Extended configuration does not apply to JS files

[deskoh]

Feature request

Currently using using a tslint rules that extends tslint-config-airbnb. However, the rules does not seem to apply to JS files after setting "jsRules" property set to true. The documentation also did not specify whether this is the intended behaviour.

Example tslint.json file:

{
  "defaultSeverity": "error",
  "extends": [
    "tslint-config-airbnb"
  ],
  "jsRules": true
}

function test() {
  // No lint errors for `prefer-const` rule even though it is defined in `tslint-config-airbnb`.
  let x = 1;
}

The prefer-const rule need to be added explicitly:

{
  "defaultSeverity": "error",
  "extends": [
    "tslint-config-airbnb"
  ],
  "jsRules": {
    "prefer-const": true,
  }
}

Any solution for the extended rules to also apply to JS files?

[JoshuaKGoldberg]

👋 @deskoh, is this a duplicate of #4513?

[deskoh]

Slightly different. Currently using tsc 5.13.1.

tsconfig.json has "allowJs" set to true, running tslint -p . for the following tslint.json has different results:

// Does not flag prefer-const errors in JS files
{
    "defaultSeverity": "error",
    "extends": [
        "tslint:recommended"
    ],
    "jsRules": true,
    "rules": {},
    "rulesDirectory": []
}

// Flag prefer-const errors in JS files
{
    "defaultSeverity": "error",
    "extends": [
        "tslint:recommended"
    ],
    "jsRules": {
        "prefer-const": true
    },
    "rules": {},
    "rulesDirectory": []
}

[JoshuaKGoldberg]

💀 It's time! 💀

TSLint is being deprecated and no longer accepting pull requests for major new changes or features. See #4534. 😱

If you'd like to see this change implemented, you have two choices:

• Recommended: Check if this is available in ESLint + typescript-eslint ✅
• Not Recommended: Fork TSLint locally 🤷‍♂️

👋 It was a pleasure open sourcing with you!

If you believe this message was posted here in error, please comment so we can re-open the issue!

[JoshuaKGoldberg]

🤖 Beep boop! 👉 TSLint is deprecated 👈 (#4534) and you should switch to typescript-eslint! 🤖

🔒 This issue is being locked to prevent further unnecessary discussions. Thank you! 👋