PHP 8.4 | Tokenizer/PHP: allow for anon class dereferencing

As of PHP 8.4, new expressions can be dereferenced without needing parentheses wrappers, as long as they have the parentheses for the constructor arguments.
```php
echo new MyClass()->property;
echo new $myClass(['value'])[0];
```

Additionally, new expressions involving anonymous classes can also be dereferenced directly and these do not have the constructor argument parentheses requirement.
```php
echo new class { public $property = 'property'; }->property;
echo new class (['value']) extends ArrayObject {}[0];
```

For the most part, this has no impact on the PHPCS tokenizer layer, however, dereferencing the result of a new anonymous class expression using array access runs into trouble with the short array retokenization.
I.e. the square brackets in the below example were tokenized as `T_OPEN|CLOSE_SHORT_ARRAY`, while they should be tokenized as `T_OPEN|CLOSE_SQUARE_BRACKET`.
```php
echo new class {}[0];
```

Fixed now. Includes tests safeguarding the fix.

Refs:
* https://wiki.php.net/rfc/new_without_parentheses
* php/php-src 13029

Author: jrfnl

src/Tokenizers/PHP.php

@@ -3127,6 +3127,29 @@ protected function processAdditional()
                 $allowed     += Tokens::$magicConstants;
 
                 for ($x = ($i - 1); $x >= 0; $x--) {
+                    // Allow for PHP 8.4 anon class dereferencing without wrapping parentheses.
+                    // Note: the T_CLASS token has not yet been retokenized to T_ANON_CLASS!
+                    if ($this->tokens[$x]['code'] === T_CLOSE_CURLY_BRACKET
+                        && isset($this->tokens[$x]['scope_condition']) === true
+                        && $this->tokens[$this->tokens[$x]['scope_condition']]['code'] === T_CLASS
+                    ) {
+                        // Now, make sure it is an anonymous class and not a normal class.
+                        for ($y = ($this->tokens[$x]['scope_condition'] + 1); $y < $numTokens; $y++) {
+                            if (isset(Tokens::$emptyTokens[$this->tokens[$y]['code']]) === false) {
+                                break;
+                            }
+                        }
+
+                        // Use the same check as used for the anon class retokenization.
+                        if ($this->tokens[$y]['code'] === T_OPEN_PARENTHESIS
+                            || $this->tokens[$y]['code'] === T_OPEN_CURLY_BRACKET
+                            || $this->tokens[$y]['code'] === T_EXTENDS
+                            || $this->tokens[$y]['code'] === T_IMPLEMENTS
+                        ) {
+                            break;
+                        }
+                    }
+
                     // If we hit a scope opener, the statement has ended
                     // without finding anything, so it's probably an array
                     // using PHP 7.1 short list syntax.

tests/Core/Tokenizers/PHP/ShortArrayTest.inc

@@ -68,6 +68,19 @@ $var = $obj?->function_call()[$x];
 /* testInterpolatedStringDereferencing */
 $var = "PHP{$rocks}"[1];
 
+/* testNewAnonClassNoParenthesesExpressionDereferencing */
+$a = new class {}[0];
+
+$a = new class (['value'])
+    /* testNewAnonClassParenthesesExpressionDereferencing */
+    {}[0];
+
+/* testNewAnonClassExtendsExpressionDereferencing */
+$a = new readonly class extends ArrayObject {}[0];
+
+/* testNewAnonClassImplementsExpressionDereferencing */
+$a = new class implements ArrayAccess {}[0];
+
 /*
  * Short array brackets.
  */
@@ -106,6 +119,10 @@ if ( true ) :
     [ $a ] = [ 'hi' ];
 endif;
 
+class Foo extends ArrayObject {}
+/* testShortListDeclarationAfterClassDeclaration */
+[$a] = ['hi'];
+
 /* testLiveCoding */
 // Intentional parse error. This has to be the last test in the file.
 $array = [

