From 396f076b7115d876847d0811e41b2af712ee5d4d Mon Sep 17 00:00:00 2001
From: Tomas Votruba <tomas.vot@gmail.com>
Date: Wed, 7 Nov 2018 00:05:21 +0100
Subject: [PATCH] Fix too deep method chain calls performance on analysis

---
 .../Foreach_/ForeachToInArrayRector.php       |  2 +-
 .../src/PHPStan/Scope/NodeScopeResolver.php   | 24 ++++++-
 .../RemoveDeepChainMethodCallNodeVisitor.php  | 69 +++++++++++++++++++
 3 files changed, 93 insertions(+), 2 deletions(-)
 create mode 100644 packages/NodeTypeResolver/src/PHPStan/Scope/NodeVisitor/RemoveDeepChainMethodCallNodeVisitor.php

diff --git a/packages/CodeQuality/src/Rector/Foreach_/ForeachToInArrayRector.php b/packages/CodeQuality/src/Rector/Foreach_/ForeachToInArrayRector.php
index ea2efcaa32f..20efe5e0458 100644
--- a/packages/CodeQuality/src/Rector/Foreach_/ForeachToInArrayRector.php
+++ b/packages/CodeQuality/src/Rector/Foreach_/ForeachToInArrayRector.php
@@ -179,7 +179,7 @@ CODE_SAMPLE
 
         return $this->createFunction('in_array', $arguments);
     }
-    
+
     private function combineCommentsToNode(Node $originalNode, Node $newNode): void
     {
         $this->callableNodeTraverser->traverseNodesWithCallable([$originalNode], function (Node $node): void {
diff --git a/packages/NodeTypeResolver/src/PHPStan/Scope/NodeScopeResolver.php b/packages/NodeTypeResolver/src/PHPStan/Scope/NodeScopeResolver.php
index ac20d8a1bab..99d1f848618 100644
--- a/packages/NodeTypeResolver/src/PHPStan/Scope/NodeScopeResolver.php
+++ b/packages/NodeTypeResolver/src/PHPStan/Scope/NodeScopeResolver.php
@@ -5,10 +5,12 @@ namespace Rector\NodeTypeResolver\PHPStan\Scope;
 use PhpParser\Node;
 use PhpParser\Node\Stmt\Class_;
 use PhpParser\Node\Stmt\Interface_;
+use PhpParser\NodeTraverser;
 use PHPStan\Analyser\NodeScopeResolver as PHPStanNodeScopeResolver;
 use PHPStan\Analyser\Scope;
 use PHPStan\Broker\Broker;
 use Rector\NodeTypeResolver\Node\Attribute;
+use Rector\NodeTypeResolver\PHPStan\Scope\NodeVisitor\RemoveDeepChainMethodCallNodeVisitor;
 use Symplify\PackageBuilder\Reflection\PrivatesAccessor;
 
 /**
@@ -32,14 +34,21 @@ final class NodeScopeResolver
      */
     private $broker;
 
+    /**
+     * @var RemoveDeepChainMethodCallNodeVisitor
+     */
+    private $removeDeepChainMethodCallNodeVisitor;
+
     public function __construct(
         ScopeFactory $scopeFactory,
         PHPStanNodeScopeResolver $phpStanNodeScopeResolver,
-        Broker $broker
+        Broker $broker,
+        RemoveDeepChainMethodCallNodeVisitor $removeDeepChainMethodCallNodeVisitor
     ) {
         $this->scopeFactory = $scopeFactory;
         $this->phpStanNodeScopeResolver = $phpStanNodeScopeResolver;
         $this->broker = $broker;
+        $this->removeDeepChainMethodCallNodeVisitor = $removeDeepChainMethodCallNodeVisitor;
     }
 
     /**
@@ -48,8 +57,11 @@ final class NodeScopeResolver
      */
     public function processNodes(array $nodes, string $filePath): array
     {
+        $this->removeDeepChainMethodCallNodes($nodes);
+
         $this->phpStanNodeScopeResolver->setAnalysedFiles([$filePath]);
 
+        // skip chain method calls, performance issue: https://github.com/phpstan/phpstan/issues/254
         $this->phpStanNodeScopeResolver->processNodes(
             $nodes,
             $this->scopeFactory->createFromFile($filePath),
@@ -88,4 +100,14 @@ final class NodeScopeResolver
 
         return $scope;
     }
+
+    /**
+     * @param Node[] $nodes
+     */
+    private function removeDeepChainMethodCallNodes(array $nodes): void
+    {
+        $nodeTraverser = new NodeTraverser();
+        $nodeTraverser->addVisitor($this->removeDeepChainMethodCallNodeVisitor);
+        $nodeTraverser->traverse($nodes);
+    }
 }
diff --git a/packages/NodeTypeResolver/src/PHPStan/Scope/NodeVisitor/RemoveDeepChainMethodCallNodeVisitor.php b/packages/NodeTypeResolver/src/PHPStan/Scope/NodeVisitor/RemoveDeepChainMethodCallNodeVisitor.php
new file mode 100644
index 00000000000..bf78c5eff4b
--- /dev/null
+++ b/packages/NodeTypeResolver/src/PHPStan/Scope/NodeVisitor/RemoveDeepChainMethodCallNodeVisitor.php
@@ -0,0 +1,69 @@
+<?php declare(strict_types=1);
+
+namespace Rector\NodeTypeResolver\PHPStan\Scope\NodeVisitor;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\NodeTraverser;
+use PhpParser\NodeVisitorAbstract;
+use Rector\Utils\BetterNodeFinder;
+
+/**
+ * Skips performance trap in PHPStan: https://github.com/phpstan/phpstan/issues/254
+ */
+final class RemoveDeepChainMethodCallNodeVisitor extends NodeVisitorAbstract
+{
+    /**
+     * @var int
+     */
+    private const NESTED_CHAIN_METHOD_CALL_LIMIT = 10;
+
+    /**
+     * @var BetterNodeFinder
+     */
+    private $betterNodeFinder;
+
+    /**
+     * @var Expression|null
+     */
+    private $nodeToRemove;
+
+    public function __construct(BetterNodeFinder $betterNodeFinder)
+    {
+        $this->betterNodeFinder = $betterNodeFinder;
+    }
+
+    /**
+     * @return int|Node|null
+     */
+    public function enterNode(Node $node)
+    {
+        if (! $node instanceof Expression) {
+            return null;
+        }
+
+        if ($node->expr instanceof MethodCall && $node->expr->var instanceof MethodCall) {
+            $nestedChainMethodCalls = $this->betterNodeFinder->findInstanceOf([$node->expr], MethodCall::class);
+            if (count($nestedChainMethodCalls) > self::NESTED_CHAIN_METHOD_CALL_LIMIT) {
+                $this->nodeToRemove = $node;
+
+                return NodeTraverser::DONT_TRAVERSE_CHILDREN;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @return int|Node|Node[]|null
+     */
+    public function leaveNode(Node $node)
+    {
+        if ($node === $this->nodeToRemove) {
+            return NodeTraverser::REMOVE_NODE;
+        }
+
+        return $node;
+    }
+}