Webpack and Module parse failed: Unexpected token

Issue

I've published a package to NPM lately, which includes source. I'm also using webpack in various apps to pull in that source. I found that when I reference code under a node_modules folder (eg; myapp/node_modules/spjsomfluent/src/fuent.ts) I would get:

Module parse failed: Unexpected token (15:11)
You may need an appropriate loader to handle this file type.

Cause:

The webpack rule exclude: /node_modules/ matches any folder in the path. If the source is located under a node_modules folder that error can occur with webpack and ts-loader (TypeScript).
My original rule looked like:

 module: {
        rules: [
            {
                test: /\.tsx?$/,
                use: 'ts-loader',
                exclude: /node_modules/
            }
        ]
    },

Fix:

Change exclude: /node_modules/ to exclude: path.resolve(__dirname, '/node_modules')

This will stop the rule matching node_modules anywhere in the path and instead match it under the apps node_modules folder.

My new rule is:

 module: {
        rules: [
            {
                test: /\.tsx?$/,
                use: 'ts-loader',
                exclude: path.resolve(__dirname, '/node_modules')
            }
        ]
    },