Adding a mutation to a Data Sync client

Prerequisites

You have Node.js and npm installed.

You have completed Queries section and the server is still running.

Modify the client application to perform the mutation:

src/index.js

// gql is a utility function that handles gql queries
import gql from 'graphql-tag';

import { OfflineClient } from '@aerogear/voyager-client';

// connect to the local service.
let config = {
  httpUrl: "http://localhost:4000/graphql",
  wsUrl: "ws://localhost:4000/graphql",
}

async function addPerson() {

  // Actually create the client
  let offlineClient = new OfflineClient(config);
  let client = await offlineClient.init();

  // Execute the mutation
  client.mutate({
      mutation: gql`
       mutation {
         post(name: "John Doe", address: "1 Red Hill") {
           id
         }
       }
       `
    })
    //Print the response of the query
    .then( ({data}) => {
      console.log(data)
    });
}

addPerson();

Build and run the client application.
Browse the client application and check the console output.

It should include an array similar to the following:
```
{
  "data": {
    "post": {
      "id": "person-1"
    }
  }
}
```