[Naming] Skip RenameForeachValueVariableToMatchExprVariableRector on empty singular value name result (#5978)

rules-tests/Naming/Rector/Foreach_/RenameForeachValueVariableToMatchExprVariableRector/Fixture/skip_empty_singular_value.php.inc

@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\Naming\Rector\Foreach_\RenameForeachValueVariableToMatchExprVariableRector\Fixture;
+
+class SkipEmptySingularValue
+{
+    public function run()
+    {
+        foreach ($_FOO as $file) {
+
+        }
+    }
+}

rules/Naming/ExpectedNameResolver/InflectorSingularResolver.php

@@ -64,6 +64,10 @@ final class InflectorSingularResolver
             $singularValueVarName .= $this->inflector->singularize($camelCase['camelcase']);
         }
 
+        if ($singularValueVarName === '') {
+            return $currentName;
+        }
+
         $singularValueVarName = $singularValueVarName === $currentName
             ? self::SINGLE . ucfirst($singularValueVarName)
             : $singularValueVarName;

rules/Naming/Rector/Foreach_/RenameForeachValueVariableToMatchExprVariableRector.php

@@ -99,6 +99,10 @@ CODE_SAMPLE
         }
 
         $singularValueVarName = $this->inflectorSingularResolver->resolve($exprName);
+        if ($singularValueVarName === $exprName) {
+            return null;
+        }
+
         if ($this->shouldSkip($valueVarName, $singularValueVarName, $node)) {
             return null;
         }