My project is an cordova/ionic based application within angular and typescript with scss.
Where can I set the rules, that the custom elements of Ionic are not an bug anymore?
You can customize this rule (it’s css:S4670 right ?) by creating a new quality profile. If you currently use the Sonar way quality profile then you have to create a new quality profile that inherit from it and then to de-activate and re-activate the rule you want to customize. And while re-activating it inside your new quality profile you should see some parameters that you can change.