How can I use JavaScript private fields in VS Code?

Question

I'm using the proposed private field syntax in my JavaScript but VS Code says this is a syntax error:

The specific error is: Invalid character. ts(1127)

How can I make VS Code understand private fields?

Answer 1

Cause

VS Code uses the TypeScript project to power both its JavaScript and TypeScript IntelliSense. The TypeScript project only added support for private fields in TypeScript 3.8. However the current release of VS Code (1.41) only includes the latest stable TypeScript 3.7 release.

If you see syntax errors for private fields, you are likely using a version of TypeScript in VS Code that does not yet understand private fields.

Workaround

VS Code 1.43 (to be released early March 2020) will include TypeScript 3.8. Until then, you can upgrade your workspace to use a newer typescript version by either:

• Installing this extension

• Following these instructions

Keep in mind that other VS Code extensions—such as linters—may also need to be updated with support for private fields