GraphQL error - argument type must be Input Type but got: undefined

Question

I have

export const getPicture = {
    type: GraphPicture,
    args: {
        type: new GraphQLNonNull(GraphQLInt)
    },
    resolve(_, args) {
        return Picture.findByPrimary(args.id);
    }
};

export const getPictureList = {
    type: new GraphQLList(GraphPicture),
    resolve(_, __, session) {
        return Picture.findAll({where: {owner: session.userId}});
    }
};

and

const query = new GraphQLObjectType({
    name: 'Queries',
    fields: () => {
        return {
            getPictureList: getPictureList,
            getPicture: getPicture
        }
    }
});

const schema = new GraphQLSchema({
    query: query,
    mutation: mutation
});

Which throws:

Error: Queries.getPicture(type:) argument type must be Input Type but got: undefined.

getPictureList works fine, getPicture fails.

I have tried making getPicture a GraphQLLIst, doesn't help.

I have tried making the args type an Input Type, doesn't help.

Any ideas about what is going on here

The stack trace is:

Error: Queries.getPicture(type:) argument type must be Input Type but got: undefined.
at invariant (/home/jrootham/dev/trytheseon/node_modules/graphql/jsutils/invariant.js:19:11)
at /home/jrootham/dev/trytheseon/node_modules/graphql/type/definition.js:307:33
at Array.map (native)
at /home/jrootham/dev/trytheseon/node_modules/graphql/type/definition.js:304:52
at Array.forEach (native)
at defineFieldMap (/home/jrootham/dev/trytheseon/node_modules/graphql/type/definition.js:293:14)
at GraphQLObjectType.getFields (/home/jrootham/dev/trytheseon/node_modules/graphql/type/definition.js:250:46)
at /home/jrootham/dev/trytheseon/node_modules/graphql/type/schema.js:224:27
at typeMapReducer (/home/jrootham/dev/trytheseon/node_modules/graphql/type/schema.js:236:7)
at Array.reduce (native)
at new GraphQLSchema (/home/jrootham/dev/trytheseon/node_modules/graphql/type/schema.js:104:34)
at Object.<anonymous> (/home/jrootham/dev/trytheseon/server/graphQL.js:45:16)
at Module._compile (module.js:399:26)
at normalLoader (/usr/lib/node_modules/babel/node_modules/babel-core/lib/babel/api/register/node.js:160:5)
at Object.require.extensions.(anonymous function) [as .js] (/usr/lib/node_modules/babel/node_modules/babel-core/lib/babel/api/register/node.js:173:7)
at Module.load (module.js:345:32)
at Function.Module._load (module.js:302:12)
at Module.require (module.js:355:17)
at require (internal/module.js:13:17)
at Object.<anonymous> (/home/jrootham/dev/trytheseon/devServer.js:14:44)
at Module._compile (module.js:399:26)
at normalLoader (/usr/lib/node_modules/babel/node_modules/babel-core/lib/babel/api/register/node.js:160:5)

Answer 1

Just for reference, I got here searching the same error just not with undefined, but with my own Product type:

... argument * must be Input Type but got Product

Turned out that in GraphQL what you pass to a Mutation should be either scalar type (String, Integer, ...) or user defined input type, not type type.

http://graphql.org/graphql-js/mutations-and-input-types/

input ProductInput {
  id: ID
  name: String
}

I was trying to pass in my Product type:

type Product {
  id: ID
  name: String
}

This feels a bit redundant, but guess, I'll be glad for having it separated later.

Answer 2

The problem isn't the return type of the query but the type you have specified to your args.

export const getPicture = {
    type: GraphPicture,
    args: {
        type: new GraphQLNonNull(GraphQLInt)
    },
    resolve(_, args) {
        return Picture.findByPrimary(args.id);
    }
};

Assuming you meant to have an argument named "type" it should be:

export const getPicture = {
    type: GraphPicture,
    args: {
        type: {
             type: new GraphQLNonNull(GraphQLInt)
        }
    },
    resolve(_, args) {
        return Picture.findByPrimary(args.id);
    }
};

here is an example from the graphql-js repo:

hero: {
  type: characterInterface,
  args: {
    episode: {
      description: 'If omitted, returns the hero of the whole saga. If ' +
                   'provided, returns the hero of that particular episode.',
      type: episodeEnum
    }
  },
  resolve: (root, { episode }) => getHero(episode),
},

See the full schema from the graphql-js repo here: https://github.com/graphql/graphql-js/blob/master/src/tests/starWarsSchema.js