In Intellij how to set javascript to es6 on a per-file basis?

Question

I know how to set Javascript Language Version to ES6 for the whole project (Language & Frameworks -> Javascript...etc).

But how to set it only for one file ? I have a big ES5 project and would like to start using ES6 one file at a time without having Intellij complaining on all files.

Is there some kind of annotation like "/** ES6 **/" i could use ? Or is it in a panel inside preferences ?

Answer 1

I faced the same question and fortunately this feature was released recently (since IntelliJ 2017.3).

From official website:

The easiest option is to enable the highest language version for the whole project in Preferences | Languages and Frameworks | JavaScript. For example, if you use ES5.1 and JSX, enable JSX (since it’s a superset of ES5.1 and ES6).

Now you can also configure different JavaScript language versions for different folders. Click the … button next to the drop-down with the version, then select a folder and the language version used for its files. The version specified on the main settings page will be applied by default for all other JavaScript files in the project.

_{(source: cloudfront.net)}