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|
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE OverloadedLabels #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE UndecidableInstances #-}
{-# OPTIONS_GHC -Wno-unused-local-binds #-}
module Database.Persist.TH.TypeLitFieldDefsSpec where
import GHC.TypeLits
import TemplateTestImports
newtype Finite (n :: Nat) = Finite Int
instance PersistField (Finite n) where
toPersistValue (Finite n) = toPersistValue n
fromPersistValue = fmap Finite . fromPersistValue
instance PersistFieldSql (Finite n) where
sqlType _ = sqlType (Proxy :: Proxy Int)
newtype Labelled (t :: Symbol) = Labelled Int
instance PersistField (Labelled n) where
toPersistValue (Labelled n) = toPersistValue n
fromPersistValue = fmap Labelled . fromPersistValue
instance PersistFieldSql (Labelled n) where
sqlType _ = sqlType (Proxy :: Proxy Int)
mkPersist sqlSettings [persistLowerCase|
WithFinite
one (Finite 1)
twenty (Finite 20)
WithLabelled
one (Labelled "one")
twenty (Labelled "twenty")
|]
spec :: Spec
spec = describe "TypeLitFieldDefs" $ do
it "should support numeric type literal fields in entity definition" $ do
let mkFinite :: Finite 1 -> Finite 20 -> WithFinite
mkFinite = WithFinite
compiles
it "should support string based type literal fields in entity definition" $ do
let mkLabelled :: Labelled "one" -> Labelled "twenty" -> WithLabelled
mkLabelled = WithLabelled
compiles
compiles :: Expectation
compiles = True `shouldBe` True
|
