A Comprehensive Guide to Setting Up Google Test (GTest) and Google Mock (GMock) for Unit Testing in C++

Introduction

Unit testing is an essential practice in software development that helps ensure the reliability and correctness of your code. When it comes to unit testing in C++, Google Test(GTest) and Google Mock(GMock) are powerful and popular testing frameworks. In this article, we will walk you through the process of setting up GTest and Gmock for unit testing C++.

Credits: https://www.shiksha.com/online-courses/articles/unit-testing-in-software-engineering/

What are Google Test (GTest) and Google Mock (GMock)?

Google Test (Gtest) is a C++ unit testing framework developed by Google. It allows you to write tests for your C++ code and provides various assertion macros for checking expected behavior. Google Mock (GMock) is an extension of GTest that allows you to create mock objects for testing interactions between different parts of your code.

Prerequisites

Before you set up GTest and GMock, you should have the following prerequisites.

1. A C++ development environment(e.g. GCC, Clang, or Visual Studio).
2. CMake (a cross-platform build system).
3. Git(for cloning GTest and GMock repositories).
4. An IDE or text editor of your choice (e.g. Visual Studio Code, CLion, or Xcode).

Installing Google Test and Google Mock

To get started, you need to clone the GTest and GMock repositories from GitHub and build them using CMake. Here’s how to do it

# Clone the GTest and GMock repositories
git clone https://github.com/google/googletest.git
cd googletest
git clone https://github.com/google/googlemock.git

# Build GTest and GMock using CMake
mkdir build
cd build
cmake ..
make

This will build both GTest and GMock, and you’ll have the necessary libraries and headers to include in your C++ project.

Creating a C++ project

Now that you have GTest and GMock set up, it’s time to create a C++ project where you can write your tests. Here are the basic steps:

1. Create a new C++ project or use an existing one.
2. Configure your project to use GTest and GMock by adding their included directories and linking with the corresponding libraries.

Here’s an example CMakeLists.txt file:

cmake_minimum_required(VERSION 3.10)
project(MyProject)

# Include GTest and GMock
include_directories(${CMAKE_SOURCE_DIR}/path/to/googletest/include)
include_directories(${CMAKE_SOURCE_DIR}/path/to/googlemock/include)

# Link with GTest and GMock libraries
link_directories(${CMAKE_SOURCE_DIR}/path/to/build/lib)
target_link_libraries(MyProject gtest gmock)

Make sure to replace `path/to/googletest` and `path/to/googlemock` with the actual paths to the GTest and GMock source directories and update `target_link_libraries` to match your project name.

Writing Your First Test

Now that your project is configured, you can start writing tests. Create a new C++ source file for your tests. and include the necessary GTest and GMock headers.

Here’s a simple example of a GTest test case:

#include <gtest/gtest.h>

TEST(MyTestSuite, MyTestCase) {
    // Your test code here
    ASSERT_TRUE(true);
}

Running Tests

Once you’ve written your tests, it's time to run them. You can use the gtest_main library to create a test runner. To run the tests, build, and execute your project:

mkdir build
cd build
cmake ..
make
./MyProject

The test runner will execute your tests and report the results.

Advanced Testing Techniques

GTest and GMock provide a wide range of features for more advanced testing. including parameterized tests, fixtures, and custom matches. You can explore their features in the official documentation.

Google Test Documentation

Google Mock Documentation

Conclusion

Setting up Google Test(GTest) and Google Mock (GMock) for unit testing in C++ is an essential step in building reliable and robust C++ applications. By following this comprehensive guide. you can harness the power of these testing frameworks to ensure the quality of your code, detect issues early, and simplify the debugging process. Happy unit testing!