QuickCheck is an open source Swift library from TypeLift inspired by the QuickCheck Haskell library that automatically generates random data for testing program properties.
QuickCheck has a very concise syntax, and what makes QuickCheck different is that it can shrink test cases to find exactly what is causing a test to fail.
As the readme states:
What makes QuickCheck unique is the notion of shrinking test cases. When fuzz testing with arbitrary data, rather than simply halt on a failing test, SwiftCheck will begin whittling the data that causes the test to fail down to a minimal counterexample.
You can find SwiftCheck on Github here.
A great library for testing.