Support for ECMAScript2019 syntax highlight of class privates?

jochemstoel profile image Jochem Stoel ・1 min read

My Visual Studio Code doesn't talk ECMAScript10 yet. Class privates (using # notation) cause syntax errors similar to the ones you get in browsers. I want this to stop. Do I need to update some configuration setting or download an extension? I did not find one. If no syntax definition exists yet then somebody make one.


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Have you tried creating a jsconfig.json with the target set for esnext?

Basically just create a new folder for a project, and then create a new jsconfig.json in that folder with this:
"compilerOptions": {
"target": "esnext"
"exclude": [

I’ll try it myself as soon as I can get access to my computer again, but if it works for you let me know!


According to TC39's GitHub private methods are still a draft, I'm not surprised they are not part of VSCode yet.

You can probably get there with @aimerib 's suggestion, see jsconfig.json for further syntax and you might also want to look into enabling it for the linters.


Really? They are still a draft? Chrome Dev and Chrome Canary already support it. It is not like them to change their minds on something like that.


It's common for browser vendors to start implementing notable features once they reach Stage 2 (IIRC) but keep them behind an experimental-features flag, to let developers play with them IRL and find gaps and edge cases in the spec. Then once the spec reaches Stage 3, sometimes the features come out from behind the flag for wider exposure, since Stage 3 means it's pretty much definitely going to be added to the spec, just maybe with a few more tweaks.

But things can still change until the feature reaches Stage 4, which means "accepted to be added to the next spec release". So I could see IDEs wanting to wait for Stage 4 before adding support, in case the syntax or any other relevant details change in the meantime.


Chrome is full of features that are not standard yet :)