Add Support for Top-level await

[NemoStein]

Today Top-level await reached Stage 4.
This brings new depth to async modules, and I'm looking forward to seeing it implemented in ESLint in the near future.

• Ecma262 update: Normative: Top-level Await tc39/ecma262#2408
• ESTree update: n/a
• Acorn update: Change allowAwaitOutsideFunction to be enabled by default when ecmaVersion >= 2022 acornjs/acorn#1040
• eslint-visitor-keys
• espree update: Update: Support top-level await and regexp match indices espree#505
• eslint-scope update:
• eslint update:

[janosh]

For reference, the relevant comment in the tc39 proposal.

[ljharb]

(The canonical source of truth is here: tc39/proposals@99fa42a)

[nzakas]

Thanks for opening this. We can definitely start implanting it and would love some help to get started.

[ota-meshi]

I opened a pull request in acorn.
acornjs/acorn#1040

[Nantris]

Related (but old and outdated) #13178

[nimit2801]

What is the status of this feature, I want to use eslint with my project and want a way to wave of the error?
Can someone suggest to me what should I do from the following

1. Add rules or something to ignore this error if yes any examples
2. If this is supported what things should I mention in `.eslintrc.json` to use this feature

Question: what version of ecma does top-level await joins in?
Thank You

[saschanaz]

Probably blocked by #14591?

[nzakas]

Yup. Support will be released in v8.0.0. We are finishing up that work now.

[ktx-mega]

Do you have an idea of the release date ?

[nzakas]

Nothing firm. We will likely release a beta within the next two weeks and the final version will depend on the feedback we get during the beta.

[joshunger]

Happy afternoon (or morning)! Will this fix Parsing error: Can not use keyword 'await' outside an async function and what specific 8.0 beta version? I just tried v8.0.0-beta.1 with an mjs file and it did not work. Thanks.

[nzakas]

@joshunger it should. Be sure you have ecmaVersion set to 2022 and sourceType set to module. If you’re still having trouble, please stop by the chat.

[joshunger]

@nzakas thanks for the help I missed the ecmaVersion. It is working great!

[AndreiSoroka]

Hi!

> eslint . --ext .mjs --fix


Oops! Something went wrong! :(

ESLint: 8.0.0-beta.1

Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './lib/util/glob-util' is not defined by "exports" in /Users/andreisoroka/git/other/faststartservice/node_modules/eslint/package.json
    at throwExportsNotFound (internal/modules/esm/resolve.js:285:9)
    at packageExportsResolve (internal/modules/esm/resolve.js:508:3)
    at resolveExports (internal/modules/cjs/loader.js:450:36)
    at Function.Module._findPath (internal/modules/cjs/loader.js:490:31)
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:888:27)
    at Function.Module._load (internal/modules/cjs/loader.js:746:27)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (/Users/andreisoroka/git/other/faststartservice/node_modules/v8-compile-cache/v8-compile-cache.js:159:20)
    at Object.<anonymous> (/Users/andreisoroka/git/other/faststartservice/node_modules/eslint-plugin-import/lib/rules/no-unused-modules.js:43:34)
    at Module._compile (/Users/andreisoroka/git/other/faststartservice/node_modules/v8-compile-cache/v8-compile-cache.js:192:30)
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! fuststartservice@0.0.0 lint:fix: `eslint . --ext .mjs --fix`
npm ERR! Exit status 2
npm ERR! 
npm ERR! Failed at the fuststartservice@0.0.0 lint:fix script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

package.json

{
  "scripts": {
    "lint": "eslint . --ext .mjs",
    "lint:fix": "eslint . --ext .mjs --fix"
  },
  "devDependencies": {
    // "eslint": "^7.32.0", // was
    "eslint": "^8.0.0-beta.1",
    "eslint-config-airbnb-base": "^14.2.1",
    "eslint-plugin-import": "^2.24.2"
  }
}

{
  "env": {
    // "es2021": true, (and with 2021 don't work)
    "es2022": true,
    "node": true
  },
  "extends": [
    "airbnb-base"
  ],
  "parserOptions": {
    // "ecmaVersion": 12, // was
    "ecmaVersion": 2022,
    "sourceType": "module"
  },
  "settings": {
    "import/resolver": {
      "node": {
        "extensions": [
          ".js",
          ".mjs"
        ]
      }
    }
  },
  "rules": {
    "no-console": "off",
    "no-underscore-dangle": "off",
    "import/extensions": [
      "error",
      "always"
    ]
  }
}

[mdjermanovic]

Hi @AndreiSoroka!

ESLint: 8.0.0-beta.1

Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './lib/util/glob-util' is not defined by "exports" in /Users/andreisoroka/git/other/faststartservice/node_modules/eslint/package.json
    at throwExportsNotFound (internal/modules/esm/resolve.js:285:9)
    at packageExportsResolve (internal/modules/esm/resolve.js:508:3)
    at resolveExports (internal/modules/cjs/loader.js:450:36)
    at Function.Module._findPath (internal/modules/cjs/loader.js:490:31)
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:888:27)
    at Function.Module._load (internal/modules/cjs/loader.js:746:27)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (/Users/andreisoroka/git/other/faststartservice/node_modules/v8-compile-cache/v8-compile-cache.js:159:20)
    at Object.<anonymous> (/Users/andreisoroka/git/other/faststartservice/node_modules/eslint-plugin-import/lib/rules/no-unused-modules.js:43:34)

This is a problem in eslint-plugin-import, it's using some internal APIs that have been removed in ESLint 8.

Can you please report this problem to https://github.com/import-js/eslint-plugin-import ?

Thanks for testing ESLint prereleases and let us know if you find any other problems! Just please open separate issue(s) so we could track them, this one is only about adding support for top-level await.

[AndreiSoroka]

Thanks! I check issues and find import-js/eslint-plugin-import#2211

[AndreiSoroka]

FYI: @ljharb

[ljharb]

I’m aware; most of the ecosystem doesn’t support eslint 8 yet, which is fine since it’s not actually out yet.

[nzakas]

Please open new issues if you find problems with ESLint 8 functionality.