Terminal-Based Rock-Paper-Scissors (C++17)

A lightweight C++17 Rock-Paper-Scissors game focused on clean architecture, safe input handling, and strict test coverage using GoogleTest.

Technical Highlights and Design

• Game Flexibility: The player can configure the total number of rounds and can exit the game at any point during gameplay.
• User-Friendly Interface: Clear, readable terminal output shows current scores and round progress at each step.
• Move Generation Algorithm: Moves are generated using a Pseudo-Random Number Generator (PRNG) based on the Mersenne Twister algorithm (std::mt19937 seeded via std::random_device) to ensure uniform move selection.
• Decoupled Architecture: Core game logic (evaluateResult, parseRoundSize, parsePlayerCommand) consists of pure, stateless functions completely isolated from standard terminal I/O, making unit testing straightforward.
• Modern Error Handling: Uses std::optional to handle invalid inputs cleanly without relying on exceptions for control flow.
• Efficient Input Validation: Uses std::from_chars for high-performance integer parsing without heap allocations or runtime exception overhead.
• Strict Compiler Hygiene: Compiled with -Wall -Wextra -Wpedantic -Werror (/W4 /WX on MSVC) to ensure the codebase remains completely warning-free.

Directory Structure

.
├── CMakeLists.txt
├── include/
│   └── rock_paper_scissors.hpp
├── src/
│   ├── main.cpp
│   └── rock_paper_scissors.cpp
└── test/
    └── test_main.cpp

Prerequisites

• C++17 compatible compiler (Clang 10+, GCC 9+, or MSVC 2019+)
• CMake (version 3.14 or higher)

How to use it

Build Instruction

To configure and build both the main executable and the unit test suite:

#configure the build directory (automatically downloads GoogleTest)
cmake -B build

#compile all targets
cmake --build build

Running the Unit Tests

The GoogleTest suite verifies various move outcomes, string case insensitivity, blank or whitespace inputs, invalid inputs, and numerical overflow boundaries up to std::size_t limits.

#run unit tests directly
./build/test_runner

Executing the Game

#launch the terminal-based game
./build/rps_game

Author

• Author: Tonmoy Sharma
• Email: tonmoy2@icloud.com
• GitHub: github.com/tonmoySh