[valid-typeof] @typescript-eslint/recommended disables valid-typeof but it shouldn't

[karoun]

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have read the FAQ and my problem is not listed.

Repro

{
  "extends": ["plugin:@typescript-eslint/recommended"]
}

typeof window === undefined
typeof window === null

Expected Result

error  Typeof comparisons should be to string literals  valid-typeof

Actual Result

🦗

Additional Info

The @typescript-eslint/recommended ruleset disables the valid-typeof ESLint rule on the basis that it's covered by TypeScript's "This condition will always return 'false'" handling.

However, this is incorrect: TypeScript does not detect this incorrect condition in the case of null and undefined, and so the valid-typeof rule should be re-enabled in the recommended preset.

Versions

package	version
@typescript-eslint/eslint-plugin	4.23.0
@typescript-eslint/parser	4.23.0
TypeScript	4.2.4
ESLint	7.26.0
node	12.13.1

[JounQin]

A related proof #3635

[tanohzana]

I'm working on it!