make RectorNodeTraverser immutable

Author: TomasVotruba

src/PhpParser/NodeTraverser/RectorNodeTraverser.php

@@ -16,6 +16,7 @@
 use Rector\PhpParser\Node\CustomNode\FileWithoutNamespace;
 use Rector\PhpParser\Node\FileNode;
 use Rector\VersionBonding\PhpVersionedFilter;
+use Webmozart\Assert\Assert;
 
 /**
  * Based on native NodeTraverser class, but heavily customized for Rector needs.
@@ -54,9 +55,13 @@ public function __construct(
     /**
      * @param RectorInterface[] $rectors
      * @api used in tests to update the active rules
+     *
+     * @internal Used only in Rector core, not supported outside. Might change any time.
      */
     public function refreshPhpRectors(array $rectors): void
     {
+        Assert::allIsInstanceOf($rectors, RectorInterface::class);
+
         $this->rectors = $rectors;
         $this->visitors = [];
         $this->visitorsPerNodeClass = [];
@@ -72,11 +77,14 @@ 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) {
@@ -95,12 +103,9 @@ 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

@@ -48,7 +48,7 @@ public function testGetVisitorsForNodeWhenNoVisitorsAvailable(): void
     public function testGetVisitorsForNodeWhenNoVisitorsMatch(): void
     {
         $class = new Class_('test');
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingFunctionRector);
+        $this->rectorNodeTraverser->refreshPhpRectors([$this->ruleUsingFunctionRector]);
 
         $visitors = $this->rectorNodeTraverser->getVisitorsForNode($class);
 
@@ -58,8 +58,11 @@ public function testGetVisitorsForNodeWhenNoVisitorsMatch(): void
     public function testGetVisitorsForNodeWhenSomeVisitorsMatch(): void
     {
         $class = new Class_('test');
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingFunctionRector);
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingClassRector);
+
+        $this->rectorNodeTraverser->refreshPhpRectors([
+            $this->ruleUsingFunctionRector,
+            $this->ruleUsingClassRector,
+        ]);
 
         $visitors = $this->rectorNodeTraverser->getVisitorsForNode($class);
 
@@ -69,8 +72,10 @@ public function testGetVisitorsForNodeWhenSomeVisitorsMatch(): void
     public function testGetVisitorsForNodeWhenAllVisitorsMatch(): void
     {
         $class = new Class_('test');
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingClassRector);
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingClassLikeRector);
+        $this->rectorNodeTraverser->refreshPhpRectors([
+            $this->ruleUsingClassRector,
+            $this->ruleUsingClassLikeRector,
+        ]);
 
         $visitors = $this->rectorNodeTraverser->getVisitorsForNode($class);