feat: add ClassExtendUsesAbstractClassWhenExisting rule with tests

Author: shyim

rules.neon

@@ -1,4 +1,5 @@
 rules:
+    - Shopware\PhpStan\Rule\ClassExtendUsesAbstractClassWhenExisting
     - Shopware\PhpStan\Rule\DisallowDefaultContextCreation
     - Shopware\PhpStan\Rule\ForbidGlobBraceRule
     - Shopware\PhpStan\Rule\DisallowFunctionsRule

src/Rule/ClassExtendUsesAbstractClassWhenExisting.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace Shopware\PhpStan\Rule;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\Class_;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\ReflectionProvider;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * @implements Rule<Class_>
+ */
+class ClassExtendUsesAbstractClassWhenExisting implements Rule
+{
+    private ReflectionProvider $reflectionProvider;
+
+    public function __construct(ReflectionProvider $reflectionProvider)
+    {
+        $this->reflectionProvider = $reflectionProvider;
+    }
+
+    /**
+     * This rule is applied to class nodes.
+     */
+    public function getNodeType(): string
+    {
+        return Class_::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        // Only proceed if the class extends a parent.
+        if ($node->extends === null) {
+            return [];
+        }
+
+        $parentClassName = (string) $node->extends;
+        $parentClassReflection = $this->reflectionProvider->getClass($parentClassName);
+
+        if (!$parentClassReflection->hasMethod('getDecorated')) {
+            return [];
+        }
+
+        foreach ($parentClassReflection->getParents() as $parent) {
+            if ($parent->isAbstract()) {
+                return [
+                    RuleErrorBuilder::message(sprintf('Class %s should extend %s to not break typehints', (string) $node->name, $parent->getName()))
+                        ->line($node->getLine())
+                        ->identifier('shopware.class.extends.abstract')
+                        ->build(),
+                ];
+            }
+        }
+
+        return [];
+    }
+}

tests/Rule/ClassExtendUsesAbstractClassWhenExistingTest.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Shopware\PhpStan\Tests\Rule;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use Shopware\PhpStan\Rule\ClassExtendUsesAbstractClassWhenExisting;
+
+class ClassExtendUsesAbstractClassWhenExistingTest extends RuleTestCase
+{
+    public function testAnalyse(): void
+    {
+        $this->analyse([__DIR__ . '/../data/ClassExtendUsesAbstractClassWhenExisting/extends.php'], [
+            [
+                <<<EOF
+Class Plugin should extend AbstractCore to not break typehints
+EOF,
+                16,
+            ],
+        ]);
+    }
+
+    protected function getRule(): Rule
+    {
+        return new ClassExtendUsesAbstractClassWhenExisting(self::createReflectionProvider());
+    }
+}

tests/data/ClassExtendUsesAbstractClassWhenExisting/extends.php

@@ -0,0 +1,22 @@
+<?php
+
+abstract class AbstractCore
+{
+    abstract public function getDecorated(): AbstractCore;
+}
+
+class Core extends AbstractCore
+{
+    public function getDecorated(): Core
+    {
+        return new Core();
+    }
+}
+
+class Plugin extends Core
+{
+    public function getDecorated(): Plugin
+    {
+        return new Plugin();
+    }
+}