IngredientClient.js

const gql = require('graphql-tag');

const Ingredient_create = gql`
  mutation (
      $name: String! 
      $file: Upload!
  ){
    ingredientCreate (
      name: $name
      file: $file   
    ){
        id
        name
    } 
  } 
`;


module.exports = { Ingredient_create }

IngredientResolver.js

const fs = require('fs');

storeFile(stream, path) {

       return new Promise((resolve, reject) =>
            stream
                .on('error', error => {
                    if (stream.truncated)
                        // delete the truncated file
                        fs.unlinkSync(path);
                    reject(error);
                })
                .pipe(fs.createWriteStream(path))
                .on('error', error => reject(error))
                .on('finish', () => resolve({ path }))
        );

}


const resolvers = {


    Mutation: {
        async  ingredientCreate(_, args) {

        const { createReadStream, filename, mimetype, encoding } = data_file;
        const path = `${upload_path}/${filename}`;

        const file = await File.create({
            filename,
            mimetype,
            encoding,
            path
        })


        const stream = createReadStream()
        await storeFile(stream, path)

        },



    }

}

module.exports = resolvers;

ingrendientMutation.test.js

const server = require('../../../src/app')
const { Ingredient_create } = require('./IngredientClient')
const { createTestClient } = require('apollo-server-testing');
const { mutate } = createTestClient(server);
const faker = require('faker')
const fs = require('fs')    

describe('Module ingredient all mutations', () => {


    it('should insert a ingrendient with upload of file', async () => {

        var formData = fs.createReadStream(__dirname + '/tomato.png', { encoding: 'utf8' })

        const name = faker.name.findName();

        const result = await mutate({
            mutation: Ingredient_create, variables: {
                name: name,
                file: formData

            },
            context: {
                useMultipart: true
            }

        });

        expect(result.data.ingredientCreate).toBe('test');

    }, 300)

})