Schema could not be fetched absinthe error

script · August 1, 2022, 9:48am

I am using absinthe in the project, and I am not that well-versed with Graphql. Recently, I am getting this error in the playground and schema is not generating.

Request: POST //graphql/graphiql
** (exit) an exception was raised:
** (UndefinedFunctionError) function nil.name/0 is undefined
    nil.name()
    (absinthe 1.6.7) lib/absinthe/type/built_ins/introspection.ex:349: Absinthe.Type.BuiltIns.Introspection.render_default_value/4
    (elixir 1.10.4) lib/enum.ex:1396: Enum."-map/2-lists^map/1-0-"/2
    (elixir 1.10.4) lib/enum.ex:1396: Enum."-map/2-lists^map/1-0-"/2
    (absinthe 1.6.7) lib/absinthe/type/built_ins/introspection.ex:333: Absinthe.Type.BuiltIns.Introspection.render_default_value/4

If I run mix absinthe.schema.json --schema SupertrendsWeb.GraphQL.Schema, it gives the same thing and there isn’t much in the error to debug.
Could anyone please suggest how to debug this issue?
@benwilson512
Thanks!

al2o3cr · August 1, 2022, 11:45am

Based on that stacktrace, I’d guess there’s a misconfigured Enum someplace that’s crashing in render_default_value:

github.com

absinthe-graphql/absinthe/blob/646caddbe04624b1c8dfd41903e2040d6180dbbe/lib/absinthe/type/built_ins/introspection.ex#L347-L353


      
          %Absinthe.Type.Field{type: type, name: name, identifier: identifier} ->
            key = adapter.to_external_name(name, :field)
            val = render_default_value(schema, adapter, type, value[identifier])
            "#{key}: #{val}"
          
          
%Absinthe.Type.Enum{values_by_internal_value: values} ->
            values[value].name

benwilson512 · August 1, 2022, 12:37pm

Yeah that looks like a good theory. @script is there anywhere in your schema where you are using an enum type as a field value with a default ?

script · August 2, 2022, 4:17am

Hi @benwilson512 , thank you for your reply, yes , there are couple of enums I have been using in the code, but to exactly figure out which one was wrong was time taking, so I put inspect statements in the introspection.ex file, and figure out the exact enums I need to change, there are a couple of them, and it’s working fine now

script · August 2, 2022, 4:18am

Thank you for your suggestion, indeed that was the issue. Appreciate your prompt response,