# Why do we need yet another C++ test framework? Good question. For C++ there are quite a number of established frameworks, including (but not limited to), [Google Test](http://code.google.com/p/googletest/), [Boost.Test](http://www.boost.org/doc/libs/1_49_0/libs/test/doc/html/index.html), [CppUnit](http://sourceforge.net/apps/mediawiki/cppunit/index.php?title=Main_Page), [Cute](http://www.cute-test.com), and [many, many more](http://en.wikipedia.org/wiki/List_of_unit_testing_frameworks#C.2B.2B). So what does Catch2 bring to the party that differentiates it from these? Apart from the catchy name, of course. ## Key Features * Quick and easy to get started. Just download two files, add them into your project and you're away. * No external dependencies. As long as you can compile C++14 and have the C++ standard library available. * Write test cases as, self-registering, functions (or methods, if you prefer). * Divide test cases into sections, each of which is run in isolation (eliminates the need for fixtures). * Use BDD-style Given-When-Then sections as well as traditional unit test cases. * Only one core assertion macro for comparisons. Standard C/C++ operators are used for the comparison - yet the full expression is decomposed and lhs and rhs values are logged. * Tests are named using free-form strings - no more couching names in legal identifiers. ## Other core features * Tests can be tagged for easily running ad-hoc groups of tests. * Failures can (optionally) break into the debugger on common platforms. * Output is through modular reporter objects. Basic textual and XML reporters are included. Custom reporters can easily be added. * JUnit xml output is supported for integration with third-party tools, such as CI servers. * A default main() function is provided, but you can supply your own for complete control (e.g. integration into your own test runner GUI). * A command line parser is provided and can still be used if you choose to provided your own main() function. * Alternative assertion macro(s) report failures but don't abort the test case * Good set of facilities for floating point comparisons (`Catch::Approx` and full set of matchers) * Internal and friendly macros are isolated so name clashes can be managed * Data generators (data driven test support) * Hamcrest-style Matchers for testing complex properties * Microbenchmarking support ## Who else is using Catch2? A whole lot of people. According to the 2021 JetBrains C++ ecosystem survey, about 11% of C++ programmers use Catch2 for unit testing, making it the second most popular unit testing framework. You can also take a look at the (incomplete) list of [open source projects](opensource-users.md#top) or the (very incomplete) list of [commercial users of Catch2](commercial-users.md#top) for some idea on who else also uses Catch2. --- See the [tutorial](tutorial.md#top) to get more of a taste of using Catch2 in practice.