False positive for no-shadowed-variable with multiple index definitions

[JoshuaKGoldberg]

Bug Report

• TSLint version: 3.8.1
• TypeScript version: 1.8.10
• Running TSLint via: gulp-tslint

TypeScript code being linted

interface IFoo {
    [i: string]: any;
    [i: number]: any;
}

with tslint.json:

{
    "rules": {
        "no-shadowed-variable": true
    }
}

Actual behavior

(no-shadowed-variable) file.ts[6, 6]: shadowed variable: 'i'

Expected behavior

This should be fine, yes?

[ChrisMBarr]

why not just write it like this?

interface IFoo {
    [i: string|number]: any;
}

[JoshuaKGoldberg]

@ChrisMBarr Not allowed before TS 1.5: microsoft/TypeScript#1715

Otherwise the bug still holds for the following:

interface IFoo {
    [i: string]: boolean;
    [i: number]: string | any;
}