title: What strict typescript type to return from graphql resolver using eslint?
body: <h1>repo</h1>
  <p><a href="https://github.com/inspiraller/apollo-typescript" rel="nofollow noreferrer">https://github.com/inspiraller/apollo-typescript</a></p>
  <p>The code runs but Eslint typescript complains though.</p>
  <p>I get eslint error on:</p>
  <pre><code> Query: {
      players: () =&gt; players
    }
  </code></pre>
  <blockquote>
  <p>Missing return type on function.eslint@typescript-eslint/explicit-module-boundary-types</p>
  </blockquote>
  <h1>index.ts</h1>
  <pre class="lang-js prettyprint-override"><code>import { ApolloServer } from 'apollo-server';
  import typeDefs from './schema';
  import resolvers from './resolvers';
  
  const init = () =&gt; {
    const server: ApolloServer = new ApolloServer({
      typeDefs,
      resolvers
    });
  
    server.listen().then((props: { url: string }) =&gt; {
      const { url } = props;
      console.log(`Server ready at ${url}`);
    });
  };
  
  init();
  </code></pre>
  <h1>schema.ts</h1>
  <pre class="lang-js prettyprint-override"><code>import { gql } from 'apollo-server';
  
  const typeDefs = gql`
    type Player {
      id: String
      name: String
    }
    type Query {
      players: [Player]!
    }
  
    input PlayerInput {
      name: String
    }
  
    type Mutation {
      addPlayer(player: PlayerInput!): Player
    }
  `;
  
  export default typeDefs;
  </code></pre>
  <h1>resolvers.ts</h1>
  <pre class="lang-js prettyprint-override"><code>interface shapePlayer {
    id: string;
    name: string;
  }
  const players: Array&lt;shapePlayer&gt; = [
    {
      id: 'alpha',
      name: 'terry'
    },
    {
      id: 'beta',
      name: 'pc'
    }
  ];
  
  interface shapeResolver {
    Query: {
      players: () =&gt; Array&lt;shapePlayer&gt; | null | undefined | void;
    };
  }
  
  const resolvers: shapeResolver = {
    Query: {
      players: () =&gt; players
    }
  };
  export default resolvers;
  </code></pre>
  <p>I've discovered many alternative libraries to use, ie typegraphql and this seems a good solution for reducing boilerplate typescript types, but it does not provide the answers to what is the strict return type of a query or mutation.</p>
  <p>Any help recommended. thanks</p>