[DoctrineCodeQuality] Initialize collectoins in constructor

composer.json

@@ -55,6 +55,7 @@
             "Rector\\ConsoleDiffer\\": "packages/ConsoleDiffer/src",
             "Rector\\DeadCode\\": "packages/DeadCode/src",
             "Rector\\Doctrine\\": "packages/Doctrine/src",
+            "Rector\\DoctrineCodeQuality\\": "packages/DoctrineCodeQuality/src",
             "Rector\\ElasticSearchDSL\\": "packages/ElasticSearchDSL/src",
             "Rector\\FileSystemRector\\": "packages/FileSystemRector/src",
             "Rector\\Guzzle\\": "packages/Guzzle/src",
@@ -111,6 +112,7 @@
             "Rector\\CodingStyle\\Tests\\": "packages/CodingStyle/tests",
             "Rector\\DeadCode\\Tests\\": "packages/DeadCode/tests",
             "Rector\\Doctrine\\Tests\\": "packages/Doctrine/tests",
+            "Rector\\DoctrineCodeQuality\\Tests\\": "packages/DoctrineCodeQuality/tests",
             "Rector\\ElasticSearchDSL\\Tests\\": "packages/ElasticSearchDSL/tests",
             "Rector\\Guzzle\\Tests\\": "packages/Guzzle/tests",
             "Rector\\Laravel\\Tests\\": "packages/Laravel/tests",

config/set/doctrine/doctrine-code-quality.yaml

@@ -1,2 +1,3 @@
 services:
     Rector\Doctrine\Rector\Class_\ManagerRegistryGetManagerToEntityManagerRector: ~
+    Rector\DoctrineCodeQuality\Rector\Class_\InitializeDefaultEntityCollectionRector: ~

docs/AllRectorsOverview.md

@@ -3808,7 +3808,7 @@ Remove 0 from break and continue
 
 - class: `Rector\Php55\Rector\FuncCall\PregReplaceEModifierRector`
 
-The /e modifier is no longer supported, use preg_replace_callback instead 
+The /e modifier is no longer supported, use preg_replace_callback instead
 
 ```diff
  class SomeClass

docs/NodesOverview.md

@@ -917,7 +917,7 @@ if (true) {
 
