How to fix "This dependency was not found" when importing js file?

assets/admin/js/components/formatter.js

export default function addCommas(number)
{
    console.log('aaa');
    return number;
}

assets/admin/js/policy_rater.js

import addCommas from 'components/formatter';

webpack.config.js

// ...
.addEntry('admin-policy', [
    // './assets/admin/js/components/formatter.js',
    "./assets/admin/js/policies.js",
    './assets/admin/js/policy_rater.js',
    './assets/admin/js/components/month-filter.js',
])
// ...

Running command (at least I see it in terminal, I actually run our custom command which probably calls this):

$ /app/node_modules/.bin/encore dev --watch

So very simple import. But when compiling, getting error:

I 79 files written to web/build/act ERROR Failed to compile with 1 errors 11:20:32 AM

This dependency was not found:

components/formatter in ./assets/admin/js/policy_rater.js

To install it, you can run: npm install --save components/formatter

why it even asks me to install if it is not a third party library but just file in my codebase?

Solution

Turns out I needed to import this way:

import addCommas from './components/formatter';