Angular 8 - Module not found: Error: Can't resolve 'fs' in

When I try to use

import { readFileSync } from 'fs';

I get the error

Module not found: Error: Can't resolve 'fs'

In fact, when I use readFileSync in my program in VS even the intellisense works fine, but when I run ng serve it comes up with a compiler error.

I've spent hours looking at other SO posts and searching the internet. Nothing has worked. For example, have tried setting "types": ["node"] where previously it was empty. Have tried using a strange /// syntax for importing, but that didn't work either.

I've also tried strange syntax like import { fs } from '@types/node';.

I'm using fs for the following socket.io call:

this.socket = io('https://12.123.1245:1234', { ca: readFileSync('./assets/cert.pem'), rejectUnauthorized: false });