UT: run-time and compile-time C++ unit-testing

A simple and fast compiling unit test library.

Tools

• suite - Write a collection of tests
• "name"_test - Declare a test
• test("name") - Declare a test with a runtime name
• expect - Check a boolean
• throws(func) - Require a call to throw

Features

Single header

To enable compile time testing, set the option UT_COMPILE_TIME to ON. For example:

set(UT_COMPILE_TIME ON)

Runtime testing is always enabled.

Modules support

The library supports C++ 20/23 modules. To enable, set the option UT_ENABLE_MODULES to ON. For example:

set (UT_ENABLE_MODULES ON)

You can then import the library:

import ut;

Please note that modules integration requires compiler and build tools that support import std.

Running Specific Tests

Use the UT_RUN environment variable to run specific tests by name:

# Single test
UT_RUN="test name" ./my_tests

# Multiple tests
UT_RUN="[test1,test2,test3]" ./my_tests

Requirements

• C++23
• CMake 3.31

Example

#include "ut/ut.hpp"

using namespace ut;

suite tests = [] {
   "double"_test = [] {
      double v = 42.1;
      expect(42.1 == v) << "v is not 42.1";
      expect[42.1 == v] << "a fatal error!";
   };

   "double mutable"_test = []() mutable {
      double v = 42.1;
      expect(42.1 == v) << "v is not 42.1";
      expect[42.1 == v] << "oh no!";
   };

   "int"_test = [] {
      expect(5 + 4 == 9) << "bad";
      expect[5 + 4 == 9] << "fatal";
   };

   "int consteval"_test = []() consteval {
      expect(5 + 4 == 9) << "bad";
      expect[5 + 4 == 9] << "fatal";
   };

   "string"_test = [] {
      std::string_view v = "Hello World";
      expect(v == "Hello World");
      expect[v == "Hello World"];
   };

   test("runtime named test") = [] {
      std::string_view v = "Hello World";
      expect(v == "Hello World");
      expect[v == "Hello World"];
   };

   "throws"_test = []() mutable { expect(throws([] { throw std::runtime_error("I throw!"); })); };

   "no throw"_test = []() mutable { expect(not throws([] { return 55; })); };
};

int main() {}