#multi-threaded-tests
)" section in file Google Test's README for what you may need to do.

If you have custom matchers defined using `MatcherInterface` or
`MakePolymorphicMatcher()`, you'll need to update their definitions to
use the new matcher API (
[monomorphic](./docs/CookBook.md#writing-new-monomorphic-matchers),
[polymorphic](./docs/CookBook.md#writing-new-polymorphic-matchers)).
Matchers defined using `MATCHER()` or `MATCHER_P*()` aren't affected.

Happy testing!

[gtest_readme]: ../googletest/README.md "googletest"
[gtest_cmakebuild]:  ../googletest/README.md#using-cmake "Using CMake"
[gtest_incorpcmake]: ../googletest/README.md#incorporating-into-an-existing-cmake-project "Incorporating Into An Existing CMake Project"