Fix VariableInDoubleQuotedString sniff wrapping property/array access

The sniff incorrectly fixed "$this->key" to "{$this}->key" instead of
"{$this->key}" because the regex only matched bare variable names. Expand
the regex to also capture ->property and [index] suffixes, matching PHP's
simple string interpolation rules.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

MO4/Sniffs/Strings/VariableInDoubleQuotedStringSniff.php

@@ -60,7 +60,7 @@ public function register(): array
      */
     public function process(File $phpcsFile, $stackPtr): void
     {
-        $varRegExp = '/\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/';
+        $varRegExp = '/\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*(?:\->[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*|\[[^\]]*\])?/';
 
         $tokens  = $phpcsFile->getTokens();
         $content = $tokens[$stackPtr]['content'];

MO4/Tests/Strings/VariableInDoubleQuotedStringUnitTest.fail.inc

@@ -9,3 +9,5 @@ $d = "blafasel $_a";
 $f = "100$missing needed";
 $g = "foo {$a} bar $b";
 $h = " foo } bar { foo $a";
+$i = "value is $this->key ok";
+$j = "value is $arr[0] ok";

MO4/Tests/Strings/VariableInDoubleQuotedStringUnitTest.fail.inc.fixed

@@ -9,3 +9,5 @@ $d = "blafasel {$_a}";
 $f = "100{$missing} needed";
 $g = "foo {$a} bar {$b}";
 $h = " foo } bar { foo {$a}";
+$i = "value is {$this->key} ok";
+$j = "value is {$arr[0]} ok";

MO4/Tests/Strings/VariableInDoubleQuotedStringUnitTest.pass.inc

@@ -22,3 +22,5 @@ $o = "{$a['foo'][$b[0]]}";
 $p = "{$a[$b->foo($c['foo'][$d[0]])]}";
 $p = "{$good[$fail]}";
 $q = "{$prefix}/{$this->resolveName($id)}";
+$r = "{$this->key}";
+$s = "{$arr[0]}";

MO4/Tests/Strings/VariableInDoubleQuotedStringUnitTest.php

@@ -44,6 +44,8 @@ class VariableInDoubleQuotedStringUnitTest extends AbstractMo4SniffUnitTest
             9  => 1,
             10 => 1,
             11 => 1,
+            12 => 1,
+            13 => 1,
         ],
     ];
 }