WebPack: Include Non-Bundle Files In Watch-List to Trigger Rebuild

That is, point to files (somewhere) that are not to be included in any final bundles, but do trigger a rebuild of the aforementioned bundles.

Sidenote:

• Googled around using a few search terms
• Looked at Webpack's watchOptions -- even tried include & included for "./path/to/target/file.json" & /\.\/path\/to\/target\/file\.json/ (just for kicks)
• Skimmed through Webpack Plugins for anything with "Watch", "Trigger" & "Change"

No luck :(

Here is [generally] what I am looking for:

module.exports = {
    entry: modules,  // <-- COMES FROM `./app.json`
    output: {
        filename: '[name].bundle.[hash].js',
        path: path.resolve(__dirname, './dist'),
    },
    ...
    watchOptions: {
        include: './app.json',  // <-- NOT INCLUDED IN BUNDLE (contains `modules` at key `entry`)
    },
};

{
    "environments": {
        "production": {             THESE NEED TO BE WATCHED!!!
            ...                                 |
        },                                      |
        "development": {                        |
            ...                                 |
        }                                       |
    },                                          |
    "modules": {                                V
        "x.component": [ "./src/.../x.component.ts", "./src/.../x.component.scss" ],
        ...
    },
    ...
}

OR

webpack-dev-server --watch ./app.json

Question

How can I watch non-bundle files and trigger a rebuild?