[typed-collections] Add RemoveUselessIsEmptyAssignRector (#437)

Author: TomasVotruba

config/sets/typed-collections.php

@@ -29,6 +29,7 @@
 use Rector\Doctrine\TypedCollections\Rector\If_\RemoveIfCollectionIdenticalToNullRector;
 use Rector\Doctrine\TypedCollections\Rector\If_\RemoveIfInstanceofCollectionRector;
 use Rector\Doctrine\TypedCollections\Rector\If_\RemoveIsArrayOnCollectionRector;
+use Rector\Doctrine\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector;
 use Rector\Doctrine\TypedCollections\Rector\MethodCall\AssertNullOnCollectionToAssertEmptyRector;
 use Rector\Doctrine\TypedCollections\Rector\MethodCall\AssertSameCountOnCollectionToAssertCountRector;
 use Rector\Doctrine\TypedCollections\Rector\MethodCall\SetArrayToNewCollectionRector;
@@ -87,6 +88,7 @@
 
         // cleanup
         RemoveNullsafeOnCollectionRector::class,
+        RemoveUselessIsEmptyAssignRector::class,
 
         // test assertions
         RemoveAssertNotNullOnCollectionRector::class,

rules-tests/TypedCollections/Rector/If_/RemoveUselessIsEmptyAssignRector/Fixture/remove_useless.php.inc

@@ -0,0 +1,41 @@
+<?php
+
+namespace Rector\Doctrine\Tests\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector\Fixture;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+
+final class RemoveUseless
+{
+    public Collection $items;
+
+    public function someMethod()
+    {
+        if ($this->items->isEmpty()) {
+            $this->items = new ArrayCollection();
+        }
+
+        return $this->items;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Doctrine\Tests\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector\Fixture;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+
+final class RemoveUseless
+{
+    public Collection $items;
+
+    public function someMethod()
+    {
+        return $this->items;
+    }
+}
+
+?>

rules-tests/TypedCollections/Rector/If_/RemoveUselessIsEmptyAssignRector/Fixture/skip_different_new.php.inc

@@ -0,0 +1,20 @@
+<?php
+
+namespace Rector\Doctrine\Tests\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector\Fixture;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+
+final class SkipDifferentNew
+{
+    public Collection $items;
+
+    public function someMethod()
+    {
+        if ($this->items->isEmpty()) {
+            $this->items = new \stdClass();
+        }
+
+        return $this->items;
+    }
+}

rules-tests/TypedCollections/Rector/If_/RemoveUselessIsEmptyAssignRector/Fixture/skip_different_variable.php.inc

@@ -0,0 +1,20 @@
+<?php
+
+namespace Rector\Doctrine\Tests\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector\Fixture;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+
+final class SkipDifferentVariable
+{
+    public Collection $items;
+
+    public function someMethod()
+    {
+        if ($this->items->isEmpty()) {
+            $this->another = new ArrayCollection();
+        }
+
+        return $this->items;
+    }
+}

rules-tests/TypedCollections/Rector/If_/RemoveUselessIsEmptyAssignRector/RemoveUselessIsEmptyAssignRectorTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Doctrine\Tests\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class RemoveUselessIsEmptyAssignRectorTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

rules-tests/TypedCollections/Rector/If_/RemoveUselessIsEmptyAssignRector/config/configured_rule.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Doctrine\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(RemoveUselessIsEmptyAssignRector::class);
+};

rules/TypedCollections/Rector/If_/RemoveUselessIsEmptyAssignRector.php

@@ -0,0 +1,132 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Doctrine\TypedCollections\Rector\If_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Expr\New_;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\If_;
+use PhpParser\NodeVisitor;
+use Rector\Doctrine\Enum\DoctrineClass;
+use Rector\Doctrine\TypedCollections\TypeAnalyzer\CollectionTypeDetector;
+use Rector\Rector\AbstractRector;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @see \Rector\Doctrine\Tests\TypedCollections\Rector\If_\RemoveUselessIsEmptyAssignRector\RemoveUselessIsEmptyAssignRectorTest
+ */
+final class RemoveUselessIsEmptyAssignRector extends AbstractRector
+{
+    public function __construct(
+        private readonly CollectionTypeDetector $collectionTypeDetector,
+    ) {
+
+    }
+
+    public function getNodeTypes(): array
+    {
+        return [If_::class];
+    }
+
+    /**
+     * @param If_ $node
+     */
+    public function refactor(Node $node): ?int
+    {
+        if (! $node->cond instanceof MethodCall) {
+            return null;
+        }
+
+        $methodCall = $node->cond;
+        if (! $this->isName($methodCall->name, 'isEmpty')) {
+            return null;
+        }
+
+        if (! $this->collectionTypeDetector->isCollectionType($methodCall->var)) {
+            return null;
+        }
+
+        if (count($node->stmts) !== 1) {
+            return null;
+        }
+
+        $soleStmts = $node->stmts[0];
+
+        if (! $soleStmts instanceof Expression) {
+            return null;
+        }
+
+        if (! $soleStmts->expr instanceof Assign) {
+            return null;
+        }
+
+        $assign = $soleStmts->expr;
+        if (! $this->nodeNameResolver->areNamesEqual($assign->var, $methodCall->var)) {
+            return null;
+        }
+
+        if (! $this->isArrayCollectionNewInstance($assign->expr)) {
+            return null;
+        }
+
+        return NodeVisitor::REMOVE_NODE;
+    }
+
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition(
+            'Remove useless isEmpty() check on collection with following new ArrayCollection() instance',
+            [
+                new CodeSample(
+                    <<<'CODE_SAMPLE'
+use Doctrine\Common\Collections\Collection;
+
+final class SomeClass
+{
+    private Collection $collection;
+
+    public function someMethod()
+    {
+        if ($this->collection->isEmpty()) {
+            $this->collection = new ArrayCollection();
+        }
+
+        return $this->collection;
+    }
+}
+CODE_SAMPLE
+                    ,
+                    <<<'CODE_SAMPLE'
+use Doctrine\Common\Collections\Collection;
+
+final class SomeClass
+{
+    private Collection $collection;
+
+    public function someMethod()
+    {
+        return $this->collection;
+    }
+}
+CODE_SAMPLE
+                ),
+
+            ]
+        );
+    }
+
+    private function isArrayCollectionNewInstance(Expr $expr): bool
+    {
+        if (! $expr instanceof New_) {
+            return true;
+        }
+
+        return $this->isName($expr->class, DoctrineClass::ARRAY_COLLECTION);
+    }
+}