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), CppUnit, Google Test, Boost.Test, Aeryn, Cute, Fructose and many, many more. Even for Objective-C there are a few, including OCUnit - which now comes bundled with XCode.

So what does Catch bring to the party that differentiates it from these? Apart from a Catchy name, of course.

Key Features

  • Really easy to get started. Just download catch.hpp, #include it and you're away.
  • No external dependencies. As long as you can compile C++11 and have a 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 Windows and Mac.
  • 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.
  • Catch can test itself.
  • Alternative assertion macro(s) report failures but don't abort the test case
  • Floating point tolerance comparisons are built in using an expressive Approx() syntax.
  • Internal and friendly macros are isolated so name clashes can be managed
  • Matchers

Objective-C-specific features

  • Automatically detects if you are using it from an Objective-C project
  • Works with and without ARC with no additional configuration
  • Implement test fixtures using Obj-C classes too (like OCUnit)
  • Additional built in matchers that work with Obj-C types (e.g. string matchers)

Who else is using Catch?

See the list of open source projects using Catch.

See the tutorial to get more of a taste of using Catch in practice

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