ExplicitStringVariableFixer - wrong behavior for arrays

[gharlan]

• before running PHP CS Fixer (no changes):

<?php $a = "My name is $array[MY_CONSTANT] !";

• with unexpected changes applied when running PHP CS Fixer:

<?php $a = "My name is {$array[MY_CONSTANT]} !";

• with the changes you expected instead:

<?php $a = "My name is {$array['MY_CONSTANT']} !";

It is a test case from ExplicitStringVariableFixer: https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/1c9553ac16b1d10ea891c6f739aa9215d16de024/tests/Fixer/StringNotation/ExplicitStringVariableFixerTest.php#L117-L118

But it is wrong, MY_CONSTANT is not a constant in that case (see #3913), so it needs quotes in the explicit style.

[dmvdbrugge]

When I saw it, this felt off, but the presence of that testcase convinced me it was the correct behaviour 😞 thanks for confirming my doubts and fixing it 😄👍