prefer-for-of rule false positive

[plantain-00]

Bug Report

• TSLint version: 4.2.0
• TypeScript version: 2.1.4
• Running TSLint via: (please choose one) CLI

TypeScript code being linted

const a = [1, 2];
const b = [2, 3];
for (let i = 0; i < a.length; i++) {
    console.log(a[i] + b[i]);
}

with tslint.json configuration:

{
    "extends": "tslint:latest",
    "rules": {
        "forin": false,
        "interface-name": [
            false
        ],
        "max-line-length": [
            false
        ],
        "no-var-requires": false,
        "no-console": [
            false
        ],
        "no-string-literal": false,
        "no-reference": false,
        "ordered-imports": [
            false
        ],
        "object-literal-sort-keys": false,
        "variable-name": [
            true,
            "ban-keywords"
        ],
        "no-bitwise": false,
        "member-access": false,
        "arrow-parens": false,
        "array-type": [true, "array"],
        "max-classes-per-file": [false]
    }
}

Actual behavior

Expected a 'for-of' loop instead of a 'for' loop with this simple iteration

Expected behavior

No error.
Because the code cannot be transformed to for...of.

[adidahiya]

if you have support for Array.prototype.entries() in your environment, this could work for you:

for (const [i, elem] of a.entries()) {
    console.log(elem + b[i]);
}

but you're right, this looks like a bug in the rule implementation; it probably shouldn't flag that code as a failure.

[nchen63]

I can't reproduce this issue. Can anyone else?

[plantain-00]

@nchen63
Another example closer to my real code:

declare const value1: any;
declare const value2: any;
for (let i = 0; i < (value1 as number[]).length; i++) {
    if ((value1 as number[])[i] === (value2 as number[])[i]) {
    }
}

[nchen63]

@plantain-00 That one reproduces the issue

[plantain-00]

Sorry for initial wrong code, I have no clue how it happened then.
Thanks for fixing this.