Add tests for Rule::namespace() shortcut method

Tests verify that the shortcut:
- Works correctly to filter classes by namespace
- Detects violations properly
- Supports multiple namespaces
- Produces equivalent results to the full syntax

Author: claude

tests/Integration/RuleNamespaceShortcutTest.php

@@ -0,0 +1,148 @@
+<?php
+declare(strict_types=1);
+
+namespace Arkitect\Tests\Integration;
+
+use Arkitect\Expression\ForClasses\HaveNameMatching;
+use Arkitect\Expression\ForClasses\ResideInOneOfTheseNamespaces;
+use Arkitect\Rules\Rule;
+use Arkitect\Tests\Utils\TestRunner;
+use org\bovigo\vfs\vfsStream;
+use PHPUnit\Framework\TestCase;
+
+class RuleNamespaceShortcutTest extends TestCase
+{
+    public function test_namespace_shortcut_works_same_as_full_syntax(): void
+    {
+        $dir = vfsStream::setup('root', null, $this->createDummyProject())->url();
+
+        $runner = TestRunner::create('8.4');
+
+        $rule = Rule::namespace('App\HappyIsland')
+            ->should(new HaveNameMatching('Happy*'))
+            ->because("that's what she said");
+
+        $runner->run($dir, $rule);
+
+        self::assertCount(0, $runner->getViolations());
+        self::assertCount(0, $runner->getParsingErrors());
+    }
+
+    public function test_namespace_shortcut_detects_violations(): void
+    {
+        $dir = vfsStream::setup('root', null, $this->createDummyProject())->url();
+
+        $runner = TestRunner::create('8.4');
+
+        $rule = Rule::namespace('App\HappyIsland')
+            ->should(new HaveNameMatching('Sad*'))
+            ->because('we want sad names');
+
+        $runner->run($dir, $rule);
+
+        self::assertCount(1, $runner->getViolations());
+    }
+
+    public function test_namespace_shortcut_supports_multiple_namespaces(): void
+    {
+        $dir = vfsStream::setup('root', null, $this->createDummyProject())->url();
+
+        $runner = TestRunner::create('8.4');
+
+        $rule = Rule::namespace('App\HappyIsland', 'App\BadCode')
+            ->should(new HaveNameMatching('*Code'))
+            ->because('we want Code suffix');
+
+        $runner->run($dir, $rule);
+
+        // HappyClass doesn't match *Code pattern, so we should have 1 violation
+        self::assertCount(1, $runner->getViolations());
+    }
+
+    public function test_namespace_shortcut_is_equivalent_to_full_syntax(): void
+    {
+        $dir = vfsStream::setup('root', null, $this->createDummyProject())->url();
+
+        $runner = TestRunner::create('8.4');
+
+        // Using shortcut
+        $shortcutRule = Rule::namespace('App\HappyIsland')
+            ->should(new HaveNameMatching('Happy*'))
+            ->because('test');
+
+        $runner->run($dir, $shortcutRule);
+        $shortcutViolations = $runner->getViolations();
+
+        // Using full syntax
+        $fullRule = Rule::allClasses()
+            ->that(new ResideInOneOfTheseNamespaces('App\HappyIsland'))
+            ->should(new HaveNameMatching('Happy*'))
+            ->because('test');
+
+        $runner->run($dir, $fullRule);
+        $fullViolations = $runner->getViolations();
+
+        self::assertCount(\count($shortcutViolations), $fullViolations);
+    }
+
+    public function createDummyProject(): array
+    {
+        return [
+            'BadCode' => [
+                'BadCode.php' => <<<'EOF'
+                    <?php
+
+                    namespace App\BadCode;
+
+                    class BadCode
+                    {
+                        private $happy;
+
+                        public function __construct(HappyClass $happy)
+                        {
+                            $this->happy = $happy;
+                        }
+                    }
+                    EOF,
+            ],
+            'OtherBadCode' => [
+                'OtherBadCode.php' => <<<'EOF'
+                    <?php
+
+                    namespace App\BadCode;
+
+                    class OtherBadCode
+                    {
+                        private $happy;
+
+                        public function __construct(HappyClass $happy)
+                        {
+                            $this->happy = $happy;
+                        }
+                    }
+                    EOF,
+            ],
+
+            'HappyIsland' => [
+                'HappyClass.php' => <<<'EOF'
+                    <?php
+
+                    namespace App\HappyIsland;
+
+                    class HappyClass
+                    {
+                        /**
+                         * @var BadCode
+                         */
+                        private $bad;
+
+                        public function __construct(BadCode $bad)
+                        {
+                            $this->bad = $bad;
+                        }
+                    }
+                    EOF,
+            ],
+        ];
+    }
+}