ESLint rule for spaces in union types in TypeScript

Question

Is there an ESLint rule for TypeScript that allows enforcing using space in the following situation?

// good
let a: string | number = 4;

// bad
let a: string|number = 4;

The only stuff that might be helpful are type-annotation-spacing and space-infix-ops rules but they do not seem to work with union types.

Answer 1

Seems the rule @typescript-eslint/space-infix-ops has been recently (May 2021) updated to handle this.

https://github.com/typescript-eslint/typescript-eslint/issues/51 (Not sure why the issue is still open)

Answer 2

Maybe not what you want, but won't eslint-plugin-prettier do this for you?