This is a template for codesandbox, you can fork it here: https://codesandbox.io/s/github/wishtack/codesandbox-angular-testing/tree/master/
yarn testyarn jest🐞 There are some memory limitations on codesandbox that can make karma crash.
If you want to use karma and you don't need to run the app simultaneously, then you can simply replace "start": "ng serve..." by "start": "ng test".
Codesandbox will run karma instead of the app which will reduce memory usage.