[CodingStyle] Add RemoveUnusedAliasRector

config/level/coding-style/coding-style.yml

@@ -6,3 +6,4 @@ services:
     Rector\CodingStyle\Rector\Switch_\BinarySwitchToIfElseRector: ~
     Rector\CodingStyle\Rector\FuncCall\ConsistentImplodeRector: ~
     Rector\CodingStyle\Rector\FuncCall\SetTypeToCastRector: ~
+    Rector\CodingStyle\Rector\Use_\RemoveUnusedAliasRector: ~

packages/CodingStyle/src/Rector/Use_/RemoveUnusedAliasRector.php

@@ -0,0 +1,159 @@
+<?php declare(strict_types=1);
+
+namespace Rector\CodingStyle\Rector\Use_;
+
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\Node\Param;
+use PhpParser\Node\Stmt\Namespace_;
+use PhpParser\Node\Stmt\Use_;
+use PhpParser\NodeVisitor\NameResolver;
+use Rector\NodeTypeResolver\Node\Attribute;
+use Rector\PhpParser\Node\BetterNodeFinder;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+final class RemoveUnusedAliasRector extends AbstractRector
+{
+    /**
+     * @var BetterNodeFinder
+     */
+    private $betterNodeFinder;
+
+    public function __construct(BetterNodeFinder $betterNodeFinder)
+    {
+        $this->betterNodeFinder = $betterNodeFinder;
+    }
+
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Removes unused use aliases', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+use Symfony\Kernel as BaseKernel;
+
+class SomeClass extends BaseKernel
+{
+}
+CODE_SAMPLE
+                ,
+                <<<'CODE_SAMPLE'
+use Symfony\Kernel;
+
+class SomeClass extends Kernel
+{
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Use_::class];
+    }
+
+    /**
+     * @param Use_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        $parentNode = $node->getAttribute(Attribute::PARENT_NODE);
+        $usedNameNodes = $this->resolveUsedNameNodes($parentNode);
+        if ($usedNameNodes === []) {
+            return null;
+        }
+
+        foreach ($node->uses as $use) {
+            if ($use->alias === null) {
+                continue;
+            }
+
+            $lastName = $use->name->getLast();
+            $aliasName = $this->getName($use->alias);
+
+            // both are used → nothing to remove
+            if (isset($usedNameNodes[$lastName]) && isset($usedNameNodes[$aliasName])) {
+                continue;
+            }
+
+            // only last name is used → no need for alias
+            if (isset($usedNameNodes[$lastName])) {
+                $use->alias = null;
+                continue;
+            }
+
+            // only alis name is used → use last name directly
+            if (isset($usedNameNodes[$aliasName])) {
+                $this->renameNameNode($usedNameNodes, $aliasName, $lastName);
+                $use->alias = null;
+            }
+        }
+
+        return $node;
+    }
+
+    /**
+     * @return Name[][]|Node[][]
+     */
+    private function resolveUsedNameNodes(Node $parentNode): array
+    {
+        $usedNameNodes = [];
+
+        // assumption for namespaced content
+        if ($parentNode instanceof Namespace_) {
+            /** @var Name[] $namedNodes */
+            $namedNodes = $this->betterNodeFinder->find($parentNode, function (Node $node) {
+                if ($node instanceof Name) {
+                    return true;
+                }
+
+                return false;
+            });
+
+            foreach ($namedNodes as $nameNode) {
+                /** node name before becoming FQN - attribute from @see NameResolver */
+                $originalName = $nameNode->getAttribute('originalName');
+                if (! $originalName instanceof Name) {
+                    continue;
+                }
+
+                $usedNameNodes[$originalName->toString()][] = [
+                    $nameNode,
+                    $nameNode->getAttribute(Attribute::PARENT_NODE),
+                ];
+            }
+        }
+
+        return $usedNameNodes;
+    }
+
+    /**
+     * @param Name[][]|Node[][] $usedNameNodes
+     */
+    private function renameNameNode(array $usedNameNodes, string $aliasName, string $lastName): void
+    {
+        foreach ($usedNameNodes[$aliasName] as [$usedName, $parentNode]) {
+            foreach ($this->getObjectPublicPropertyNames($parentNode) as $parentNodePropertyName) {
+                if ($parentNode->{$parentNodePropertyName} !== $usedName) {
+                    continue;
+                }
+
+                $parentNode->{$parentNodePropertyName} = new Name($lastName);
+            }
+        }
+    }
+
+    /**
+     * @param object $node
+     * @return string[]
+     */
+    private function getObjectPublicPropertyNames($node): array
+    {
+        return array_keys(get_object_vars($node));
+    }
+}

