How to use proxyquire with Typescript compiling to es6/commonjs

_HowToUseProxyquireInTS.md

We hit some trouble using proxyquire in our Typescript which is our express server. The problem was, with our Typescript setup, module exports weren't transpiled into module.exports variables. This was because we were compiling to commonjs in es6. We found no other library to manage this, so we hacked the code to include a module.exports variable for proxyquire to hook into.

index.ts

import * as library from 'external-library'


// Proxyquire uses Module which will return module.exports, so it's needed here
export default module.exports = () => {
    if (!libraryInstance) {
        libraryInstance = library();
    }
    return libraryInstance;
};

test-index.ts

import * as proxyquire from 'proxyquire';

const database = proxyquire('./index', {
    'external-library' : () => /* do some logic here*/
});

// do tests using the database object