Environment

Playground

What parser are you using?

@typescript-eslint/parser

What did you do?

{
  "extends": [
    "eslint:all",
    "plugin:@typescript-eslint/all"
  ],
  "rules": {
  }
}

const foo = (two: string): void => {
  "use strict";
  
  // eslint-disable-next-line @typescript-eslint/init-declarations
  let one: string | undefined;

  if (one === two) {
    // Noop
  }
}

foo("");

What did you expect to happen?

In this code snippet, let one; is read but never assigned. I would expect some rule to flag it – the most appropriate one seems like it would be prefer-const.

What actually happened?

prefer-const does not complain about this code. (Maybe because const one; is not allowed syntax?)

Link to Minimal Reproducible Example

Playground

Participation

• I am willing to submit a pull request for this issue.

Additional comments

Here is a typescript-eslint version of the playground.

If prefer-const is not the right rule to flag this error, then what is?