Xo: Cannot disable `@typescript-eslint/consistent-indexed-object-style` within `overrides:` section of package.json

[papb]

Steps to reproduce:

1. mkdir temp && cd temp && npm init -y
2. npm i -D xo typescript

3. Create file a.ts:

   export type T = {
   [key: string]: number;
   };
   

4. npx xo

5. Confirm that the @typescript-eslint/consistent-indexed-object-style is reported as expected

6. Disable the rule from an overrides option in package.json:

   {
   "xo": {
     "rules": {
       "no-await-in-loop": "off"
     },
     "overrides": {
       "files": "**/*.ts",
       "rules": {
         "@typescript-eslint/consistent-indexed-object-style": "off"
       }
     }
   }
   }
   

7. npx xo

8. Observe that the error with @typescript-eslint/consistent-indexed-object-style is still reported.

9. As a sanity check move the "@typescript-eslint/consistent-indexed-object-style": "off" setting outside the "overrides" option:

   {
   "xo": {
     "rules": {
       "no-await-in-loop": "off",
       "@typescript-eslint/consistent-indexed-object-style": "off"
     }
   }
   }
   

... Now it works as is should... But why doesn't it work within the "overrides" option?

[sindresorhus]

overrides accepts an array of objects, not just an object.

We should definitely have better validation for this though and throw an error on an incorrect type. PR welcome for that.