@putout/plugin-remove-unused-types 
Putout plugin adds ability to find and remove unused types.
Moved to @putout/plugin-typescript
Install
npm i @putout/plugin-remove-unused-types -D
Rule
{
"rules": {
"remove-unused-types": "on"
}
}
Incorrect code example
type n = number;
type s = string;
const x: n = 5;
Correct code Example
type n = number;
const x: n = 5;
License
MIT