ConversionSpec.hs

{- HLINT ignore "Redundant bracket" -}
{- HLINT ignore "Use camelCase" -}
{- HLINT ignore "Use null" -}

-- |
-- Copyright: © 2022–2025 Jonathan Knowles
-- License: Apache-2.0
--
module Data.MonoidMap.ConversionSpec
    ( spec
    ) where

import Prelude

import Control.Monad
    ( forM_ )
import Data.Function
    ( (&) )
import Data.Map.Strict
    ( Map )
import Data.MonoidMap
    ( MonoidMap, nonNullCount )
import Data.Proxy
    ( Proxy (..) )
import Test.Common
    ( Key, Test, TestType (TestType), makeSpec, property, testTypesMonoidNull )
import Test.Hspec
    ( Spec, describe, it )
import Test.QuickCheck
    ( Fun (..), Property, applyFun2, cover, (===) )

import qualified Data.Foldable as F
import qualified Data.List as List
import qualified Data.List.NonEmpty as NE
import qualified Data.Map.Strict as Map
import qualified Data.MonoidMap as MonoidMap

spec :: Spec
spec = describe "Conversions" $ do

    forM_ testTypesMonoidNull $ \(TestType p) -> specFor (Proxy @Key) p

specFor :: forall k v. Test k v => Proxy k -> Proxy v -> Spec
specFor = makeSpec $ do

    describe "Conversion to and from lists" $ do
        it "prop_fromList_get" $
            prop_fromList_get
                @k @v & property
        it "prop_fromList_toMap" $
            prop_fromList_toMap
                @k @v & property
        it "prop_fromList_toList" $
            prop_fromList_toList
                @k @v & property
        it "prop_toList_fromList" $
            prop_toList_fromList
                @k @v & property
        it "prop_toList_sort" $
            prop_toList_sort
                @k @v & property
        it "prop_fromListWith_get" $
            prop_fromListWith_get
                @k @v & property

    describe "Conversion to and from ordinary maps" $ do
        it "prop_fromMap_toMap" $
            prop_fromMap_toMap
                @k @v & property
        it "prop_toMap_fromMap" $
            prop_toMap_fromMap
                @k @v & property

--------------------------------------------------------------------------------
-- Conversion to and from lists
--------------------------------------------------------------------------------

prop_fromList_get
    :: Test k v => [(k, v)] -> k -> Property
prop_fromList_get kvs k =
    MonoidMap.get k (MonoidMap.fromList kvs)
        ===
        F.foldMap snd (filter ((== k) . fst) kvs)
    & cover 2
        (matchingKeyCount == 0)
        "matchingKeyCount == 0"
    & cover 2
        (matchingKeyCount == 1)
        "matchingKeyCount == 1"
    & cover 2
        (matchingKeyCount == 2)
        "matchingKeyCount == 2"
    & cover 2
        (matchingKeyCount >= 3)
        "matchingKeyCount >= 3"
  where
    matchingKeyCount =
        length $ filter ((== k) . fst) kvs

prop_fromList_toMap
    :: Test k v => [(k, v)] -> Property
prop_fromList_toMap kvs =
    MonoidMap.toMap m === Map.filter (/= mempty) o
    & cover 2
        (MonoidMap.nonNull m && nonNullCount m /= Map.size o)
        "MonoidMap.nonNull m && nonNullCount m /= Map.size o"
    & cover 2
        (MonoidMap.nonNull m && nonNullCount m == Map.size o)
        "MonoidMap.nonNull m && nonNullCount m == Map.size o"
  where
    m = MonoidMap.fromList kvs
    o = Map.fromListWith (flip (<>)) kvs

prop_fromList_toList
    :: Test k v => [(k, v)] -> Property
prop_fromList_toList kvs =
    MonoidMap.toList m === Map.toList (Map.filter (/= mempty) o)
    & cover 2
        (MonoidMap.nonNull m && nonNullCount m /= Map.size o)
        "MonoidMap.nonNull m && nonNullCount m /= Map.size o"
    & cover 2
        (MonoidMap.nonNull m && nonNullCount m == Map.size o)
        "MonoidMap.nonNull m && nonNullCount m == Map.size o"
  where
    m = MonoidMap.fromList kvs
    o = Map.fromListWith (flip (<>)) kvs

prop_toList_fromList
    :: Test k v => MonoidMap k v -> Property
prop_toList_fromList m =
    MonoidMap.fromList (MonoidMap.toList m) === m
    & cover 2
        (MonoidMap.nonNull m)
        "MonoidMap.nonNull m"

prop_toList_sort
    :: Test k v => MonoidMap k v -> Property
prop_toList_sort m =
    List.sortOn fst (MonoidMap.toList m) === MonoidMap.toList m
    & cover 2
        (MonoidMap.nonNull m)
        "MonoidMap.nonNull m"

prop_fromListWith_get
    :: Test k v => Fun (v, v) v -> [(k, v)] -> k -> Property
prop_fromListWith_get (applyFun2 -> f) kvs k =
    MonoidMap.get k (MonoidMap.fromListWith f kvs)
        ===
        maybe mempty
            (F.foldl1 f)
            (NE.nonEmpty (snd <$> filter ((== k) . fst) kvs))
    & cover 2
        (matchingKeyCount == 0)
        "matchingKeyCount == 0"
    & cover 2
        (matchingKeyCount == 1)
        "matchingKeyCount == 1"
    & cover 2
        (matchingKeyCount == 2)
        "matchingKeyCount == 2"
    & cover 2
        (matchingKeyCount >= 3)
        "matchingKeyCount >= 3"
  where
    matchingKeyCount =
        length $ filter ((== k) . fst) kvs

--------------------------------------------------------------------------------
-- Conversion to and from ordinary maps
--------------------------------------------------------------------------------

prop_fromMap_toMap
    :: Test k v => Map k v -> Property
prop_fromMap_toMap o =
    MonoidMap.toMap m === Map.filter (/= mempty) o
    & cover 2
        (MonoidMap.nonNull m && nonNullCount m /= Map.size o)
        "MonoidMap.nonNull m && nonNullCount m /= Map.size o"
    & cover 2
        (MonoidMap.nonNull m && nonNullCount m == Map.size o)
        "MonoidMap.nonNull m && nonNullCount m == Map.size o"
  where
    m = MonoidMap.fromMap o

prop_toMap_fromMap
    :: Test k v => MonoidMap k v -> Property
prop_toMap_fromMap m =
    MonoidMap.fromMap (MonoidMap.toMap m) === m