diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,9 @@ +# Changelog for generic-override-aeson + +## 0.0.0.1 + +* Bumping dependency bounds to support aeson 1.5 + +## 0.0.0.0 + +* Initial release diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,75 @@ +# generic-override + +[![Hackage](https://img.shields.io/hackage/v/generic-override.svg?logo=haskell&color=blueviolet)](https://hackage.haskell.org/package/generic-override) +[![Build](https://img.shields.io/travis/estatico/generic-override.svg?logo=travis)](http://travis-ci.org/estatico/generic-override) + +For the associated blog post describing how this works, see +[Overriding Type Class Instances](http://caryrobbins.com/dev/overriding-type-class-instances-2/). + +------------------------- + +This repo contains the following libraries - +* [generic-override](https://hackage.haskell.org/package/generic-override) +* [generic-override-aeson](https://hackage.haskell.org/package/generic-override-aeson) + +------------------------- + +This library provides the ability to override instances used by generic derivation. + +## Example + +```haskell +-- Needed for constructing our 'Override' type in the DerivingVia clause. +import Data.Override (Override(Override), As) +-- Provides aeson support for generic-override (lives in generic-override-aeson). +import Data.Override.Aeson () +-- Basic imports we need for the example. +import Data.Aeson (ToJSON(toJSON)) +import Data.Text (Text) +import qualified Data.Text as Text + +-- | A simple record type. We'll use generic derivation for the 'ToJSON' instance +-- but override the instances used by derivation for the 'String' and 'baz' +-- fields. +data MyRec = MyRec + { foo :: Int + , bar :: String + , baz :: Text + } deriving stock (Show, Eq, Generic) + deriving (ToJSON) + via Override MyRec + '[ -- Derive the 'String' field via 'CharArray'. + String `As` CharArray + -- Derive the 'baz' field via 'Uptext'. + , "baz" `As` Uptext + ] + +-- | Newtype wrapper to override 'ToJSON Text' instances with ones that +-- encode the 'Text' as uppercase. +newtype Uptext = Uptext { unUptext :: Text } + +instance ToJSON Uptext where + toJSON = toJSON . Text.toUpper . unUptext + +-- | Newtype wrapper to override 'ToJSON String' instances with ones that +-- encode the 'String' as a JSON array of characters. +newtype CharArray = CharArray { unCharArray :: String } + +instance ToJSON CharArray where + toJSON = toJSON . map (:[]) . unCharArray +``` + +Let's serialize an example `MyRec` to JSON - + +```haskell +% ghci +> :{ + Data.ByteString.Lazy.Char8.putStrLn + $ Data.Aeson.encode + $ Data.Aeson.toJSON MyRec { foo = 12, bar = "hi", baz = "bye" } + :} +{"foo":12,"bar":["h","i"],"baz":"BYE"} +``` + +For more examples, see the test suite in +[generic-override-aeson](https://github.com/estatico/generic-override/blob/master/generic-override-aeson/test/Test.hs). diff --git a/generic-override-aeson.cabal b/generic-override-aeson.cabal --- a/generic-override-aeson.cabal +++ b/generic-override-aeson.cabal @@ -1,48 +1,53 @@ -cabal-version: 1.12 -name: generic-override-aeson -version: 0.0.0.0 -license: BSD3 -license-file: LICENSE -copyright: 2020 Estatico Studios LLC -maintainer: carymrobbins@gmail.com -author: Cary Robbins -homepage: https://github.com/estatico/generic-override#readme -bug-reports: https://github.com/estatico/generic-override/issues -synopsis: Provides orphan instances necessary for integrating generic-override and aeson +cabal-version: 1.12 +name: generic-override-aeson +version: 0.0.0.2 +license: BSD3 +license-file: LICENSE +copyright: 2020 Estatico Studios LLC +maintainer: carymrobbins@gmail.com +author: Cary Robbins +homepage: https://github.com/estatico/generic-override#readme +bug-reports: https://github.com/estatico/generic-override/issues +synopsis: + Provides orphan instances necessary for integrating generic-override and aeson + description: Please see the README on GitHub at -category: Generics -build-type: Simple +category: Generics +build-type: Simple +extra-source-files: + README.md + CHANGELOG.md + source-repository head - type: git + type: git location: https://github.com/estatico/generic-override library - exposed-modules: - Data.Override.Aeson - hs-source-dirs: src - other-modules: - Paths_generic_override_aeson + exposed-modules: Data.Override.Aeson + hs-source-dirs: src + other-modules: Paths_generic_override_aeson default-language: Haskell2010 build-depends: - aeson >=1.4.5.0 && <1.5, + aeson >=1.4 && <1.6, base >=4.7 && <5, - generic-override >=0.0.0.0 && <0.1 + generic-override >=0.2.0.0 && <0.3 test-suite generic-override-aeson-test - type: exitcode-stdio-1.0 - main-is: Test.hs - hs-source-dirs: test + type: exitcode-stdio-1.0 + main-is: Test.hs + hs-source-dirs: test other-modules: LispCaseAeson Paths_generic_override_aeson + default-language: Haskell2010 - ghc-options: -threaded -rtsopts -with-rtsopts=-N + ghc-options: -threaded -rtsopts -with-rtsopts=-N build-depends: - aeson >=1.4.5.0 && <1.5, + aeson >=1.4 && <1.6, base >=4.7 && <5, - generic-override >=0.0.0.0 && <0.1, + generic-override >=0.2.0.0 && <0.3, generic-override-aeson -any, hspec >=2.7.1 && <2.8, text >=1.2.3.1 && <1.3 diff --git a/src/Data/Override/Aeson.hs b/src/Data/Override/Aeson.hs --- a/src/Data/Override/Aeson.hs +++ b/src/Data/Override/Aeson.hs @@ -15,7 +15,7 @@ module Data.Override.Aeson where import Data.Coerce (Coercible, coerce) -import Data.Override (Override, Overridden(Overridden), Using) +import Data.Override.Internal (Override, Overridden(Overridden), Using) import GHC.Generics (Generic, Rep) import qualified Data.Aeson as Aeson diff --git a/test/Test.hs b/test/Test.hs --- a/test/Test.hs +++ b/test/Test.hs @@ -15,7 +15,7 @@ import Data.Aeson (FromJSON(parseJSON), ToJSON(toJSON), Result(Success), fromJSON) import Data.Aeson.QQ.Simple (aesonQQ) -import Data.Override (Override(Override), As) +import Data.Override (Override(Override), As, With) import Data.Override.Aeson () import Data.Text (Text) import GHC.Generics (Generic) @@ -33,6 +33,7 @@ it "Rec4" testRec4 it "Rec5" testRec5 it "Rec6" testRec6 + it "Rec7" testRec6 newtype Uptext = Uptext { unUptext :: Text } @@ -198,6 +199,31 @@ testRec6 :: IO () testRec6 = do let r = Rec6 { foo = 1, bar = "hi", baz = "bye" } + let j = [aesonQQ| + { + "foo": "1", + "bar": ["h", "i"], + "baz": "bye" + } + |] + toJSON r `shouldBe` j + fromJSON j `shouldBe` Success r + +-- Test 'Override' for both 'ToJSON' and 'FromJSON'. +data Rec7 = Rec7 + { foo :: Int + , bar :: String + , baz :: Text + } deriving stock (Show, Eq, Generic) + deriving (ToJSON, FromJSON) + via Override Rec7 + '[ "foo" `With` Shown + , String `With` CharArray + ] + +testRec7 :: IO () +testRec7 = do + let r = Rec7 { foo = 1, bar = "hi", baz = "bye" } let j = [aesonQQ| { "foo": "1",