next.config.js

const withSass = require('@zeit/next-sass');
const withCSS = require('@zeit/next-css');
const withImages = require('next-images');

module.exports = withImages(
    withCSS(
        withSass({
            cssLoaderOptions: {
                url: false,
            },
            webpack(config, options) {
                config.module.rules.push({
                    test: /\.(png|jpg|gif|svg|eot|ttf|woff|woff2)$/,
                    use: {
                        loader: 'url-loader',
                        options: {
                            limit: 100000,
                        },
                    },
                });

                config.module.rules.push({
                    test: /\.json$/,
                    use: {
                        loader: 'json-loader',
                        options: {
                            limit: 100000,
                        },
                    },
                });

                if (!options.isServer) {
                    config.node = {
                        fs: 'empty',
                    };
                }

                return config;
            },
        })
    )
);