PregReplaceEModifierRector should work if $pattern is an array

[derflocki]

Bug Report

Subject	Details
Rector version	v0.7.7
Installed as	composer dependency

The PregReplaceEModifierRector throws Exception if $pattern is an array.

Minimal PHP Code Causing Issue

https://getrector.org/demo/dfc1a6b3-aac1-478f-a8c4-f2d4fb63e98c

Expected Behaviour

It should work, or at least not throw an Exception but rather indicate, that manual intervention might be necessary.

[TomasVotruba]

What's the expected change?

[derflocki]

Given, that all items in $pattern have the /e modifier, the result would be the same as if it was a string:

preg_replace_callback($pattern, $callback, ...);

But since, only one of them COULD match producing the correct output would be tricky.

I have also encounterd that it also fails if $pattern is not "obviously" a string (is composed of function calls):

https://getrector.org/demo/22f5b2b4-0823-48cc-8ce5-8a6b52fa2487

[TomasVotruba]

I've covered the concat case.

If you find a replacement for https://getrector.org/demo/dfc1a6b3-aac1-478f-a8c4-f2d4fb63e98c, send PR with failing fixture. Just copy one of: https://github.com/rectorphp/rector/tree/master/rules/php55/tests/Rector/FuncCall/PregReplaceEModifierRector/Fixture and add

before
-----
after

code in them.