MutationType.js

const MoverInputType = new GraphQLInputObjectType(MoverType);

const Mutation = new GraphQLObjectType({
  name: 'Mutation',
  description: 'methods to create mover',
  fields: () => {
    return {
      addMover: {
        type: MoverType,
        args: {
          firstName: { type: new GraphQLNonNull(GraphQLString) },
          lastName: { type: new GraphQLNonNull(GraphQLString) }
        },
        resolve: (source, args) => {
          return Db.models.mover.create({
            firstName: args.firstName,
            lastName: args.lastName
          });
        }
      },
      addCrew: {
        type: new GraphQLList(MoverType),
        args: {
          type: new GraphQLList(MoverInputType)
        },
        resolve: (source, args) => {
          // no clue how to resolve this yet..
        }
      }
    };
  }
});

// I get this error
// Error: Mutation.addCrew(type:) argument type must be Input Type but got: undefined