[code-quality] Skip ctor to setup in ConstructClassMethodToSetUpTestCaseRector for non-test classes, e.g. helpers

rules-tests/CodeQuality/Rector/Class_/ConstructClassMethodToSetUpTestCaseRector/Fixture/skip_non_test_but_helper.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\ConstructClassMethodToSetUpTestCaseRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SkipNonTestButHelper extends TestCase
+{
+    private $someValue;
+
+    public function __construct()
+    {
+        $this->someValue = 1000;
+    }
+}

rules/CodeQuality/Rector/Class_/ConstructClassMethodToSetUpTestCaseRector.php

@@ -101,12 +101,12 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
-        $constructClassMethod = $node->getMethod(MethodName::CONSTRUCT);
-        if (! $constructClassMethod instanceof ClassMethod) {
+        if ($this->shouldSkipClass($node)) {
             return null;
         }
 
-        if ($this->classAnalyzer->isAnonymousClass($node)) {
+        $constructClassMethod = $node->getMethod(MethodName::CONSTRUCT);
+        if (! $constructClassMethod instanceof ClassMethod) {
             return null;
         }
 
@@ -218,4 +218,16 @@ private function isParentCallNamed(Node $node, string $desiredMethodName): bool
 
         return $this->nodeNameResolver->isName($node->name, $desiredMethodName);
     }
+
+    private function shouldSkipClass(Class_ $class): bool
+    {
+        $className = $this->getName($class);
+
+        // probably helper class with access to protected methods like createMock()
+        if (! str_ends_with((string) $className, 'Test') && ! str_ends_with((string) $className, 'TestCase')) {
+            return true;
+        }
+
+        return $this->classAnalyzer->isAnonymousClass($class);
+    }
 }