tests/Core/Tokenizers/PHP/ShortArrayTest.php

@@ -55,29 +55,33 @@ public function testSquareBrackets($testMarker)
     public static function dataSquareBrackets()
     {
         return [
-            'array access 1'                                => ['/* testArrayAccess1 */'],
-            'array access 2'                                => ['/* testArrayAccess2 */'],
-            'array assignment'                              => ['/* testArrayAssignment */'],
-            'function call dereferencing'                   => ['/* testFunctionCallDereferencing */'],
-            'method call dereferencing'                     => ['/* testMethodCallDereferencing */'],
-            'static method call dereferencing'              => ['/* testStaticMethodCallDereferencing */'],
-            'property dereferencing'                        => ['/* testPropertyDereferencing */'],
-            'property dereferencing with inaccessable name' => ['/* testPropertyDereferencingWithInaccessibleName */'],
-            'static property dereferencing'                 => ['/* testStaticPropertyDereferencing */'],
-            'string dereferencing single quotes'            => ['/* testStringDereferencing */'],
-            'string dereferencing double quotes'            => ['/* testStringDereferencingDoubleQuoted */'],
-            'global constant dereferencing'                 => ['/* testConstantDereferencing */'],
-            'class constant dereferencing'                  => ['/* testClassConstantDereferencing */'],
-            'magic constant dereferencing'                  => ['/* testMagicConstantDereferencing */'],
-            'array access with curly braces'                => ['/* testArrayAccessCurlyBraces */'],
-            'array literal dereferencing'                   => ['/* testArrayLiteralDereferencing */'],
-            'short array literal dereferencing'             => ['/* testShortArrayLiteralDereferencing */'],
-            'class member dereferencing on instantiation 1' => ['/* testClassMemberDereferencingOnInstantiation1 */'],
-            'class member dereferencing on instantiation 2' => ['/* testClassMemberDereferencingOnInstantiation2 */'],
-            'class member dereferencing on clone'           => ['/* testClassMemberDereferencingOnClone */'],
-            'nullsafe method call dereferencing'            => ['/* testNullsafeMethodCallDereferencing */'],
-            'interpolated string dereferencing'             => ['/* testInterpolatedStringDereferencing */'],
-            'live coding'                                   => ['/* testLiveCoding */'],
+            'array access 1'                                 => ['/* testArrayAccess1 */'],
+            'array access 2'                                 => ['/* testArrayAccess2 */'],
+            'array assignment'                               => ['/* testArrayAssignment */'],
+            'function call dereferencing'                    => ['/* testFunctionCallDereferencing */'],
+            'method call dereferencing'                      => ['/* testMethodCallDereferencing */'],
+            'static method call dereferencing'               => ['/* testStaticMethodCallDereferencing */'],
+            'property dereferencing'                         => ['/* testPropertyDereferencing */'],
+            'property dereferencing with inaccessable name'  => ['/* testPropertyDereferencingWithInaccessibleName */'],
+            'static property dereferencing'                  => ['/* testStaticPropertyDereferencing */'],
+            'string dereferencing single quotes'             => ['/* testStringDereferencing */'],
+            'string dereferencing double quotes'             => ['/* testStringDereferencingDoubleQuoted */'],
+            'global constant dereferencing'                  => ['/* testConstantDereferencing */'],
+            'class constant dereferencing'                   => ['/* testClassConstantDereferencing */'],
+            'magic constant dereferencing'                   => ['/* testMagicConstantDereferencing */'],
+            'array access with curly braces'                 => ['/* testArrayAccessCurlyBraces */'],
+            'array literal dereferencing'                    => ['/* testArrayLiteralDereferencing */'],
+            'short array literal dereferencing'              => ['/* testShortArrayLiteralDereferencing */'],
+            'class member dereferencing on instantiation 1'  => ['/* testClassMemberDereferencingOnInstantiation1 */'],
+            'class member dereferencing on instantiation 2'  => ['/* testClassMemberDereferencingOnInstantiation2 */'],
+            'class member dereferencing on clone'            => ['/* testClassMemberDereferencingOnClone */'],
+            'nullsafe method call dereferencing'             => ['/* testNullsafeMethodCallDereferencing */'],
+            'interpolated string dereferencing'              => ['/* testInterpolatedStringDereferencing */'],
+            'new anonymous class expression dereferencing 1' => ['/* testNewAnonClassNoParenthesesExpressionDereferencing */'],
+            'new anonymous class expression dereferencing 2' => ['/* testNewAnonClassParenthesesExpressionDereferencing */'],
+            'new anonymous class expression dereferencing 3' => ['/* testNewAnonClassExtendsExpressionDereferencing */'],
+            'new anonymous class expression dereferencing 4' => ['/* testNewAnonClassImplementsExpressionDereferencing */'],
+            'live coding'                                    => ['/* testLiveCoding */'],
         ];
 
     }//end dataSquareBrackets()
@@ -133,6 +137,7 @@ public static function dataShortArrays()
             'short list after braced control structure'      => ['/* testShortListDeclarationAfterBracedControlStructure */'],
             'short list after non-braced control structure'  => ['/* testShortListDeclarationAfterNonBracedControlStructure */'],
             'short list after alternative control structure' => ['/* testShortListDeclarationAfterAlternativeControlStructure */'],
+            'short list after class declaration'             => ['/* testShortListDeclarationAfterClassDeclaration */'],
         ];
 
     }//end dataShortArrays()