The Haskell Test Framework (HTF for short) lets you define and organize unit tests (http://hackage.haskell.org/package/HUnit), QuickCheck properties (https://hackage.haskell.org/package/QuickCheck), and black box tests in an easy and convenient way. HTF uses a custom preprocessor that collects test definitions automatically.
HTF produces highly readable output for failing test cases: it provides exact file name and line number information, it colors and pretty prints expected and actual results, and it displays a diff highlighting the mismatching parts.
sample
directory of HTF's source tree.