chore: Add unit test for ProviderPass.

tests/Unit/DependencyInjection/Compiler/ProviderPassTest.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace GeekCell\ImagekitBundle\Tests\Unit\DependencyInjection\Compiler;
+
+use GeekCell\ImagekitBundle\Contracts\Provider;
+use GeekCell\ImagekitBundle\DependencyInjection\Compiler\ProviderPass;
+use GeekCell\ImagekitBundle\Imagekit\ProviderRegistry;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Definition;
+
+class ProviderPassTest extends TestCase
+{
+    public function testProcess(): void
+    {
+        // Given
+        $container = new ContainerBuilder();
+
+        $providerRegistryDefinition = new Definition(ProviderRegistry::class);
+        $container->setDefinition(ProviderRegistry::class, $providerRegistryDefinition);
+
+        $firstProvider = new Definition(Provider::class);
+        $firstProvider->addTag('geek_cell_imagekit.provider');
+        $container->setDefinition('ignored.ignored.first', $firstProvider);
+
+        $secondProvider = new Definition(Provider::class);
+        $secondProvider->addTag('geek_cell_imagekit.provider');
+        $container->setDefinition('ignored.ignored.second', $secondProvider);
+
+        $invalidProvider = new Definition(\stdClass::class);
+        $invalidProvider->addTag('geek_cell_imagekit.provider');
+        $container->setDefinition('does.not.matter', $invalidProvider);
+
+        // When
+        (new ProviderPass())->process($container);
+
+        // Then
+        $calls = $providerRegistryDefinition->getMethodCalls();
+        $this->assertCount(2, $calls);
+
+        $this->assertEquals('register', $calls[0][0]);
+        $this->assertEquals('first', $calls[0][1][0]);
+
+        $this->assertEquals('register', $calls[1][0]);
+        $this->assertEquals('second', $calls[1][1][0]);
+    }
+}