HTF

The Haskell Test Framework (HTF for short) lets you define unit tests (http://hunit.sourceforge.net), QuickCheck properties (http://www.cs.chalmers.se/~rjmh/QuickCheck/), and black box tests in an easy and convenient way. HTF uses a custom preprocessor that collects test definitions automatically. Furthermore, the preprocessor allows HTF to report failing test cases with exact file name and line number information. Additionally, HTF tries to produce highly readable output for failing tests: for example, it colors and pretty prints expected and actual results and provides a diff between the two values. The documentation of the Test.Framework.Tutorial module provides a tutorial for HTF. There is also a slightly out-dated blog article (http://factisresearch.blogspot.de/2011/10/new-version-of-htf-with-diffs-colors.html) demonstrating HTF's coloring, pretty-printing and diff functionality.