Linter fails to parse public class fields

[twity1337]

Describe the problem and steps to reproduce it:

We developed an Thunderbird addon using modern ES6 modules, as described here https://developer.thunderbird.net/add-ons/mailextensions#webextension-scripts

Unfortunately after months of developing the addon, we were not able to upload it on the AMO.
Linter reports syntax errors in two of our files. It seems, it does not understand all language features of ES6.

The addon works quite fine in current version of Thunderbird (version 78.12.0, 64-bit). So I can't understand, why the validation process is blocking the submission.

What happened?

Uploading the addon is not possible, because the linter cannot parse our addon code (a glimpse of the affected file is given below). Instead the following syntax errors are thrown:

JavaScript syntax error - Error: There is a JavaScript syntax error in your code; validation cannot continue on this file.
chrome/content/lib/db/DatabaseManager.js line 1 column 1

JavaScript syntax error - Error: There is a JavaScript syntax error in your code; validation cannot continue on this file.
chrome/content/lib/repository/ConversationRepository.js line 1 column 1

I think it is noteworthy, that only 2 of our files are reported. We have more files with ES6 features in our addon, but those are not mentioned in the validation report.

What did you expect to happen?

Linter should understand export and import statements and class members defined in class scope.

Anything else we should know?

DatabaseManager.js, Line 1 - 10

export class DatabaseManager {
  __dbConnection
  __dbName

  constructor (name) {
    console.assert(window.indexedDB !== undefined)
    this.__dbConnection = null
    this.__dbName = name
    this.__objectStoreInUse = null
  }
// ....

ConversationRepository.js, Line 1-20

import { DatabaseManager } from '../db/DatabaseManager.js'

export class ConversationRepository {
  __dbManager
  tableName = 'conversation'

  constructor () {
    let ths = this
    this.__dbManager = new DatabaseManager('myname')
    this.__dbManager.initializeDatabase(function (connection, oldVersion, newVersion) {
      if (oldVersion < 1) {
        connection.createObjectStore(ths.tableName, {
          keyPath: 'email',
          autoIncrement: false
        })
      }
    })
    this.__dbManager.useObjectStore(this.tableName)
  }

[Sancus]

addons-linter likely needs to be on a newer version, I can do that on Monday.

[Sancus]

Try submitting your add-on again please.

[twity1337]

Try submitting your add-on again please.

After resubmitting I get the following errors instead:
chrome/content/lib/db/DatabaseManager.js line 2 column 1:

JavaScript syntax error (Parsing as module error: Unexpected token __dbName at line: 3 and column: 3) (Parsing as script error: 'import' and 'export' may appear only with 'sourceType: module' at line: 2 and column: 1)

chrome/content/lib/repository/ConversationRepository.js line 1 column 1:

JavaScript syntax error (Parsing as module error: Unexpected token tableName at line: 5 and column: 3) (Parsing as script error: 'import' and 'export' may appear only with 'sourceType: module' at line: 1 and column: 1)

These errors are solved after removing the public class fields in the two files. Submission is no longer blocked.

After submitting the addon I'll post the addon name here, so further debugging can proceed.

[twity1337]

Okay, I now managed to submit the addon for review.
If you want to check the validation for the addon, check this out: https://addons.thunderbird.net/en-US/thunderbird/addon/smartcompose/

[Sancus]

OK, so the underlying issue here is that eslint does not support public class fields yet, and therefore addons-linter does not, see: mozilla/addons-linter#3836

We cannot resolve this until those upstream issues are fixed, sorry.

[jobisoft]

The AMO bug mentioned a dependency on a ESLint bug, which seems to be fixed now:
eslint/eslint#14343

Does that mean this issue can move forward?

[lieser]

Any update on this? Like @jobisoft mentioned this works since ESLint 8,.0.0 (https://eslint.org/blog/2021/10/eslint-v8.0.0-released).
Also seems to be fixed upstream (mozilla/addons-linter#3062).

This is currently preventing me to upload a new release, since I started to use static fields in classes.
Could of course revert the usage of static fields, but would really like to avoid that.

[Sancus]

Thanks for the reminder, I've updated the linter and deployed the change, so this should work now. Let me know if it doesn't.

ef373a3

[lieser]

Thanks a lot for the quick fix. Can confirm that uploading to ATN worked now.