{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# OPTIONS_HADDOCK prune #-}
{-# OPTIONS_GHC -fno-warn-deprecations #-}
-- |
-- Hspec is a Behaviour-Driven Development tool for Haskell programmers. BDD is
-- an approach to software development that combines Test-Driven Development,
-- Domain Driven Design, and Acceptance Test-Driven Planning. Hspec helps you
-- do the TDD part of that equation, focusing on the documentation and design
-- aspects of TDD.
--
-- Hspec (and the preceding intro) are based on the Ruby library RSpec. Much of
-- what applies to RSpec also applies to Hspec. Hspec ties together
-- /descriptions/ of behavior and /examples/ of that behavior. The examples can
-- also be run as tests and the output summarises what needs to be implemented.
module Test.Hspec.Monadic (
-- * Introduction
-- $intro
-- * Types
  Spec
, Example
, Pending

-- * Defining a spec
, describe
, context
, it
, pending

-- * Running a spec
, hspec
, hspecB
, hHspec
, Summary (..)

-- * Interface to the non-monadic API
, runSpecM
, fromSpecList

-- deprecated stuff
, Specs
, descriptions
, hspecX
) where

import           System.IO
import           Test.Hspec.Core (Example)
import qualified Test.Hspec.Core as Core
import qualified Test.Hspec.Runner as Runner
import           Test.Hspec.Runner (Summary (..))
import           Test.Hspec.Pending (Pending)
import qualified Test.Hspec.Pending as Pending

import           Control.Monad.Trans.Writer (Writer, execWriter, tell)

-- $intro
--
-- The three functions you'll use the most are 'hspec', 'describe', and 'it'.
-- Here is an example of functions that format and unformat phone numbers and
-- the specs for them.
--
-- > import Test.Hspec.Monadic
-- > import Test.Hspec.QuickCheck
-- > import Test.Hspec.HUnit ()
-- > import Test.QuickCheck
-- > import Test.HUnit
-- >
-- > main = hspec mySpecs
--
-- Since the specs are often used to tell you what to implement, it's best to
-- start with undefined functions. Once we have some specs, then you can
-- implement each behavior one at a time, ensuring that each behavior is met
-- and there is no undocumented behavior.
--
-- > unformatPhoneNumber :: String -> String
-- > unformatPhoneNumber number = undefined
-- >
-- > formatPhoneNumber :: String -> String
-- > formatPhoneNumber number = undefined
--
-- The 'describe' function takes a list of behaviors and examples bound
-- together with the 'it' function
--
-- > mySpecs = describe "unformatPhoneNumber" $ do
--
-- A boolean expression can act as a behavior's example.
--
-- >   it "removes dashes, spaces, and parenthesies" $
-- >     unformatPhoneNumber "(555) 555-1234" == "5555551234"
--
--
-- The 'pending' function marks a behavior as pending an example. The example
-- doesn't count as failing.
--
-- >   it "handles non-US phone numbers" $
-- >     pending "need to look up how other cultures format phone numbers"
--
--
-- An HUnit 'Test.HUnit.Test' can act as a behavior's example. (must import
-- "Test.Hspec.HUnit")
--
-- >   it "removes the \"ext\" prefix of the extension" $ TestCase $ do
-- >     let expected = "5555551234135"
-- >         actual   = unformatPhoneNumber "(555) 555-1234 ext 135"
-- >     expected @?= actual
--
--
-- An @IO()@ action is treated like an HUnit 'TestCase'. (must import
-- "Test.Hspec.HUnit")
--
-- >   it "converts letters to numbers" $ do
-- >     let expected = "6862377"
-- >         actual   = unformatPhoneNumber "NUMBERS"
-- >     actual @?= expected
--
--
-- The 'property' function allows a QuickCheck property to act as an example.
-- (must import "Test.Hspec.QuickCheck")
--
-- >   it "can add and remove formatting without changing the number" $ property $
-- >     forAll phoneNumber $ \n -> unformatPhoneNumber (formatPhoneNumber n) == n
-- >
-- > phoneNumber :: Gen String
-- > phoneNumber = do
-- >   n <- elements [7,10,11,12,13,14,15]
-- >   vectorOf n (elements "0123456789")
--

type Spec = SpecM ()

newtype SpecM a = SpecM (Writer [Core.Spec] a)
  deriving Monad

-- | Create a document of the given spec and write it to stdout.
--
-- Exit the program with `exitSuccess` if all examples passed, with
-- `exitFailure` otherwise.
hspec :: Spec -> IO ()
hspec = Runner.hspec . runSpecM

-- | Create a document of the given spec and write it to stdout.
--
-- Return `True` if all examples passed, `False` otherwise.
hspecB :: Spec -> IO Bool
hspecB = Runner.hspecB . runSpecM

-- | Create a document of the given specs and write it to the given handle.
--
-- > writeReport filename specs = withFile filename WriteMode (\h -> hHspec h specs)
--
hHspec :: Handle -> Spec -> IO Summary
hHspec h = Runner.hHspec h . runSpecM

-- | Convert a monadic spec into a non-monadic spec.
runSpecM :: Spec -> [Core.Spec]
runSpecM (SpecM specs) = execWriter specs

-- | Convert a non-monadic spec into a monadic spec.
fromSpecList :: [Core.Spec] -> Spec
fromSpecList = SpecM . tell

-- | The @describe@ function combines a list of specs into a larger spec.
describe :: String -> Spec -> Spec
describe label action = SpecM . tell $ [Core.describe label (runSpecM action)]

-- | An alias for `describe`.
context :: String -> Spec -> Spec
context = describe

-- |
-- Create a set of specifications for a specific type being described.  Once
-- you know what you want specs for, use this.
--
-- > describe "abs" $ do
-- >   it "returns a positive number given a negative number" $
-- >     abs (-1) == 1
it :: Example v => String -> v -> Spec
it label action = (SpecM . tell) [Core.it label action]

-- | A pending example.
--
-- If you want to report on a behavior but don't have an example yet, use this.
--
-- > describe "fancyFormatter" $ do
-- >   it "can format text in a way that everyone likes" $
-- >     pending
--
-- You can give an optional reason for why it's pending.
--
-- > describe "fancyFormatter" $ do
-- >   it "can format text in a way that everyone likes" $
-- >     pending "waiting for clarification from the designers"
pending :: String  -> Pending
pending = Pending.pending

{-# DEPRECATED Specs "use Spec instead" #-}
type Specs = SpecM ()

{-# DEPRECATED descriptions "use sequence_ instead" #-}
descriptions :: [Spec] -> Spec
descriptions = sequence_

{-# DEPRECATED hspecX "use hspec instead" #-}
hspecX :: Spec -> IO a
hspecX = Runner.hspecX . runSpecM