feat: apply no-var, prefer-const, prefer-reset-params, `prefer-…

…spread` globally

recommended.js

@@ -9,7 +9,23 @@ module.exports = {
 
   rules: {
     // this rule, if on, would require explicit return type on the `render` function
-    '@typescript-eslint/explicit-function-return-type': 'off'
+    '@typescript-eslint/explicit-function-return-type': 'off',
+
+    // The following rules are enabled in an `overrides` field in the
+    // `@typescript-eslint/recommended` ruleset, only turned on for TypeScript source modules
+    // <https://github.com/typescript-eslint/typescript-eslint/blob/cb2d44650d27d8b917e8ce19423245b834db29d2/packages/eslint-plugin/src/configs/eslint-recommended.ts#L27-L30>
+
+    // But as ESLint cannot precisely target `<script lang="ts">` blocks and skip normal `<script>`s,
+    // no TypeScript code in `.vue` files would be checked against these rules.
+
+    // So we now enable them globally.
+    // That would also check plain JavaScript files, which diverges a little from
+    // the original intention of the `@typescript-eslint/recommended` rulset.
+    // But it should be mostly fine.
+    'no-var': 'error', // ts transpiles let/const to var, so no need for vars any more
+    'prefer-const': 'error', // ts provides better types with const
+    'prefer-rest-params': 'error', // ts provides better types with rest args over arguments
+    'prefer-spread': 'error', // ts transpiles spread to apply, so no need for manual apply
   },
 
   overrides: [