Quickly create a scratch cabal sandbox and project complete with hspec/QuickCheck tests.

cabal-init

#! /bin/bash

package_name=$(basename `pwd`)

log_file=./cabal-init.log

function fatal() {
    echo "$1.  Examine ${log_file} for more information." 2>&1
    exit 1
}

if ! cabal init --quiet \
                --package-name=${package_name} \
                --category=TBD \
                --version=0.1.0 \
                --license=BSD3 \
                --no-comments \
                --minimal \
                --author='Your Name' \
                --email=you@example.com \
                --homepage=www.example.com \
                --synopsis='this could be the start of something...' \
                --is-library \
                --language=Haskell2010 \
                --source-dir=src \
                --overwrite \
                --expose-module=Library > ${log_file} 2>&1
then
    fatal "cabal init failed"
fi
   
if [ ! -d src ]
then
    mkdir src
fi

if [ ! -d test ]
then
    mkdir test
fi

cat <<-EOF > test/Main.hs

module Main where

import Test.Hspec
import Test.QuickCheck

main :: IO ()
main = hspec $ do
   describe "Specs" $ do
      it "should ..." $ do
         head [23 ..] \`shouldBe\` (23 :: Int)

   describe "QuickChecks" $ do
      it "returns the first element of an *arbitrary* list" $
         property $ \x xs -> head (x:xs) == (x :: Int)

EOF

cat <<EOF > src/Library.hs

module Library where

foo :: Int
foo = 42

EOF

cat <<- EOF >> ${package_name}.cabal

  ghc-options:         -Wall

test-suite suite-one
  build-depends:       base >=4.7 && <4.8, 
                       ${package_name},
                       hspec, 
                       QuickCheck
  hs-source-dirs:      test
  default-language:    Haskell2010
  type:                exitcode-stdio-1.0
  main-is:             Main.hs
  ghc-options:         -Wall

EOF

if ! cabal sandbox init >> ${log_file} 2>&1 
then
    fatal "Could not initialize sandbox"
fi

echo "installing dependencies..."
if ! cabal install --only-dependencies --enable-tests >> ${log_file} 2>&1
then
    fatal "Could not install dependencies"
fi

if ! cabal configure --enable-tests >> ${log_file} 2>&1
then
    fatal "Could not configure project"
fi

echo "building project..."
if ! cabal build >> ${log_file} 2>&1
then
    fatal "Could not build project"
fi

echo "running tests..."
if ! cabal test --show-details=always >> ${log_file} 2>&1
then
    fatal "Could not run tests or there were test failures"
fi

rm ${log_file}

exit 0