Add instances for NonEmptyString (#13)

spago.dhall

@@ -4,7 +4,6 @@
 , dependencies =
   [ "arrays"
   , "bifunctors"
-  , "js-bigints"
   , "control"
   , "datetime"
   , "effect"
@@ -15,6 +14,7 @@
   , "foreign-object"
   , "identity"
   , "integers"
+  , "js-bigints"
   , "js-date"
   , "lists"
   , "maybe"
@@ -25,6 +25,7 @@
   , "partial"
   , "prelude"
   , "record"
+  , "strings"
   , "transformers"
   , "tuples"
   , "typelevel-prelude"

src/Yoga/JSON.purs

@@ -55,6 +55,8 @@ import Data.Maybe (Maybe(..), fromMaybe, fromMaybe', maybe)
 import Data.Newtype (class Newtype)
 import Data.Nullable (Nullable, toMaybe, toNullable)
 import Data.Number as Number
+import Data.String.NonEmpty.Internal (NonEmptyString)
+import Data.String.NonEmpty.Internal as NonEmptyString
 import Data.Symbol (class IsSymbol, reflectSymbol)
 import Data.Traversable (traverse)
 import Data.Tuple (Tuple(..))
@@ -212,6 +214,12 @@ instance ReadForeign BigInt where
 instance ReadForeign String where
   readImpl = readString
 
+instance ReadForeign NonEmptyString where
+  readImpl = readString >=>
+    NonEmptyString.fromString
+      >>> note (pure $ ForeignError "String must not be empty")
+      >>> except
+
 instance ReadForeign Boolean where
   readImpl = readBoolean
 
@@ -402,6 +410,9 @@ instance WriteForeign Foreign where
 instance WriteForeign String where
   writeImpl = unsafeToForeign
 
+instance WriteForeign NonEmptyString where
+  writeImpl = unsafeToForeign
+
 instance WriteForeign Int where
   writeImpl = unsafeToForeign
 

test/BasicsSpec.purs

@@ -12,11 +12,13 @@ import Data.Map as Map
 import Data.Maybe (Maybe(..), fromJust, fromMaybe')
 import Data.Newtype (class Newtype, un)
 import Data.Nullable as Nullable
+import Data.String.NonEmpty (NonEmptyString, nes)
 import Data.Tuple (Tuple(..))
 import Data.Tuple.Nested ((/\))
 import Data.Variant (Variant, inj)
 import Effect.Class (liftEffect)
 import Effect.Now (nowDateTime)
+import Foreign (ForeignError(..))
 import Foreign.Object as Object
 import Js.BigInt.BigInt (BigInt)
 import Js.BigInt.BigInt as BigInt
@@ -133,13 +135,20 @@ spec = describe "En- and decoding" $ do
       roundtrips (UntaggedVariant (erwin "e") ∷ UntaggedVariant (Erwin ()))
       let bareVariant = erwin "e"
       let res = writeJSON (UntaggedVariant bareVariant ∷ UntaggedVariant ExampleVariant)
-      let expected = """"e""""
+      let expected = "\"e\""
       res `shouldEqual` expected
       let
         parsed ∷ _ (UntaggedVariant ExampleVariant)
         parsed = readJSON expected
       (un UntaggedVariant <$> parsed) `shouldEqual` Right bareVariant
 
+  describe "works on non empty strings" do
+    it "roundtrips NonEmptyString" do
+      roundtrips (nes (Proxy :: Proxy "Non-Empty"))
+    it "fails to decode empty strings"  do
+      let (result :: (Either _ NonEmptyString)) = readJSON (show "")
+      result `shouldEqual` Left (pure $ ForeignError "String must not be empty")
+
 type ExampleVariant = ("erwin" ∷ String, "jackie" ∷ Int)
 type ExampleTaggedVariant t v = TaggedVariant t v ExampleVariant