Incorrect Behaviour of DisallowedEmptyRuleFixerRector

[mkrauser]

Bug Report

Subject	Details
Rector version	0.17.1

if empty(...) is called for an string-element of an array, the resulting code does not check if the array-key actually exists.

Minimal PHP Code Causing Issue

$parts = parse_url($url);

if (!empty($parts['host'])) {
// is replaced with 
if ($parts['host'] !== '') {

// but the host-key might not be set

https://getrector.com/demo/5df3320d-26b9-47a6-a4ee-7910f747bb9c

Expected Behaviour

I guess adding an additional isset(...)-check would fix this.

[TomasVotruba]

Thank you for your report and demo link!

We'll need a failing test case in a pull-request, so we have it covered in Rector.
You can click "Create a Test" button at demo page.

[scyzoryck]

It looks like more like an issue with return type from parse_url. If we would use key that is not defined no changes will be done.
https://getrector.com/demo/020a71f8-7ecc-46ea-8656-11c7c2e04a54

[TomasVotruba]

Hi, thanks for reporting. I'm looking into this 👍