Parsing error: Unexpected character '#'

[limpid-kzonix]

Please describe what the rule should do:
Support Private class fields

What new ECMAScript feature does this rule relate to?
Private class fields

What category of rule is this? (place an "X" next to just one item)

[ ] Warns about a potential error (problem)
[ ] Suggests an alternate way of doing something (suggestion)
[ X ] Other (Don't complain about private class fields with error: ESLint: Parsing error: Unexpected character '#')

Provide 2-3 code examples that this rule will warn about:

export class Example {
  #privateClassField

  constructor() {
    this.#privateClassField = ...
  }
 

Why should this rule be included in ESLint (instead of a plugin)?
This feature already supported in LTS version of node.

Are you willing to submit a pull request to implement this rule?
No

[mdjermanovic]

Hi @limpid-kzonix, thanks for the issue!

The class fields proposal is currently in stage 3.

Per our policy about experimental features, ESLint's default parser will support this syntax if and when it reaches stage 4.

In the meantime, you can use ESLint with an external parser, like @babel/eslint-parser which already supports this syntax.

[limpid-kzonix]

Hi @mdjermanovic, Thanks for pointing me to the solutions.

I ran into a little babel-parser issue. And to be exact, the issue with eslint/lib/rules/no-unused-vars, only in case of using babel-parser.

I have prepared a minor fix for that one. But I'm worried the problem could be more in babel parser rather than eslint rule itself.

Could you please check the PR, I have attached a little description of the error there
#13592