make RectorNodeTraverser immutable

Author: TomasVotruba

phpstan.neon

@@ -385,15 +385,8 @@ parameters:
             path: src/PhpParser/NodeTraverser/RectorNodeTraverser.php
         -
             identifier: offsetAccess.nonArray
-<<<<<<< HEAD
-            path: src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php
-
-=======
             path: src/PhpParser/NodeTraverser/RectorNodeTraverser.php
-        -
-            message: '#Property PhpParser\\Node\\Stmt\\ClassMethod\:\:\$stmts \(array<PhpParser\\Node\\Stmt>\|null\) does not accept array<PhpParser\\Node>#'
-            path: scripts/create-immutable-node-visitor.php
->>>>>>> bb4e608ca7 ([int] merge AbstractImmutableNodeTraverser and RectorNodeTraverser as sole child and tight design)
+
         -
             message: '#Property Rector\\PhpParser\\NodeTraverser\\AbstractImmutableNodeTraverser\:\:\$visitors \(list<PhpParser\\NodeVisitor>\) does not accept array<int\|string, PhpParser\\NodeVisitor>#'
             path: src/PhpParser/NodeTraverser/RectorNodeTraverser.php

src/PhpParser/NodeTraverser/RectorNodeTraverser.php

@@ -79,11 +79,14 @@ public function getVisitorsForNode(Node $node): array
     {
         $nodeClass = $node::class;
 
+        if (! $this->areNodeVisitorsPrepared) {
+            $this->prepareNodeVisitors();
+        }
+
         if (! isset($this->visitorsPerNodeClass[$nodeClass])) {
             $this->visitorsPerNodeClass[$nodeClass] = [];
 
-            /** @var RectorInterface $visitor */
-            foreach ($this->visitors as $visitor) {
+            foreach ($this->rectors as $visitor) {
                 foreach ($visitor->getNodeTypes() as $nodeType) {
                     // BC layer matching
                     if ($nodeType === FileWithoutNamespace::class && $nodeClass === FileNode::class) {
@@ -102,12 +105,9 @@ public function getVisitorsForNode(Node $node): array
         return $this->visitorsPerNodeClass[$nodeClass];
     }
 
-    /**
-     * @deprecated @todo remove completely, even in tests to avoid mutable state
-     */
     public function addVisitor(NodeVisitor $visitor): void
     {
-        $this->visitors[] = $visitor;
+        throw new ShouldNotHappenException('The immutable node traverser does not support adding visitors.');
     }
 
     public function removeVisitor(NodeVisitor $visitor): void

tests/PhpParser/NodeTraverser/RectorNodeTraverserTest.php

@@ -58,6 +58,7 @@ public function testGetVisitorsForNodeWhenNoVisitorsMatch(): void
     public function testGetVisitorsForNodeWhenSomeVisitorsMatch(): void
     {
         $class = new Class_('test');
+
         $this->rectorNodeTraverser->refreshPhpRectors([
             $this->ruleUsingFunctionRector,
             $this->ruleUsingClassRector,