eslint-config-standard: Environment key "es2021" is unknown

@bonesoul Are you sure that’s the ESLint that is used then?

Do you see this error on the command line or in eg. Visual Studio Code?

If on command line:

1. Have you ensured that you are running the local eslint and not a globally installed one?
   1. If you run npx eslint --version – then it shows v7.11.0?
   2. If you run eslint --version – does it run? If so, does it also show v7.11.0?

If in Visual Studio Code or similar:

1. Which extension are you using?
2. Which version of that extension?
3. Which version of Visual Studio Code?

same here.

i’m already using eslint 7.11.0;

"eslint": "7.11.0",

You need to update your ESLint then, es2021 was introduced in ESLint version 7.8.0: https://github.com/eslint/eslint/releases/tag/v7.8.0

Also, eslint-config-standard version 15.0.0 states that it requires at least ESLint 7.11.0, so you should be seeing some kind of warning about having wrong peer dependencies: https://github.com/standard/eslint-config-standard/blob/6cd5bd5371189e9c8bda05992644de6e589a7a53/package.json#L51

A friendly suggestion to avoid this in the future:

If you use the install-peerdeps CLI tool to install a package like this, which has many peer dependencies, then it will automatically install the correct peer dependencies for you.

I have run into this problem recently.

ESLint error log

[Error - 12:07:00 PM] ESLint stack trace:
[Error - 12:07:00 PM] Error: .eslintrc.cjs » @chatie/eslint-config » eslint-config-standard:
	Environment key "es2021" is unknown

    at /Users/huan/git/huan/ducks/node_modules/eslint/lib/shared/config-validator.js:169:19
    at Array.forEach (<anonymous>)
    at validateEnvironment (/Users/huan/git/huan/ducks/node_modules/eslint/lib/shared/config-validator.js:163:30)
    at validateConfigArray (/Users/huan/git/huan/ducks/node_modules/eslint/lib/shared/config-validator.js:334:9)
    at CascadingConfigArrayFactory._finalizeConfigArray (/Users/huan/git/huan/ducks/node_modules/eslint/lib/cli-engine/cascading-config-array-factory.js:417:13)
    at CascadingConfigArrayFactory.getConfigArrayForFile (/Users/huan/git/huan/ducks/node_modules/eslint/lib/cli-engine/cascading-config-array-factory.js:271:21)
    at CLIEngine.isPathIgnored (/Users/huan/git/huan/ducks/node_modules/eslint/lib/cli-engine/cli-engine.js:951:18)
    at CLIEngine.executeOnText (/Users/huan/git/huan/ducks/node_modules/eslint/lib/cli-engine/cli-engine.js:868:38)
    at _e.lintText (/Users/huan/.vscode/extensions/dbaeumer.vscode-eslint-2.1.25/server/out/eslintServer.js:1:177327)
    at /Users/huan/.vscode/extensions/dbaeumer.vscode-eslint-2.1.25/server/out/eslintServer.js:1:171074

NPM versions

ducks@0.11.1 /Users/huan/git/huan/ducks
└─┬ @chatie/eslint-config@0.14.1
  ├─┬ @typescript-eslint/eslint-plugin-tslint@4.31.1
  │ ├─┬ @typescript-eslint/experimental-utils@4.31.1
  │ │ ├─┬ eslint-utils@3.0.0
  │ │ │ └── eslint@7.32.0 deduped
  │ │ └── eslint@7.32.0 deduped
  │ └── eslint@7.32.0 deduped
  ├─┬ @typescript-eslint/eslint-plugin@4.31.1
  │ └── eslint@7.32.0 deduped
  ├─┬ @typescript-eslint/parser@4.31.1
  │ └── eslint@7.32.0 deduped
  ├─┬ babel-eslint@10.1.0
  │ └── eslint@7.32.0 deduped
  ├─┬ eslint-config-standard@16.0.3
  │ └── eslint@7.32.0 deduped
  ├─┬ eslint-plugin-import@2.24.2
  │ └── eslint@7.32.0 deduped
  ├─┬ eslint-plugin-node@11.1.0
  │ ├─┬ eslint-plugin-es@3.0.1
  │ │ └── eslint@7.32.0 deduped
  │ └── eslint@7.32.0 deduped
  ├─┬ eslint-plugin-promise@5.1.0
  │ └── eslint@7.32.0 deduped
  ├─┬ eslint-plugin-standard@5.0.0
  │ └── eslint@7.32.0 deduped
  └── eslint@7.32.0

✔ ~/git/huan/ducks [esm ↑·5|✚ 8] 
12:06 $ npx eslint --version
v7.32.0
✔ ~/git/huan/ducks [esm ↑·5|✚ 8] 
12:09 $ npm ls eslint-config-standard
ducks@0.11.1 /Users/huan/git/huan/ducks
└─┬ @chatie/eslint-config@0.14.1
  └── eslint-config-standard@16.0.3

✔ ~/git/huan/ducks [esm ↑·5|✚ 8] 
12:09 $ eslint --version
bash: eslint: command not found
✘-127 ~/git/huan/ducks [esm ↑·5|✚ 8] 
12:09 $ esli^C
✘-INT ~/git/huan/ducks [esm ↑·5|✚ 8] 
12:09 $ npx eslint --version
v7.32.0
✔ ~/git/huan/ducks [esm ↑·5|✚ 8] 
12:09 $ eslint --version
bash: eslint: command not found

Reproducible repo

https://github.com/huan/ducks

BTW: the above error only shows in vscode, but I can run eslint without any problem in command line.

I ran into this as well. Reason was, I had an outdated eslint installed globally (7.6.0) that was picked up by neovim instead of the project wide dependency @ 7.14.0. A npm i -g eslint did it for me.

same here.

This is maybe a longshot, but for future folks: I am working in a monorepo with nested packages, where the base repo had the correct version of eslint, but a child repo had its own version of eslint that was older. So if you have nested repos, double-check (and make sure npx eslint --version says what you think it should!)

For future reference, in my case, it turns out prettier-standard is the culprit. It is way behind standard releases nowadays.

I still ran into this, and I’m using eslint@7.32.0, both locally and globally are the same.

I’ve degraded eslint-config-standard to 14.0.0, it works for me.