Update JS env and remove or update parserOptions.ecmaVersion

[jonaskuske]

Tell us about your environment

• ESLint version: 8.24.0
• eslint-plugin-vue version: 9.5.1
• Node version: 16.14.2

The problem you want to solve.

Currently, eslint-plugin-vue configures both env and parserOptions.ecmaVersion in its base config, with different ECMA versions – 2015 (ES6) and 2020: https://github.com/vuejs/eslint-plugin-vue/blob/467e85fdf29139050d92e61bd7ea217a53af87cb/lib/configs/base.js#L9-L14

The es6 env means that globals that were added after 2015 can't be used without errors, like BigInt, globalThis or WeakRef.

parser.ecmaVersion: 2020 means that parsing breaks on features like dynamic import or nullish assignments.

env automatically sets the version for the parser, but since this plugin explicitly configures the parser version in addition to env, that doesn't work anymore when users change the env in their config. So if users specify es2022: true as their env, the parser will not automatically switch to 2022 syntax as described in the ESLint docs but keep its 2020 config and continue to break on newer syntax.

Your take on the correct solution to problem.

1. Bump the version for the supported JS environment to es2022 (latest). Or, if the outdated version config for the parser is intentional for compat, set the environment to es2020 to align it with the parser version.

2. Either remove the parserOptions.ecmaVersion setting so it is automatically inferred from env, or set it to latest so the parser won't get in the way.

Additional context

Here's a repro repo: https://github.com/jonaskuske/vue-eslint-repro