Cannot have `Array Int` as a `Var`?

[CGenie]

Hello,

I'm trying to create a GraphQL query template with variables. I have code like this:

type ContextsForNgramsQuery
  = { my_query :: Args
      { my_ids :: Var "my_ids" (Array Int) }
      {...} }

and I use it like this later:

{ my_query: Var :: _ "my_ids" (Array Int) } ==> ...

However, I'm getting this error:

  No type class instance was found for
                                          
    GraphQL.Client.Args.ArgGql Int        
                               (Array Int)
                                          

while solving type class constraint
                                                                         
  GraphQL.Client.Args.ArgGql Int                                         
                             (Var @Symbol @Type "ngrams_ids" (Array Int))

When I replace my_ids to Var "my_ids" Int, this compiles without errors.

Does this mean Array Int is not supported as ArgGql and if so, is there any reason to do this? Here

https://pursuit.purescript.org/packages/purescript-graphql-client/9.3.2/docs/GraphQL.Client.Args#t:ArgGql

I see in particular this instance:

instance argToGqlArray :: ArgGql param arg => ArgGql (Array param) (Array arg)

I guess we could add this as well?

instance ArgGql param arg => ArgGql param (Array arg)

[roryc89]

Does this mean Array Int is not supported as ArgGql and if so, is there any reason to do this?

It should support an Array Int Var if the schema specifies that field as an Array Int.

But it could be an issue with the newer purs version handling class instances differently.

Are you able to add a minimal, reproducible example so that I can see if this is a bug in the library or a schema/value mismatch?

I guess we could add this as well?

instance ArgGql param arg => ArgGql param (Array arg)

That would allow arrays to be used where the schema specifies a single value type so I think would cause runtime errors

[CGenie]

With something like this

https://paste.sr.ht/~cgenie/48ee5986da096f80cfbdce68bc2185ec10d5fc35

I'm getting this error:

Error found:
in module TestArrayInt
at src/Gargantext/Components/GraphQL/TestArrayInt.purs:68:18 - 68:36 (line 68, column 18 - line 68, column 36)

  No type class instance was found for
                                          
    GraphQL.Client.Args.ArgGql Int        
                               (Array Int)
                                          

while solving type class constraint
                                                                     
  GraphQL.Client.Args.ArgGql Int                                     
                             (Var @Symbol @Type "my_ids" (Array Int))
                                                                     
while applying a function queryGql
  of type GqlQuery                                    
            { myquery :: ... @Type                    
                           { my_ids :: ...            
                           }                          
                           { response :: Int          
                           }                          
            }                                         
            t2                                        
            t3                                        
           => ReadForeign t3 => String -> t2 -> Aff t3
  to argument "myquery"
while checking that expression queryGql "myquery"
  has type t0 -> t1
in value declaration runMyQuery

where t0 is an unknown type
      t1 is an unknown type
      t2 is an unknown type
      t3 is an unknown type

See https://github.com/purescript/documentation/blob/master/errors/NoInstanceFound.md for more information,
or to contribute content related to this error.


[error] Failed to build.

I'm using ps 0.15.7.

[CGenie]

Anyone have an idea what's going on here? :)

[CGenie]

As a workaround, I added

newtype Ids = Array Int
instance EncodeJson Ids where
  encodeJson (Ids ids) = encodeJson ids
instance ArgGql Int Ids
instance VarTypeName Ids where
  varTypeName _ = "Ids!"

and replaced Array Int with Ids.

EDIT: It should be

instance VarTypeName Ids where
  varTypeName _ = "[Int!]!"

instead. Otherwise you need to introduce the Ids type on the backend.