I've a outdated app that uses very older few packages those doesn't support ES Module as an example file-type
package. So if you setup babel and node HTTP server with and then install file-type package then start building and running will throw error message like below:
Error [ERR_REQUIRE_ESM]: require() of ES Module E:\test\testbabel\node_modules\file-
type\index.js from E:\test\testbabel\dist\index.js not supported.
Instead change the require of E:\test\testbabel\node_modules\file-type\index.js in
E:\test\testbabel\dist\index.js to a dynamic import() which is available in all CommonJS
modules.
at Object.<anonymous> (E:\test\testbabel\dist\index.js:10:17) {
code: 'ERR_REQUIRE_ESM'
}
I tried this on a fresh project though my old project has an outdated config or so, It still throwing this error
Here are my index.js
codes
import http from 'http';
import { fileTypeFromFile } from 'file-type';
const server = http.createServer((req, res) => {
res.end('Hello from the server');
}).listen(4001);
console.log('Server is up and running');
export default server;
file package.json
.
{
"name": "testbabel",
"version": "1.0.0",
"description": "test babel with http or express",
"main": "index.js",
"scripts": {
"build": "babel index.js -d dist",
"start": "npm run build && node dist/index.js"
},
"author": "",
"license": "ISC",
"devDependencies": {
"@babel/cli": "^7.17.10",
"@babel/core": "^7.18.2",
"@babel/plugin-transform-modules-commonjs": "^7.18.2",
"@babel/preset-env": "^7.18.2"
},
"dependencies": {
"file-type": "^17.1.1"
}
}
I just tried to import the package and got the errors above.
attempt:
I thought a converter might help so used @babel/plugin-transform-modules-commonjs
but still didn't help, and seems no effect on including that package
I'm not sure but added some tweaks on package.json
like "type": "module"
"type": "commonjs"
didn't help at all.
what is the easiest solution for this issue and how do we fix it?
Note: I saw people were going back to the supported package instead of new one which doesn't make sense to me as a solution.
Option1(babel with mocha): Rename "index.js" to "index.mjs" and modify file-type's pacakage.json ("index.js" to "index.mjs"), then leave Babel to transpile for you.
// babel-register.js
const babel_register = require("@babel/register").default;
babel_register({
ignore: [
// Only work on Project-wide configuration
// overrides ignore can transpile packages(modules) from node_modules (https://babeljs.io/docs/en/babel-register/#ignores-node_modules-by-default)
],
});
Use babel.config instead of .babelrc
//.mocharc.js
require("./babel-register");
module.exports = {
// https://github.com/mochajs/mocha/blob/v8.4.0/example/config/.mocharc.js
ui: "bdd",
timeout: 5000,
recursive: true,
};
Option2(babel only): Using dynamic import expression
async function doSomething() {
const {fileTypeFromStream} = await import("file-type");
}
and
["@babel/preset-env", {
exclude: ["proposal-dynamic-import"]
}]
Avoiding Babel tanspile dynamic import expression