standard 14 reports parsing errors for valid public static class fields

[zeke]

What version of this package are you using?

14.3.4

What operating system, Node.js, and npm version?

macOS Catalina, Node.js 12.8.0, npm 6.14.3

What happened?

This is a repeat of #940 where the use of a public static class field:

class ClassWithStaticField {
  static staticField = 'static field'
}

Causes this error:

Parsing error: Unexpected token =

Repros:

• https://runkit.com/zeke/5ecb2dadd71fee001b140d56
• https://github.com/zeke/standard-class-static-props

What did you expect to happen?

I do not expect to see any errors.

Are you willing to submit a pull request to fix this bug?

Perhaps!?

[zeke]

It appears that eslint comments don't work as a workaround for this either:

class AlgoliaIndex {
  static maxRecordLength = 8000 // eslint-disable-line
}

still causes this error:

> standard --fix

standard: Use JavaScript Standard Style (https://standardjs.com)
  /Users/z/git/github/docs/lib/algolia/search-index.js:12:27: Parsing error: Unexpected token =

[pal]

Did you find a work-around @zeke?

[feross]

Static class features is still Stage 3 and it's ESLint policy to only support Stage 4 proposals.

In the meantime, you can enable support with babel-eslint by following the instructions here: https://standardjs.com/#how-do-i-use-experimental-javascript-es-next-features

Also, duplicate of #1478

[balazsorban44]

UPDATE: So according to #1601 (comment) my configuration below is not supported in standard. Ignore the following.

Trying to add support for this Stage 3 proposal.

Tried using the How do I use experimental JavaScript (ES Next) features? section, and added the following to my package.json:

"standard": {
  "parser": "@babel/eslint-parser"
}

Running npx standard file.js reports the following error:

standard: Use JavaScript Standard Style (https://standardjs.com)
/project/file.js:0:0: Parsing error: No Babel config file detected for /project/file.js. Either disable config file checking with requireConfigFile: false, or configure Babel so that it can find the config files.

Tried also adding the config to package.json like the following as per the docs for @babel/eslint-parser:

"standard": {
  "parser": "@babel/eslint-parser",
    "parserOptions": {
      "babelOptions": {
        "configFile": "./config/babel.config.json"
      }
    }
  }
}

[RangerMauve]

I noticed that there's new rules being added to eslint that support this functionality.

eslint/eslint#14591

Would updating the eslint dependency in standard be enough to enable the parsing?

Do we need to wait for all the private rules to be finished before it gets added into standard, or would the partial set that's already complete be enough?

[RangerMauve]

Ah, looks like the new features are in eslint@8.0.0-beta.1, so I'm guessing we'd need to wait for the next stable version to be released.