Cabal file with test-suite block and explanation in a USAGE.md file.

README.md

Integrating Test Suites with Cabal Haskell Projects

Basics

Add a Test-Suite block to your project Cabal file like below:

Test-Suite projectname-testsuite
  Type:                     exitcode-stdio-1.0
  Main-is:                  TestSuite.hs
  Build-depends:            base, ....your test framework deps here...

OR:

-- This appears to be contested on ML and in comments below - I have NOT tested this method!
Test-Suite awesomesauce-testsuite
  Type:                 detailed-1.0
  Test-Module:          Awesomesauce.Tests
  Build-depends:        base, QuickCheck, HUnit 

Note: you might need to run: cabal configure --enable-tests and cabal build again.

Now you should be able to just run: cabal test and it should integrate.

Other options

There are two built in test suite Cabal interfaces:

• exitcode-stdio-1.0
• detailed-1.0

The first test suite interface built into Cabal, exitcode-stdio-1.0, depends on the block specifying a Main-is: attribute which is the path of a "main" Haskell file (i.e. a runnable file with a main defined).

The second test suite interface built into Cabal, detailed-1.0, depends on the test-module attribute inside the Test-Suite Cabal block being set to the name of the module to run. This module should export a function named tests with type signature: tests :: [Test]. The Test type can be found in module Distribution.TestSuite. It has two wrapper functions in this module: pure and impure.

Written an internal test library or framework?

Any makers of test frameworks will need to (at a minimum) define instances of the TestOptions and ImpureTestable classes (also exported from Distribution.TestSuite). If the test framework also has a pure runner, you could also define PureTestable class instances for your framework.

QuickCheck & HUnit Support

You will find cabal packages with name prefixes of cabal-test-XXX if your favorite open source Haskell test library or framework (e.g. QuickCheck, HUnit) is supported already.

Test & Have Fun!

awesomesauce.cabal

-- Say you have a Cabal-ized Haskell project called 'awesomesauce'
Name:                awesomesauce
Version:             0.1
Synopsis:            The awesomesauce
Description:         Awesomesauceness for Haskell (as if it needs more?)
License:             BSD3
License-file:        LICENSE
Author:              Susan Potter
Maintainer:          me@susanpotter.net
Copyright:           2011
Category:            Development
Build-type:          Simple
Extra-source-files:  README.md
Cabal-version:       >=1.2

Test-Suite awesomesauce-testsuite
  Type:                 exitcode-stdio-1.0
  Main-is:              ExitCodeTestsExample.hs
  Build-depends:        base, QuickCheck, HUnit

-- OR 
-- This appears to be contested - I have NOT tested this method!
Test-Suite awesomesauce-testsuite
  Type:                 detailed-1.0
  Test-Module:          QCTestModule
  Build-depends:        base, QuickCheck, HUnit, test-framework


-- Then your Executable or Library Cabal sections/blocks under here.

ExitCodeTestsExample.hs

module Main where

import Test.QuickCheck (quickCheck)
import Your.Module (encrypt, decrypt)

prop_reverseReverse :: [Char] -> Bool
prop_reverseReverse s = (reverse . reverse) s == s

prop_encryptDecrypt :: [Char] -> Bool
prop_encryptDecrypt s = (encrypt . decrypt) s == s

main = do
  quickCheck prop_encryptDecrypt
  quickCheck prop_reverseReverse

QCTestModule.hs

module QCTestModule where

import Test.Framework
import Test.Framework.Providers.HUnit
import Test.Framework.Providers.QuickCheck
import Your.Module (encrypt, decrypt)

prop_reverseReverse :: [Char] -> Bool
prop_reverseReverse s = (reverse . reverse) s == s

prop_encryptDecrypt :: [Char] -> Bool
prop_encryptDecrypt s = (encrypt . decrypt) s == s

tests =
  [ test "prop_reverseReverse" prop_reverseReverse
  , test "prop_encryptDecrypt" prop_encryptDecrypt
  , ...
  ]

-- or have a testsuite function that is exported
testSuite = testGroup "Group name"
  [ testProperty "desc1" prop_reverseReverse
  , testProperty "desc2" prop_encryptDecrypt
  ]

You could add something like:

import System.Exit

isPass :: Result -> Bool
isPass (Success n l o) = True
isPass _ = False

check :: Testable prop => prop -> IO ()
check p = do
    r <- quickCheckResult p
    if not $ isPass r then exitFailure else return ()

then your main could look like:

main = do
  check prop_encryptDecrypt
  check prop_reverseReverse