Is there any guide for switchting from SonarTS to SonarJS with TypeScript support? Does it happen automatically?
You will want to make sure that you upgrade SonarJS (to v6.1) and SonarTS (to v2.1) at the same time to avoid any issues on the SonarQube server side.
Otherwise, if your project is not already using TypeScript > 3.2.1, it will need to be available at the time of analysis.
And then it is automatically switched?
Indeed, no other actions on your side.