 ```php
 ?>
-<strong>feel</strong><?php 
+<strong>feel</strong><?php
 ```
 <br>
 

packages/DoctrineCodeQuality/src/Rector/Class_/InitializeDefaultEntityCollectionRector.php

@@ -0,0 +1,190 @@
+<?php declare(strict_types=1);
+
+namespace Rector\DoctrineCodeQuality\Rector\Class_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\New_;
+use PhpParser\Node\Name\FullyQualified;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\Expression;
+use Rector\BetterPhpDocParser\Contract\Doctrine\ToManyTagNodeInterface;
+use Rector\BetterPhpDocParser\PhpDocNode\Doctrine\Class_\EntityTagValueNode;
+use Rector\Doctrine\ValueObject\DoctrineClass;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/best-practices.html#initialize-collections-in-the-constructor
+ *
+ * @see \Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector\InitializeDefaultEntityCollectionRectorTest
+ */
+final class InitializeDefaultEntityCollectionRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Initialize collection property in Entity constructor', [
+            new CodeSample(
+                <<<'PHP'
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity
+ */
+class SomeClass
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+}
+PHP
+                ,
+                <<<'PHP'
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity
+ */
+class SomeClass
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+
+    public function __construct()
+    {
+        $this->marketingEvents = new ArrayCollection();
+    }
+}
+PHP
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Class_::class];
+    }
+
+    /**
+     * @param Class_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        $classPhpDocInfo = $this->getPhpDocInfo($node);
+        if ($classPhpDocInfo === null) {
+            return null;
+        }
+
+        if (! $classPhpDocInfo->getByType(EntityTagValueNode::class)) {
+            return null;
+        }
+
+        $toManyPropertyNames = $this->resolveToManyPropertyNames($node);
+        if ($toManyPropertyNames === []) {
+            return null;
+        }
+
+        $constructClassMethod = $node->getMethod('__construct');
+        $assigns = $this->createAssignsOfArrayCollectionsForPropertyNames($toManyPropertyNames);
+
+        if ($constructClassMethod === null) {
+            $constructClassMethod = $this->nodeFactory->createPublicMethod('__construct');
+            $constructClassMethod->stmts = $assigns;
+
+            $node->stmts = array_merge((array) $node->stmts, [$constructClassMethod]);
+        } else {
+            $assigns = $this->filterOutExistingAssigns($constructClassMethod, $assigns);
+
+            // all properties are initialized → skip
+            if ($assigns === []) {
+                return null;
+            }
+
+            $constructClassMethod->stmts = array_merge($assigns, (array) $constructClassMethod->stmts);
+        }
+
+        return $node;
+    }
+
+    /**
+     * @return string[]
+     */
+    private function resolveToManyPropertyNames(Class_ $class): array
+    {
+        $collectionPropertyNames = [];
+
+        foreach ($class->getProperties() as $property) {
+            if (count($property->props) !== 1) {
+                continue;
+            }
+
+            $propertyPhpDocInfo = $this->getPhpDocInfo($property);
+            if ($propertyPhpDocInfo === null) {
+                continue;
+            }
+
+            if (! $propertyPhpDocInfo->getByType(ToManyTagNodeInterface::class)) {
+                continue;
+            }
+
+            /** @var string $propertyName */
+            $propertyName = $this->getName($property);
+
+            $collectionPropertyNames[] = $propertyName;
+        }
+
+        return $collectionPropertyNames;
+    }
+
+    /**
+     * @param string[] $propertyNames
+     * @return Expression[]
+     */
+    private function createAssignsOfArrayCollectionsForPropertyNames(array $propertyNames): array
+    {
+        $assigns = [];
+        foreach ($propertyNames as $propertyName) {
+            $assigns[] = $this->createPropertyArrayCollectionAssign($propertyName);
+        }
+
+        return $assigns;
+    }
+
+    private function createPropertyArrayCollectionAssign(string $toManyPropertyName): Expression
+    {
+        $propertyFetch = $this->createPropertyFetch('this', $toManyPropertyName);
+        $newCollection = new New_(new FullyQualified(DoctrineClass::ARRAY_COLLECTION));
+
+        $assign = new Assign($propertyFetch, $newCollection);
+
+        return new Expression($assign);
+    }
+
+    /**
+     * @param Expression[] $assigns
+     * @return Expression[]
+     */
+    private function filterOutExistingAssigns(Node\Stmt\ClassMethod $constructClassMethod, array $assigns): array
+    {
+        $this->traverseNodesWithCallable((array) $constructClassMethod->stmts, function (Node $node) use (&$assigns) {
+            foreach ($assigns as $key => $assign) {
+                if (! $this->areNodesEqual($node, $assign)) {
+                    continue;
+                }
+
+                unset($assigns[$key]);
+            }
+
+            return null;
+        });
+
+        return $assigns;
+    }
+}

packages/DoctrineCodeQuality/tests/Rector/Class_/InitializeDefaultEntityCollectionRector/Fixture/existing_constructor.php.inc

@@ -0,0 +1,48 @@
+<?php
+
+namespace Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector\Fixture;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity
+ */
+class ExistingConstructor
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+
+    public function __construct()
+    {
+        $value = 5;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector\Fixture;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity
+ */
+class ExistingConstructor
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+
+    public function __construct()
+    {
+        $this->marketingEvents = new \Doctrine\Common\Collections\ArrayCollection();
+        $value = 5;
+    }
+}
+
+?>

packages/DoctrineCodeQuality/tests/Rector/Class_/InitializeDefaultEntityCollectionRector/Fixture/fixture.php.inc

@@ -0,0 +1,41 @@
+<?php
+
+namespace Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector\Fixture;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity
+ */
+class SomeClass
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector\Fixture;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity
+ */
+class SomeClass
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+    public function __construct()
+    {
+        $this->marketingEvents = new \Doctrine\Common\Collections\ArrayCollection();
+    }
+}
+
+?>

packages/DoctrineCodeQuality/tests/Rector/Class_/InitializeDefaultEntityCollectionRector/Fixture/skip_added.php.inc

@@ -0,0 +1,23 @@
+<?php
+
+namespace Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector\Fixture;
+
+use Doctrine\ORM\Mapping as ORM;
+use Doctrine\Common\Collections\ArrayCollection;
+
+/**
+ * @ORM\Entity
+ */
+class SkipAdded
+{
+    /**
+     * @ORM\OneToMany(targetEntity="MarketingEvent")
+     */
+    private $marketingEvents = [];
+
+    public function __construct()
+    {
+        $this->marketingEvents = new ArrayCollection();
+        $value = 5;
+    }
+}

packages/DoctrineCodeQuality/tests/Rector/Class_/InitializeDefaultEntityCollectionRector/InitializeDefaultEntityCollectionRectorTest.php

@@ -0,0 +1,30 @@
+<?php declare(strict_types=1);
+
+namespace Rector\DoctrineCodeQuality\Tests\Rector\Class_\InitializeDefaultEntityCollectionRector;
+
+use Iterator;
+use Rector\DoctrineCodeQuality\Rector\Class_\InitializeDefaultEntityCollectionRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class InitializeDefaultEntityCollectionRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideDataForTest()
+     */
+    public function test(string $file): void
+    {
+        $this->doTestFile($file);
+    }
+
+    public function provideDataForTest(): Iterator
+    {
+        yield [__DIR__ . '/Fixture/fixture.php.inc'];
+        yield [__DIR__ . '/Fixture/existing_constructor.php.inc'];
+        yield [__DIR__ . '/Fixture/skip_added.php.inc'];
+    }
+
+    protected function getRectorClass(): string
+    {
+        return InitializeDefaultEntityCollectionRector::class;
+    }
+}