False-positive in prefer-const and array-destructuring

[danez]

Tell us about your environment

• ESLint Version: 3.18.0
• Node Version: 6.10.0
• npm Version: 4.4.4

What parser (default, Babel-ESLint, etc.) are you using?
default

Please show your full configuration:

{
  "ecmaVersion": 7,
  "rules": [
    "prefer-const"
  ]
}

What did you do? Please include the actual source code causing the issue.

let predicate;
[typeNode.returnType, predicate] = foo();

What did you expect to happen?

No error

What actually happened? Please include the actual, raw output from ESLint.

2:23 - 'predicate' is never reassigned. Use 'const' instead. (prefer-const)

The rule should consider that it is not possible to actually make predicate a const here.

[not-an-aardvark]

Thanks for the report. I was able to reproduce this issue.

[VictorHom]

I would like to look into this issue as well if no one is working on this :)

[not-an-aardvark]

Thanks @VictorHom!

[pvdlg]

If that can help, the same happen with Object destructuring:

let a;
const b = {};

({a, c: b.c} = func());

4:3 - 'a' is never reassigned. Use 'const' instead. (prefer-const)

[nzakas]

This seems like a pretty significant bug. I'd like to take a stab at fixing this.