Unit tests in a project with Graphql/Sequlize?

Question

JavaScript

Hey!
I have been looking at a project for a long time to which I need to add unit tests. And I can not find the answer to the question: "What is there to check?"
For example, there is index.js, in which query and mutation are requested:

const query = require('./query');
const mutation = require('./mutation');

module.exports = function resolvers () {
  return {
    Query: query,

    Mutation: mutation,

  };
};

This exports the resolvers() function for the future GraphQL schema. What can be tested here? In addition to checking Queryand Mutationon the object, nothing worthwhile comes to mind. But I understand that such a "test" is not important.
Please tell me how would you implement unit tests for the example above, and for the project with GraphQL and Sequlize in general?