Jest/Ionic 4 beta - import { Platform } from '@ionic/angular'; gets SyntaxError: Unexpected token export in Jest testing, not Ionic

Seeing all answers being quite long I have decided to give show what worked for me after reading Jest unit testing no longer works with Ionic 4.

To make it work you need to add to jest.config.ts:

transformIgnorePatterns: [
  "node_modules/(?!@ionic-native|@ionic)"
],

And in tsconfig.spec.json set:

"compilerOptions": {
  "allowJs": true,
},