42 ULTIMATE TESTER

The Testing Framework You Wish You Had Earlier.

Say goodbye to printf debugging. Say hello to clean, automated, crash-proof testing for your C projects.

42 Ultimate Tester is a fast, lightweight, dependency-free testing framework built for real C developers.

Table of contents

• What's inside?
• Install
• Update and uninstall
• Documentation
• Limitations
• Contribute

✨ What’s inside?

🔥 A testing experience that just works

• No setup, no dependencies, no main function required
• Automatic test discovery
• Clean, readable logs with file + line info
• Isolated execution in forked processes (no more global crashes)

🧠 Smart & powerful checks

• Type-aware assertions (check return values and/or outputs)
• Function-to-function comparison
• Automatic stdout/stderr redirections
• One-liner output capturing
• Custom labels

🛡 Memory checks built-in

• Detect unfreed allocations with precise file/line reporting
• Detect bad malloc protection, null deref, unsafe access, SIGSEGV/SIGBUS, etc.

🧩 Designed for 42 standards

• Pure POSIX C
• Works on Linux and macOS (x86 and ARM)
• Zero external dependencies
• No-sudo install option
• Perfect for libft, ft_printf, gnl, minitalk, and all 42 projects

✌️ Just write what you want to test, and let the framework handle all the complicated stuff.

⚙️ Install

From anywhere, just run:

curl -fsSL https://raw.githubusercontent.com/guillaumeast/42_ultimate_tester/master/1_scripts/install.sh | sh

or:

wget -qO- https://raw.githubusercontent.com/guillaumeast/42_ultimate_tester/master/1_scripts/install.sh | sh

This will:

1. Clone the repo to ~/.42_ultimate_tester/
2. Build the libfut.a static library
3. Link the library and header to your system (global or local)

You can now run your first test in just a few seconds by following this guide ⚡️

✌️ No setup, no dependencies, no editing, no excuses.

🛠️ Update and uninstall

You can update by running the following command:

~/.42_ultimate_tester/1_scripts/update.sh

You can uninstall the framework by running the following command:

~/.42_ultimate_tester/1_scripts/uninstall.sh

To make your life easier, you can set up aliases in your shell config.
For example, if you use zsh shell, run the following commands:

echo "alias fut_update='~/.42_ultimate_tester/1_scripts/update.sh'" >> ~/.zshrc
echo "alias fut_uninstall='~/.42_ultimate_tester/1_scripts/uninstall.sh'" >> ~/.zshrc
source ~/.zshrc

Now you can simply:

• Update with fut_update
• Uninstall with fut_uninstall (but you won't, right?)

📚 Documentation

🚀 Get Started

Your first steps. Write a test, compile it, and run it in less than a minute.

🧩 Test Sets

Learn more about Test Sets and global timeouts.

• Test(): create isolated executable test blocks.

🔀 Redirections

Master stdout and stderr redirections.

• redirect_start(), redirect_read(), redirect_stop(): manually redirect outputs and read them back.
• get_output(): Easily capture outputs in a single line.

✅ Assertions

Understand how to verify correctness, compare behaviors and detect crashes/freezes with safe and flexible assertion tools.

• assert(), assert_eq(), assert_neq(): verify your code logic with type-aware comparisons.
• compare(): compare behaviors of two functions.
• *_label(): use custom labels instead of default ones.

🧠 Memchecks

Catch memory leaks and unsafe memory accesses directly from your tests.

• memleaks(): detect unfreed allocations.
• memsafety(): detect null dereferences, unsafe malloc usage, and crash-prone memory operations.

⚠️ Limitations

• Nested Timeouts: Using assert*()/compare*()/mem*() timeouts inside a Test() which also have a timeout enabled may introduce race conditions. (WIP)
• Struct Comparison: assert_eq*() and assert_neq*() do not support struct comparison yet. (WIP)
• Nested redirections: Using print_stdout() or print_stderr() inside nested redirections is not supported yet. (WIP)
• Logs length: Test set titles and failed assertions logs are limited to 256 characters max. (WIP)

Knowing the limitations is part of mastering the tool.

🤝 Contribute

Contributions are welcome!

Whether you want to fix a bug, improve the documentation, add features, or optimize the core, feel free to open a Pull Request.

How to contribute

1. Fork the repository
2. Create a feature branch:

   git checkout -b feature/my-feature

3. Commit your changes:

   git commit -m "feat: add my feature"

4. Push your branch and open a Pull Request

💡 Make sure your contribution follows the project's structure and conventions.

If you're unsure about something, feel free to open an issue — discussion is welcome.