packages/CodingStyle/tests/Rector/Use_/RemoveUnusedAliasRector/Fixture/fixture.php.inc

@@ -0,0 +1,31 @@
+<?php
+
+namespace Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel as BaseKernel;
+
+class SomeClass extends BaseKernel
+{
+    public function run(BaseKernel $baseKernel)
+    {
+        $anotherBaseKernel = new BaseKernel();
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel;
+
+class SomeClass extends AbstractKernel
+{
+    public function run(AbstractKernel $baseKernel)
+    {
+        $anotherBaseKernel = new AbstractKernel();
+    }
+}
+
+?>

packages/CodingStyle/tests/Rector/Use_/RemoveUnusedAliasRector/Fixture/used.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Fixture;
+
+use Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Source\AbstractKernel as BaseKernel;
+use Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Source\Another\AbstractKernel;
+
+class Used extends BaseKernel
+{
+    public function run(BaseKernel $baseKernel, AbstractKernel $abstractKernel)
+    {
+        $anotherBaseKernel = new BaseKernel();
+        $anotherAbstractKernel = new AbstractKernel();
+    }
+}

packages/CodingStyle/tests/Rector/Use_/RemoveUnusedAliasRector/RemoveUnusedAliasRectorTest.php

@@ -0,0 +1,22 @@
+<?php declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector;
+
+use Rector\CodingStyle\Rector\Use_\RemoveUnusedAliasRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class RemoveUnusedAliasRectorTest extends AbstractRectorTestCase
+{
+    public function test(): void
+    {
+        $this->doTestFiles([
+            __DIR__ . '/Fixture/fixture.php.inc',
+            __DIR__ . '/Fixture/used.php.inc',
+        ]);
+    }
+
+    protected function getRectorClass(): string
+    {
+        return RemoveUnusedAliasRector::class;
+    }
+}

packages/CodingStyle/tests/Rector/Use_/RemoveUnusedAliasRector/Source/AbstractKernel.php

@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Source;
+
+class AbstractKernel
+{
+
+}

packages/CodingStyle/tests/Rector/Use_/RemoveUnusedAliasRector/Source/Another/AbstractKernel.php

@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\Use_\RemoveUnusedAliasRector\Source\Another;
+
+class AbstractKernel
+{
+
+}

packages/NodeTypeResolver/src/NodeScopeAndMetadataDecorator.php

@@ -83,14 +83,17 @@ final class NodeScopeAndMetadataDecorator
     public function decorateNodesFromFile(array $nodes, string $filePath): array
     {
         $nodeTraverser = new NodeTraverser();
-        // specially rewrite nodes for PHPStan
-        $nodeTraverser->addVisitor(new NameResolver());
+        $nodeTraverser->addVisitor(new NameResolver(null, [
+            'preserveOriginalNames' => true,
+            'replaceNodes' => true, // required by PHPStan
+        ]));
         $nodes = $nodeTraverser->traverse($nodes);
 
         $nodes = $this->nodeScopeResolver->processNodes($nodes, $filePath);
 
         $nodeTraverser = new NodeTraverser();
         $nodeTraverser->addVisitor(new NameResolver(null, [
+            'preserveOriginalNames' => true,
             // this option would override old non-fqn-namespaced nodes otherwise, so it needs to be disabled
             'replaceNodes' => false,
         ]));