Error when adding @angular/pwa: Invalid rule result: Instance of class Promise

[epetre]

This helped by the way:

Ionic 4 -> ng add @angular/pwa

If you are experiencing issues when running ng add @angular/pwa using the latest version of the Angular CLI (6.1.x), for example: ng add @angular/pwa Error: Path "/ngsw-config.json" already exist. Try: npm install --save-dev @angular/cli@next npm install --save-dev @angular-devkit/build-angular@next npm install --save @angular/pwa@next ng add @angular/pwa@next Note: Make sure your project name is the same in ‘package.json’ (“name”: “Brew”) and ‘angular.json’ (“defaultProject”: “Brew”). See…