Fix conditional services referencing not-yet registered services

tests/php/src/Fixture/DummyService.php

@@ -6,4 +6,13 @@
 
 final class DummyService implements Service {
 
+	/**
+	 * A method that can be triggered for tests.
+	 *
+	 * @return bool Always returns true.
+	 */
+	public function method_to_trigger()
+	{
+		return true;
+	}
 }

tests/php/src/Fixture/DummyServiceWithCondition.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace AmpProject\AmpWP\Tests\Fixture;
+
+use AmpProject\AmpWP\Infrastructure\Conditional;
+use AmpProject\AmpWP\Infrastructure\Service;
+
+class DummyServiceWithCondition implements Service, Conditional {
+
+	/**
+	 * Check whether the conditional object is currently needed.
+	 *
+	 * @return bool Whether the conditional object is needed.
+	 */
+	public static function is_needed()
+	{
+		return true;
+	}
+}

tests/php/src/Fixture/DummyServiceWithReferencingCondition.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace AmpProject\AmpWP\Tests\Fixture;
+
+use AmpProject\AmpWP\Infrastructure\Conditional;
+use AmpProject\AmpWP\Infrastructure\Service;
+use AmpProject\AmpWP\Services;
+
+class DummyServiceWithReferencingCondition implements Service, Conditional {
+
+	/**
+	 * Check whether the conditional object is currently needed.
+	 *
+	 * @return bool Whether the conditional object is needed.
+	 */
+	public static function is_needed()
+	{
+		/** @var DummyService $service */
+		$service = Services::get( 'service_a' );
+
+		return $service->method_to_trigger();
+	}
+}

tests/php/src/Infrastructure/ServiceBasedPluginTest.php

@@ -8,7 +8,9 @@
 use AmpProject\AmpWP\Infrastructure\ServiceContainer\SimpleServiceContainer;
 use AmpProject\AmpWP\Tests\Fixture\DummyService;
 use AmpProject\AmpWP\Tests\Fixture\DummyServiceBasedPlugin;
+use AmpProject\AmpWP\Tests\Fixture\DummyServiceWithCondition;
 use AmpProject\AmpWP\Tests\Fixture\DummyServiceWithDelay;
+use AmpProject\AmpWP\Tests\Fixture\DummyServiceWithReferencingCondition;
 use AmpProject\AmpWP\Tests\Fixture\DummyServiceWithRequirements;
 use AmpProject\AmpWP\Tests\TestCase;
 
@@ -63,7 +65,6 @@ public function test_it_registers_default_services() {
 		$plugin    = $this->getMockBuilder( DummyServiceBasedPlugin::class )
 			->enableOriginalConstructor()
 			->setConstructorArgs( [ true, null, $container ] )
-			->setMethods()
 			->setMethodsExcept(
 				[
 					'register',
@@ -238,6 +239,87 @@ public function test_it_handles_delays_for_requirements() {
 		$this->assertInstanceof( DummyServiceWithRequirements::class, $container->get( 'service_with_requirements' ) );
 	}
 
+	public function test_it_handles_conditions_for_requirements() {
+		$container = new SimpleServiceContainer();
+		$plugin    = $this->getMockBuilder( DummyServiceBasedPlugin::class )
+		                  ->enableOriginalConstructor()
+		                  ->setConstructorArgs( [ true, null, $container ] )
+		                  ->setMethodsExcept(
+			                  [
+				                  'collect_missing_requirements',
+				                  'register',
+				                  'register_services',
+				                  'requirements_are_met',
+				                  'get_container',
+				                  'get_service_classes',
+			                  ]
+		                  )
+		                  ->getMock();
+
+		$service_callback = static function ( $services ) {
+			return array_merge(
+				$services,
+				[
+					'service_with_requirements' => DummyServiceWithRequirements::class,
+					'service_a'                 => DummyServiceWithCondition::class,
+				]
+			);
+		};
+
+		add_filter( 'services', $service_callback );
+
+		$plugin->register();
+
+		$this->assertEquals( 4, count( $container ) );
+		$this->assertTrue( $container->has( 'service_a' ) );
+		$this->assertInstanceof( DummyServiceWithCondition::class, $container->get( 'service_a' ) );
+		$this->assertTrue( $container->has( 'service_b' ) );
+		$this->assertInstanceof( DummyService::class, $container->get( 'service_b' ) );
+		$this->assertTrue( $container->has( 'service_with_requirements' ) );
+		$this->assertInstanceof( DummyServiceWithRequirements::class, $container->get( 'service_with_requirements' ) );
+	}
+
+	public function test_it_handles_referencing_conditions_for_requirements() {
+		$container = new SimpleServiceContainer();
+		$plugin    = $this->getMockBuilder( DummyServiceBasedPlugin::class )
+		                  ->enableOriginalConstructor()
+		                  ->setConstructorArgs( [ true, null, $container ] )
+		                  ->setMethodsExcept(
+			                  [
+				                  'collect_missing_requirements',
+				                  'register',
+				                  'register_services',
+				                  'requirements_are_met',
+				                  'get_container',
+				                  'get_service_classes',
+			                  ]
+		                  )
+		                  ->getMock();
+
+		$service_callback = static function ( $services ) {
+			return array_merge(
+				$services,
+				[
+					'service_with_requirements' => DummyServiceWithRequirements::class,
+					'service_b'                 => DummyServiceWithReferencingCondition::class,
+					'service_a'                 => DummyService::class,
+				]
+			);
+		};
+
+		add_filter( 'services', $service_callback );
+
+		$plugin->register();
+
+		$this->assertEquals( 4, count( $container ) );
+		$this->assertTrue( $container->has( 'service_a' ) );
+		$this->assertInstanceof( DummyServiceWithReferencingCondition::class, $container->get( 'service_b' ) );
+		$this->assertTrue( $container->has( 'service_b' ) );
+		$this->assertInstanceof( DummyService::class, $container->get( 'service_a' ) );
+		$this->assertTrue( $container->has( 'service_with_requirements' ) );
+		$this->assertInstanceof( DummyServiceWithRequirements::class, $container->get( 'service_with_requirements' ) );
+	}
+
 	public function test_it_throws_an_exception_if_unrecognized_service_is_required() {
 		$container = new SimpleServiceContainer();
 		$plugin    = $this->getMockBuilder( DummyServiceBasedPlugin::class )