handle omitted field propagation for comp1

Author: julmb

src/Data/Aeson/Types/FromJSON.hs

@@ -1028,16 +1028,13 @@ instance (FromJSON1 f) => GFromJSON One (Rec1 f) where
     gParseJSON _opts (From1Args o pj pjl) = fmap Rec1 . liftParseJSON o pj pjl
     {-# INLINE gParseJSON #-}
 
-instance (FromJSON1 f, GFromJSON One g) => GFromJSON One (f :.: g) where
+instance (FromJSON1 f, GFromJSON One g, GOmitFromJSON One g) => GFromJSON One (f :.: g) where
     -- If an occurrence of the last type parameter is nested inside two
     -- composed types, it is decoded by using the outermost type's FromJSON1
     -- instance to generically decode the innermost type:
-    --
-    -- Note: the ommitedField is not passed here.
-    -- This might be related for :.: associated the wrong way in Generics Rep.
     gParseJSON opts fargs =
         let gpj = gParseJSON opts fargs
-        in fmap Comp1 . liftParseJSON Nothing gpj (listParser gpj)
+        in fmap Comp1 . liftParseJSON (gOmittedField fargs) gpj (listParser gpj)
     {-# INLINE gParseJSON #-}
 
 instance FromJSON a => GOmitFromJSON arity (K1 i a) where

src/Data/Aeson/Types/ToJSON.hs

@@ -884,14 +884,15 @@ instance ( WriteProduct arity a, WriteProduct arity b
 
 instance ( ToJSON1 f
          , GToJSON' Value One g
+         , GOmitToJSON Value One g
          ) => GToJSON' Value One (f :.: g)
   where
     -- If an occurrence of the last type parameter is nested inside two
     -- composed types, it is encoded by using the outermost type's ToJSON1
     -- instance to generically encode the innermost type:
     gToJSON opts targs =
       let gtj = gToJSON opts targs in
-      liftToJSON (const False) gtj (listValue gtj) . unComp1
+      liftToJSON (gOmitField targs) gtj (listValue gtj) . unComp1
     {-# INLINE gToJSON #-}
 
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@@ -931,14 +932,15 @@ instance ( EncodeProduct  arity a
 
 instance ( ToJSON1 f
          , GToJSON' Encoding One g
+         , GOmitToJSON Encoding One g
          ) => GToJSON' Encoding One (f :.: g)
   where
     -- If an occurrence of the last type parameter is nested inside two
     -- composed types, it is encoded by using the outermost type's ToJSON1
     -- instance to generically encode the innermost type:
     gToJSON opts targs =
       let gte = gToJSON opts targs in
-      liftToEncoding (const False) gte (listEncoding gte) . unComp1
+      liftToEncoding (gOmitField targs) gte (listEncoding gte) . unComp1
     {-# INLINE gToJSON #-}
 
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