Correct way to return error in custom service through GraphQL

sunnyson · November 11, 2020, 10:13am

I’m not an expert in GraphQL, but I’m using a custom query & resolver for this approach.

First of all, I’ve create a file at ./api/*/config/schema.graphql.js or for plugins in ./extensions/*/config/schema.graphql.js.
And defined a new query and a resolver for it as shown bellow:

const { sanitizeEntity } = require('strapi-utils');
const _ = require('lodash');
module.exports = {
  query: `
    customOrders(where: JSON): JSON
  `,
  resolver: {
    Query: {
      customOrders: {
        description: 'Find orders',
        resolverOf: 'application::order.order.find', // Will apply the same policy on the custom resolver as the controller's action `find`.
        resolver: async (obj, options, ctx) => {
          //Get orders by using filters from 'where' 
          let entities = await strapi.query('order').find(options.where);

          //Will return an error custom message if there are no orders
          //Also here you can do a custom validation.
          if (_.isEmpty(entities)) {
            return {
              status: '404',
              message: 'No orders found'
            }
          }

          //Will return sanitized orders
          return {
            status: '200',
            orders: entities.map(entity =>
              sanitizeEntity(entity, {
                model: strapi.models.order,
              })
            )
          };
        },
      },
    },
  },
};

Now in GraphQL, I use the newly created Query: customOrders, it returns orders if they are found and custom error message if there are no orders: