== RUNNING ==

Compile the test suite:

  ghc -package test-framework -package test-framework-quickcheck2 \
          -package test-framework-hunit -threaded Example.lhs -o Example

To run the test suite with the default options, simply execute the
resulting binary:

  ./Example

Test options can also be supplied on the command-line:

  ./Example --maximum-generated-tests=5000 +RTS -N2

To see the available options, run:

  ./Example --help

These options can also be specified in the code. An alternate main
function, mainWithOpts, with compile-time options is provided:

  ghc -package test-framework -package test-framework-quickcheck2 \
          -package test-framework-hunit -main-is mainWithOpts     \
          -threaded Example.lhs -o Example
  ./Example

== ATTRIBUTION ==

The example properties come from the parallel QuickCheck driver (pqc),
see http://code.haskell.org/~dons/code/pqc/.  The BSD license is repeated
below, per the licensing conditions of pqc.

== LICENSING ==

    Copyright Don Stewart 2006.

    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.

        * Redistributions in binary form must reproduce the above
          copyright notice, this list of conditions and the following
          disclaimer in the documentation and/or other materials provided
          with the distribution.

        * Neither the name of Don Stewart nor the names of other
          contributors may be used to endorse or promote products derived
          from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

> module Main
>   where
>
>   import Data.Monoid (mempty)
>   import Test.Framework (defaultMain, defaultMainWithOpts, testGroup)
>   import Test.Framework.Options (TestOptions, TestOptions'(..))
>   import Test.Framework.Runners.Options (RunnerOptions, RunnerOptions'(..))
>   import Test.Framework.Providers.HUnit
>   import Test.Framework.Providers.QuickCheck2 (testProperty)
>
>   import Test.QuickCheck
>   import Test.HUnit
>
>   import Data.List
>
>   import Control.Exception (catch)
>   import System.Exit (ExitCode)
>
>   main = defaultMain tests `Control.Exception.catch` exampleFailures
>
>   mainWithOpts = do
>       -- Test options can also be specified in the code. The TestOptions
>       -- type is an instance of the Monoid type class, so the easiest way
>       -- to get an empty set of options is with `mempty`.
>       let empty_test_opts = mempty :: TestOptions
>
>       -- We update the empty TestOptions with our desired values.
>       let my_test_opts = empty_test_opts {
>               topt_maximum_generated_tests = Just 500
>           }
>
>       -- Now we create an empty RunnerOptions in the same way, and add
>       -- our TestOptions to it.
>       let empty_runner_opts = mempty :: RunnerOptions
>       let my_runner_opts = empty_runner_opts {
>               ropt_test_options = Just my_test_opts
>           }
>
>       defaultMainWithOpts tests my_runner_opts
>
>   tests = [
>                 testGroup "Sorting Group 1" [
>                         testProperty "sort1" prop_sort1
>                       , testProperty "sort2" prop_sort2
>                       , testProperty "sort3" prop_sort3
>                   ]
>               , testGroup "Sorting Group 2" [
>                         testGroup "Nested Group 1" [
>                                 testProperty "sort4" prop_sort4
>                               , testProperty "sort5" prop_sort5
>                               , testProperty "sort6" prop_sort6
>                           ]
>                       , testProperty "sort7" prop_sort7
>                       , testCase "sort8" test_sort8
>                       , testCase "sort9" test_sort9
>                   ]
>           ]
>
>     where
>       prop_sort1 xs = sort xs == sortBy compare xs
>           where types = (xs :: [Int])
>
>       prop_sort2 xs =
>           (not (null xs)) ==>
>           (head (sort xs) == minimum xs)
>               where types = (xs :: [Int])
>
>       prop_sort3 xs = (not (null xs)) ==>
>           last (sort xs) == maximum xs
>               where types = (xs :: [Int])
>
>       prop_sort4 xs ys =
>           (not (null xs)) ==>
>           (not (null ys)) ==>
>           (head (sort (xs ++ ys)) == min (minimum xs) (minimum ys))
>               where types = (xs :: [Int], ys :: [Int])
>
>       prop_sort5 xs ys =
>           (not (null xs)) ==>
>           (not (null ys)) ==>
>           (last (sort (xs ++ ys)) == max (maximum xs) (maximum ys))
>               where types = (xs :: [Int], ys :: [Int])
>
>       prop_sort6 xs ys =
>           (not (null xs)) ==>
>           (not (null ys)) ==>
>           (last (sort (xs ++ ys)) == max (maximum xs) (maximum ys))
>               where types = (xs :: [Int], ys :: [Int])
>
>       prop_sort7 xs = if null xs
>                       then error "This property deliberately contains a user error"
>                       else True
>           where types = (xs :: [Int])
>
>       test_sort8 = sort [8, 7, 2, 5, 4, 9, 6, 1, 0, 3] @?= [0..9]
>
>       test_sort9 = error "This test deliberately contains a user error"

The test suite above fails, as we delibarately left errors there.
But because the suite is run as part of CI process, we dismiss failure
exit code with

>   exampleFailures :: ExitCode -> IO ()
>   exampleFailures _ = return ()