typeErrors.js

import {
  HeroNameQueryVariables,
  HeroNameQuery,
} from './schema';

// ...

const variables: HeroNameQueryVariables = {
  episode: 'JARJAR',
};
// [ts] Type '{ episode: "JARJAR"; }' is not assignable to type 'HeroNameQueryVariables'.
//      Types of property 'episode' are incompatible.
//      Type '"JARJAR"' is not assignable to type 'Episode'.

client.query({
  query: graphqlDocuments['DescribeHero.graphql'],
  variables,
})
.then(({data}: {data: HeroNameQuery}) => {
  data.hero.friends.forEach(friend => console.log(friend.name));
  // [ts] Property 'friends' does not exist on type 'DescribeHeroFragment'.
});