A simple, single-file test harness for C/C++. Allows specifying test cases and benchmarks alongside your code, and running your tests through a simple flag to your main application. Here's an example:

// inside calculator.c:

...

TEST_CASE(test_calculates)
{
    const char* calc_str = "15 5 +";
    int result = calculate(calc_str);

    ASSERT_EQ(result, 20, "%d");  // actual, expected, format
}

// inside main.c

#define LR_IMPLEMENTATION
#include "labrat.h"

int main(int argc, char const *argv[])
{
    LR_PRELUDE(argc, argv);
    
    ... // do what we would do if tests didn't run.
}

# generate the labrat executable
gcc -x c labrat.h -D LR_GEN_EXECUTABLE -o labrat

# run labrat to generate test metadata
./labrat

# compile our program
gcc program.c calculator.c -o program

# run the tests
./program --lr-run-tests

# run benchmarks
./program --lr-run-benchmarks 1000

:: run the setup provided by Visual Studio to get the command line working
"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" amd64

:: generate the labrat executable
cl /TC /DLR_GEN_EXECUTABLE labrat.h

:: run labrat to generate test metadata
labrat.exe

:: compile our program
cl program.c calculator.c

:: run the tests
program.exe --lr-run-tests

:: run benchmarks
program.exe --lr-run-benchmarks 1000

It works by recursively grabbing every source and header file in the directory, tokenizing them, and searching for the TEST_CASE and BENCHMARK tokens. It then builds a labrat_data.c file which includes all of the necessary information for running the tests. Then when you want to run your tests, it just includes this file in such a way that it generates code which handles running the tests.

To me it's an elegant way of writing a library. No fussing with package managers or fussing with the fact that Windows still doesn't even have a decent package manager. Just drop the file in and you're ready. I wish it were my idea, but I actually 100% stole it from here.

There are many, many C/C++ testing frameworks, and I definitely don't claim that labrat is the best choice in all cases. But there are a few things that are nice about it:

• A single header file handles everything, so there's minimal fussing required
• Labrat automatically detects your tests for you - just define them wherever you want to define them and you're all set.
• Labrat doesn't care about your build system, and you don't have to define a separate build for your tests. Just use the LR_PRELUDE macro in your normal entry point, run the labrat binary whenever you add or remove a test, and then labrat will run your tests based on your command line arguments.
• Labrat has first-class support for benchmarking. Just use the BENCHMARK macro, and the --lr-run-benchmarks flag to get a quick and lightweight measure of whether you're making your code faster or slower.