I’ve a node.js app that is using webpack and babel to transpile to node.js 8.x, I’m trying to get it to transpile to the much older node.js 0.12 to support some older devices, but for some reason the output bundle just looks like regular node8 code with arrow functions and template literals (among other es6 features).

Below are webpack.config.js, .babelrc and package.json, I’ve been trying anything I can think of to try and get it to work so they are bloated with some stuff that’s probably not required.

webpack.config.js (the relevant part):

module.exports = {
    mode: 'production',
    cache: false,
    target: ['es5', 'node0.12'],
    entry: ['./index.js', 'core-js/stable', 'regenerator-runtime/runtime'],
    output: {
        path: path.resolve(__dirname, 'build/'),
        filename: 'index.js',
    },
    resolve: {
        modules: ['node_modules',
            conf.NPM_LOCAL+'/lib/node_modules/',
        ],
        alias: {
            '/util': '../util',
        },
        mainFields: ['main', 'module'],
    },
    module: {
        rules: [{
            test: /.json$/,
            exclude: /(node_modules|race_lib[\/]node_modules|build)/,
            use: 'json-loader',
            type: 'javascript/auto',
        }, {
            test: /.js$/,
            exclude: /(node_modules|race_lib[\/]node_modules|build)/,
            use: [{
                loader: 'babel-loader',
                options: {
                    presets: ['@babel/preset-env', {
                        targets: {
                            node: '0.12'
                        },
                        useBuiltIns: 'usage',
                        corejs: 3,
                        debug: true,
                    }],
                    plugins: [
                        '@babel/plugin-transform-runtime',
                        '@babel/plugin-transform-arrow-functions',
                        '@babel/plugin-transform-template-literals',
                        '@babel/plugin-transform-block-scoping',
                        '@babel/plugin-transform-parameters',
                        '@babel/plugin-transform-destructuring',
                        '@babel/plugin-transform-spread',
                        '@babel/plugin-transform-shorthand-properties',
                    ],
                    sourceType: 'unambiguous',
                },
            }],
        }, {
            test: /race_lib[\/]util[\/].+.js$/,
            use: [{
                loader: 'imports-loader',
                options: {
                    type: 'commonjs',
                    imports: ['single util node_util'],
                    additionalCode: 'var is_node = true, is_rn = false, worker_threads = {isMainThread: true};',
                },
            }],
        }, {
            test: /race_lib[\/]util[\/]config.js$/,
            use: [{
                loader: 'imports-loader',
                options: {
                    type: 'commonjs',
                    imports: 'pure fs.promises',
                },
            }],
        }, {
            test: /race_lib[\/]node_modules[\/].+[\/]index.js$/,
            use: path.resolve(__dirname, 'fs_promises_fixup.js')
        }, {
            test: /node_modules[\/].+.(js|jsx|mjs)$/,
            exclude: /node_modules[\/]@babel[\/]runtime/,
            use: {
                loader: 'babel-loader',
                options: {
                    presets: ['@babel/preset-env'],
                    plugins: [
                        'babel-plugin-transform-globalthis',
                        '@babel/plugin-transform-arrow-functions',
                        '@babel/plugin-transform-template-literals',
                        '@babel/plugin-transform-block-scoping',
                        '@babel/plugin-transform-parameters',
                        '@babel/plugin-transform-destructuring',
                        '@babel/plugin-transform-spread',
                        '@babel/plugin-transform-shorthand-properties',
                    ],
                },
            },
        }],
    },
    stats: {
        errorDetails: true
    },
    externals: [function (_ref, cb) {
        var request = _ref.request;
        if (request.startsWith('node:')) return cb(null, "commonjs ".concat(request.slice(5)));
        cb();
  }, {
    ...
  }],
};

.babelrc:

{
    "presets": [
        ["@babel/preset-env", {
            "targets": {
                "node": "0.12"
            },
            "useBuiltIns": "usage",
            "corejs": 3,
            "debug": true
        }]
    ],
    "plugins": [
        ["@babel/plugin-transform-runtime", {
            "regenerator": true
        }],
        "@babel/plugin-transform-regenerator",
        "babel-plugin-transform-globalthis",
        "@babel/plugin-transform-arrow-functions",
        "@babel/plugin-transform-template-literals",
        "@babel/plugin-transform-block-scoping",
        "@babel/plugin-transform-parameters",
        "@babel/plugin-transform-destructuring",
        "@babel/plugin-transform-spread",
        "@babel/plugin-transform-shorthand-properties"
    ],
    "sourceType": "unambiguous"
}

package.json:

{
    "author": "xxx",
    "dependencies": {
        "@babel/runtime": "7.24.5",
        "core-js": "3.37.1",
        "fs.promises": "0.1.2",
        "regenerator-runtime": "0.14.1"
    },
    "description": "xxx",
    "devDependencies": {
        "@babel/core": "7.24.5",
        "@babel/node": "7.23.9",
        "@babel/plugin-transform-arrow-functions": "^7.24.7",
        "@babel/plugin-transform-block-scoping": "^7.24.7",
        "@babel/plugin-transform-destructuring": "^7.24.8",
        "@babel/plugin-transform-parameters": "^7.24.7",
        "@babel/plugin-transform-regenerator": "7.24.7",
        "@babel/plugin-transform-runtime": "7.24.7",
        "@babel/plugin-transform-shorthand-properties": "^7.24.7",
        "@babel/plugin-transform-spread": "^7.24.7",
        "@babel/plugin-transform-template-literals": "^7.24.7",
        "@babel/preset-env": "7.24.5",
        "amd-to-commonjs-codemod": "^1.2.0",
        "babel-loader": "9.1.3",
        "babel-plugin-transform-globalthis": "1.0.0",
        "imports-loader": "^5.0.0",
        "jscodeshift": "^0.16.1",
        "terser-webpack-plugin": "5.3.10",
        "webpack-cli": "5.1.4",
        "webpack-merge": "5.10.0"
    },
    "license": "xxx",
    "main": "index.js",
    "name": "com.myapp",
    "scripts": {
        "build": "webpack --env development",
        "build_prod": "webpack --env production",
        "clean": "rm -fr build"
    },
    "version": "x.x.x"
}