测试graphql.js

Question

当我尝试从graphql.js获得响应时，我收到错误

{ data: { countries: null },
      errors: 
       [ GraphQLError {
           message: 'ConnectionConfig is not a constructor'
       ] 
}

这是我在里面有架构的jest文件。 使用express-graphql server这个查询工作。

const schema = new GraphQLSchema({
    query: new GraphQLObjectType({
        name: 'Countries',
        fields() {
            return {
                countries: {
                    type: new GraphQLList(Country),
                    args: {
                        id: { type: GraphQLString }
                    },
                    resolve (root, args) {
                        return Db.models.country.findAll({ where: args });
                    }
                }
            }
        }
    })
});

it('Country', () => {
    const query = `{ countries { id } }`;

    graphql(schema, query)
        .then(res => {
            console.log(res);
        })

});