I'm using the Angular Version 11.1.1.
The command
`ng test --browsers=ChromeHeadlessCI`
is a valid one when I'm using
`@angular-builders/custom-webpack:karma`
in the `test`-section of `angular.js`.
But when I'm using
`@angular-builders/custom-webpack:browser`
in the `test`-section instead, then I get the error above when I'm testing.
Yoa are using
`@angular-builders/custom-webpack:browser`
in the `test`-section in your article instead of `...karma`. Hence testing doesn't work in your article throwing the error above.