Let variable usage is not detected

[capaj]

I have this code:

let clarke

test('lala', (t) => {
  clarke = 1
})

When I run standard.js v 7.1.2 I get:

> standard

standard: Use JavaScript Standard Style (http://standardjs.com) 
  /home/capaj/git_projects/mobservable-db/test/queries.spec.js:9:5: 'clarke' is defined but never used

I do not think this is true.
When I change let to var it works and lints just fine.

[feross]

Try this:

let clarke

test('lala', (t) => {
  clarke = 1
  console.log(clarke)
})

clarke is not used if you're just setting it, but never reading it's value.