Unused var error missing when using es6 modules

[dominicbarnes]

It appears that when you use ES6 modules to export a function, the no-unused-var rule does not run properly on those function arguments. (vars declared in the function body still lint correctly)

function fn1({ a, b }) {
  console.log(a);
}

fn1();

export function fn2({ x, y }) {
  console.log(x);
}

fn2();

Given the following config:

{
  "env": {
    "es6": true
  },
  "ecmaFeatures": {
    "modules": true
  },
  "rules": {
    "no-unused-vars": 2
  }
}

When I run this in the CLI:

$ eslint --reset test.js

test.js
  2:18  error  b is defined but never used  no-unused-vars

✖ 1 problem (1 error, 0 warnings)

Notice that fn1 gets linted correctly, but fn2 does not report the unused y var.

[gyandeeps]

What version of eslint are you using?

[dominicbarnes]

The latest :)

$ eslint --version
v0.22.1

[nzakas]

Why is this a bug? b is never used in your example?

[nzakas]

Oh I see, it's missing y.

Are you using Babel-eslint?

[dominicbarnes]

Nah, I'm just using eslint core.

[nzakas]

Thanks. We should double check that escope is doing the right thing here.

[yangit]

export default (a, b)=> {
  console.log(a);
};

this code still yields no errors.
Version is eslint 1.6.1
Settings as mentioned above

{
  "env": {
    "es6": true
  },
  "ecmaFeatures": {
    "modules": true
  },
  "rules": {
    "no-unused-vars": 2
  }
}

Expected output is to get a no-unused-vars error for b variable.

[ilyavolodin]

@yangit Could you open a new issues?

[yangit]

Done #4047