webpack.config.js

import path, {dirname} from 'node:path';
import {env} from 'node:process';
import {fileURLToPath} from 'node:url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const dir = './client';
const isDev = env.NODE_ENV === 'development';

const dist = path.resolve(__dirname, 'dist');
const distDev = path.resolve(__dirname, 'dist-dev');
const devtool = isDev ? 'eval' : 'source-map';

const rules = [{
    test: /\.js$/,
    exclude: /node_modules/,
    loader: 'babel-loader',
}];

export default {
    devtool,
    entry: {
        fileop: `${dir}/fileop.js`,
    },
    output: {
        library: 'fileop',
        filename: '[name].js',
        path: isDev ? distDev : dist,
        pathinfo: isDev,
        devtoolModuleFilenameTemplate,
    },
    module: {
        rules,
    },
};

function devtoolModuleFilenameTemplate(info) {
    const resource = info.absoluteResourcePath.replace(__dirname + path.sep, '');
    return `file://fileop/${resource}`;
}