This is a testsuite for Haddock that uses the concept of "golden files". That is, it compares output files against a set of reference files. To add a new test: 1) Create a module in the "html-test/src" directory. 2) Run "cabal test". You should now have "html-test/out/.html". The test passes since there is no reference file to compare with. 3) To make a reference file from the output file, do runhaskell accept.lhs Tips and tricks: To "accept" all output files (copy them to reference files), run runhaskell accept.lhs You can run all tests despite failing tests, like so cabal test --test-option=all You can pass extra options to haddock like so cabal test --test-options='all --title="All Tests"'