Testing C++ Applications: From Unit Tests to Integration Coverage

The book "Testing C++ Applications" is a practical guide that will help you master the art of writing reliable, maintainable, and easily testable programs in C++. In modern development, quality code is not just working code, but code covered by tests. This book will be your navigator in the world of unit, integration, and functional testing.

Who is this book for?

• For junior and middle level C++ developers who want to introduce testing into their projects.
• For engineers transitioning from other languages (Java, Python, C#) who want to understand the specifics of testing in C++.
• For technical leads looking for ways to improve code quality in their team.
• For senior university students in technical fields studying industrial development.

What will you learn from the book?

• Fundamentals of unit testing: how to write simple and isolated tests for functions and classes.
• Working with popular frameworks: Google Test, Google Mock, Catch2, doctest — their setup, API, and best practices.
• Mock object techniques: isolating tested code from external dependencies (databases, file system, network).
• Test-Driven Development (TDD): how to design application architecture starting from tests.
• Integration testing: verifying component interaction, working with temporary files, network requests.
• Test automation: setting up CI/CD (GitHub Actions, GitLab CI) to run tests on every commit.
• Measuring code quality: coverage (gcov, lcov), static analysis (Clang-Tidy, Cppcheck) and their integration into the process.
• Testing multithreaded and asynchronous applications: finding data races, deadlocks, and non-deterministic errors.

Why should you read this book?

Unlike many theoretical materials, this book is built on real-world examples and cases. You won't just read about tests — you will write them together with the author. Each chapter contains practical tasks and templates that can be immediately applied to your project. Special attention is paid to typical beginner mistakes: how to avoid over-testing code, how to deal with brittle tests, and how to keep the test suite up to date.

The book is suitable both for working on legacy projects (how to add tests to existing code without a complete overhaul) and for starting a new project from scratch using TDD principles. You will learn not only to write tests but also to design code so that it is testable from the start.

After reading the book, you will be able to confidently introduce testing into any C++ project, reduce the number of bugs in production, and speed up the refactoring process through automatic regression checking.

Book contents:

• Chapter 1: Introduction to C++ testing (types of tests, testing pyramid, tooling).
• Chapter 2: Google Test and Google Mock: installation, writing tests, macros, parameterization.
• Chapter 3: Catch2 and doctest: lightweight alternatives, performance comparison.
• Chapter 4: Mock objects: dependency isolation, behavior simulation.
• Chapter 5: TDD in practice: building a calculator and parser from scratch.