config-overrides.js

const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');
const {resolve} = require("path");

const shouldUseSourceMap = false; //  process.env.GENERATE_SOURCEMAP !== 'false';

module.exports = function override(config, webpackEnv) {
    console.log('overriding webpack config...');

    const isEnvDevelopment = webpackEnv === 'development';
    const isEnvProduction = webpackEnv === 'production';
    const loaders = config.module.rules[1].oneOf;
    console.log(config)

    config.resolve.alias.ws = resolve(__dirname, 'src/alias/ws.js');

    loaders.splice(loaders.length - 1, 0, {
        test: /\.(js|mjs|cjs)$/,
        exclude: /@babel(?:\/|\\{1,2})runtime/,
        loader: require.resolve('babel-loader'),
        options: {
            babelrc: false,
            configFile: false,
            compact: false,
            presets: [
                [
                    require.resolve('babel-preset-react-app/dependencies'),
                    { helpers: true },
                ],
            ],
            cacheDirectory: true,
            // See #6846 for context on why cacheCompression is disabled
            cacheCompression: false,
            // @remove-on-eject-begin
            cacheIdentifier: getCacheIdentifier(
                isEnvProduction
                    ? 'production'
                    : isEnvDevelopment && 'development',
                [
                    'babel-plugin-named-asset-import',
                    'babel-preset-react-app',
                    'react-dev-utils',
                    'react-scripts',
                ]
            ),
            // @remove-on-eject-end
            // Babel sourcemaps are needed for debugging into node_modules
            // code.  Without the options below, debuggers like VSCode
            // show incorrect code and set breakpoints on the wrong lines.
            sourceMaps: shouldUseSourceMap,
            inputSourceMap: shouldUseSourceMap,
        },
    });

    return config;
};