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AutoCheck is a QuickCheck (and later, SmallCheck) clone for C++.

Introduction

QuickCheck is a Haskell library for quickly and easily building unit tests. I will give a brief summary of it here, but if you need more detail, please consult the HaskellWiki.

Unit tests are expressed as properties: functions that perform some computation and return the Boolean value of a post-condition. The arguments of the function form a test case. A canonical example tests that reversing a list twice preserves the original order of the list. In C++, it may be expressed like this:

template <typename T>
bool reverse_prop(const vector<T>& xs) {
  vector<T> ys(xs);
  std::reverse(ys.begin(), ys.end());
  std::reverse(ys.begin(), ys.end());
  return ys == xs;
}

The purpose of QuickCheck is to test such properties with a set of randomly-generated test cases. After the property passes a certain number of tests, it succeeds, and the programmer can, with some level of confidence, presume it works in the general case. If it fails a test, the counterexample is printed to allow the programmer to investigate and debug. Test cases have a notion of growth: they start "small" and grow larger with the hope that the smallest counterexample will be found should the property fail.

Notation

The rest of this documentation follows some conventions:

• Concepts are capitalized, proper nouns, e.g., Arbitrary.
• Function and type names are formatted as code, e.g., [[check]] or [[arbitrary]].
• Template type parameters model the concepts after which they are named, if any.