@hackage hspec-golden0.2.2.0

Golden tests store the expected output in a separated file. Each time a golden test is executed the output of the subject under test (SUT) is compared with the expected output. If the output of the SUT changes then the test will fail until the expected output is updated.

hspec-golden allows you to write golden tests using the popular hspec.

describe "myFunc" $
  it "generates the right output with the right params" $
     let output = show $ myFunc params
       in defaultGolden "myFunc" output

Please see the README on GitHub for more information.