Can't get babel loader to apply to dependency

Question

A dependency of my project is using arrow functions and I cannot seem to get babel-loader to transpile the external dependency.

My module section looks like

module: {
        rules: [
            {test: /\.(js|jsx)$/, loader: 'babel-loader'}
        ]
    }

I originally had exclude: /node_modules/(?!superagent)/ in the rules object but removed it to make sure it was not a regex issue.

.babelrc

{
  "presets": [
    "@babel/env",
    "@babel/react"
  ]
}

index.js

import superagent from 'superagent'

superagent.get('http://www.google.com')
    .then(result=>console.log('done'))
    .catch(e=>console.error(e));

The offending dependency in this case is superagent

I created a minimal repo with the config that shows the issue https://github.com/ksmith97/WebpackIssue

I am not sure what else there is to try here

Edit: To be clear this is for IE 11 support.

Answer 1

Move the babelrc config directly to babel loader:

const path = require('path');

module.exports = {
    entry: './index.js',
    mode: 'development',
    devtool: 'source-map',
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'bundle.js'
    },
    module: {
        rules: [{
            test: /\.(jsx?)$/,
            use: {
                loader: 'babel-loader',
                options: {
                    presets: [
                        "@babel/preset-env",
                        "@babel/preset-react"
                    ]
                }
            },
        }]
    }
};

This issue got me by surprise too, but looking at the docs you'll see this:

Searching will stop once a directory containing a package.json is found, so a relative config only applies within a single package.

And in the case of packages inside node_modules, all of them will have their own package.json file, which will make the .babelrc at the root of your project be ignored when the file being compiled is in a package inside node_modules.

The loader config does not have this limitation.