graph_ql_005_mutators_toggle.ts

//
// graphql/schema.ts
//

...
import { Mutation }  from 'graphql/types/mutation';
...

const schemaDefinition = `
    schema {
        query    : Query
        # Add mutation here
        mutation : Mutation 
    }
`;


const typeDefs = [
    schemaDefinition,
    Query,
    Mutation, // <-- And here
    ...types,
];


//
// graphql/types/mutation.ts  
//

...
export const Mutation = `
    type Mutation {
        toggleCard (
            id: String!
        ): Card
    }
`;
...

//
// graphql/resolvers.ts
//

export const resolvers = {
    Query: {
        ...cardsResolver,
        ...cardResolver,
    },
    
    // add mutations
    Mutation: {
        ...toggleCardMutation, 
    },
};

//
// graphql/mutations/toggle-card.ts
//

import { getRepository } from 'typeorm';
import { Card }          from 'entities/card';


export const toggleCardMutation = {
    async toggleCard(_, { id }) {
        const repository = getRepository(Card);
        const card = await repository.findOne({ id });
        const done = !card.done;
        const result = await repository.updateById(id, { done });
        return {
            ...card,
            done,
        };
    }
};