[DI] scope singly-implemented interfaces detection by file

src/Symfony/Component/DependencyInjection/Loader/Configurator/ContainerConfigurator.php

@@ -73,6 +73,8 @@ class ContainerConfigurator extends AbstractConfigurator
 
     final public function services(): ServicesConfigurator
     {
+        $this->loader->resetBeforeConfiguringServices();
+
         return new ServicesConfigurator($this->container, $this->loader, $this->instanceof, $this->path, $this->anonymousCount);
     }
 }

src/Symfony/Component/DependencyInjection/Loader/Configurator/ServicesConfigurator.php

@@ -105,6 +105,7 @@ class ServicesConfigurator extends AbstractConfigurator
         $ref = static::processValue($referencedId, true);
         $alias = new Alias((string) $ref, $this->defaults->isPublic());
         $this->container->setAlias($id, $alias);
+        $this->loader->removeSinglyImplementedAlias((string) $ref);
 
         return new AliasConfigurator($this, $alias);
     }

src/Symfony/Component/DependencyInjection/Loader/FileLoader.php

@@ -29,6 +29,9 @@ abstract class FileLoader extends BaseFileLoader
     protected $container;
     protected $isLoadingInstanceof = false;
     protected $instanceof = [];
+    protected $interfaces = [];
+    protected $singlyImplemented = [];
+    protected $singlyImplementedAliases = [];
 
     public function __construct(ContainerBuilder $container, FileLocatorInterface $locator)
     {
@@ -57,12 +60,10 @@ abstract class FileLoader extends BaseFileLoader
         $classes = $this->findClasses($namespace, $resource, (array) $exclude);
         // prepare for deep cloning
         $serializedPrototype = serialize($prototype);
-        $interfaces = [];
-        $singlyImplemented = [];
 
         foreach ($classes as $class => $errorMessage) {
             if (interface_exists($class, false)) {
-                $interfaces[] = $class;
+                $this->interfaces[] = $class;
             } else {
                 $this->setDefinition($class, $definition = unserialize($serializedPrototype));
                 if (null !== $errorMessage) {
@@ -71,14 +72,17 @@ abstract class FileLoader extends BaseFileLoader
                     continue;
                 }
                 foreach (class_implements($class, false) as $interface) {
-                    $singlyImplemented[$interface] = isset($singlyImplemented[$interface]) ? false : $class;
+                    $this->singlyImplemented[$interface] = isset($this->singlyImplemented[$interface]) ? false : $class;
                 }
             }
         }
-        foreach ($interfaces as $interface) {
-            if (!empty($singlyImplemented[$interface])) {
-                $this->container->setAlias($interface, $singlyImplemented[$interface])
-                    ->setPublic(false);
+
+        foreach ($this->interfaces as $interface) {
+            if (!empty($this->singlyImplemented[$interface]) && !$this->container->hasAlias($interface)) {
+                $this->container->setAlias($interface, $this->singlyImplemented[$interface])->setPublic(false);
+                $this->singlyImplementedAliases[$interface] = true;
+            } elseif ($this->singlyImplementedAliases[$interface] ?? false) {
+                $this->container->removeAlias($interface);
             }
         }
     }

src/Symfony/Component/DependencyInjection/Loader/PhpFileLoader.php

@@ -63,6 +63,18 @@ class PhpFileLoader extends FileLoader
 
         return 'php' === $type;
     }
+
+    public function resetBeforeConfiguringServices(): void
+    {
+        $this->interfaces = [];
+        $this->singlyImplemented = [];
+        $this->singlyImplementedAliases = [];
+    }
+
+    public function removeSinglyImplementedAlias(string $alias): void
+    {
+        unset($this->singlyImplementedAliases[$alias]);
+    }
 }
 
 /**

src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php

@@ -66,6 +66,9 @@ class XmlFileLoader extends FileLoader
             $this->parseDefinitions($xml, $path, $defaults);
         } finally {
             $this->instanceof = [];
+            $this->interfaces = [];
+            $this->singlyImplemented = [];
+            $this->singlyImplementedAliases = [];
         }
     }
 
@@ -194,6 +197,7 @@ class XmlFileLoader extends FileLoader
             $this->validateAlias($service, $file);
 
             $this->container->setAlias((string) $service->getAttribute('id'), $alias = new Alias($alias));
+            unset($this->singlyImplementedAliases[(string) $service->getAttribute('id')]);
             if ($publicAttr = $service->getAttribute('public')) {
                 $alias->setPublic(XmlUtils::phpize($publicAttr));
             } elseif (isset($defaults['public'])) {

src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php

@@ -150,6 +150,9 @@ class YamlFileLoader extends FileLoader
             $this->parseDefinitions($content, $path);
         } finally {
             $this->instanceof = [];
+            $this->interfaces = [];
+            $this->singlyImplemented = [];
+            $this->singlyImplementedAliases = [];
         }
     }
 
@@ -318,6 +321,7 @@ class YamlFileLoader extends FileLoader
 
         if (\is_string($service) && 0 === strpos($service, '@')) {
             $this->container->setAlias($id, $alias = new Alias(substr($service, 1)));
+            unset($this->singlyImplementedAliases[$id]);
             if (isset($defaults['public'])) {
                 $alias->setPublic($defaults['public']);
             }
@@ -341,6 +345,7 @@ class YamlFileLoader extends FileLoader
 
         if (isset($service['alias'])) {
             $this->container->setAlias($id, $alias = new Alias($service['alias']));
+            unset($this->singlyImplementedAliases[$id]);
             if (\array_key_exists('public', $service)) {
                 $alias->setPublic($service['public']);
             } elseif (isset($defaults['public'])) {

src/Symfony/Component/DependencyInjection/Tests/Fixtures/Prototype/SinglyImplementedInterface/Adapter/Adapter.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter;
+
+use Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\PortInterface;
+
+class Adapter implements PortInterface
+{
+}

src/Symfony/Component/DependencyInjection/Tests/Fixtures/Prototype/SinglyImplementedInterface/AnotherAdapter/Adapter.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter;
+
+use Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\PortInterface;
+
+class Adapter implements PortInterface
+{
+}

src/Symfony/Component/DependencyInjection/Tests/Fixtures/Prototype/SinglyImplementedInterface/Port/PortInterface.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port;
+
+interface PortInterface
+{
+}

src/Symfony/Component/DependencyInjection/Tests/Fixtures/config/prototype.php

@@ -9,7 +9,7 @@ return function (ContainerConfigurator $c) {
         ->tag('baz');
     $di->load(Prototype::class.'\\', '../Prototype')
         ->autoconfigure()
-        ->exclude('../Prototype/{OtherDir,BadClasses}')
+        ->exclude('../Prototype/{OtherDir,BadClasses,SinglyImplementedInterface}')
         ->factory('f')
         ->deprecate('%service_id%')
         ->args([0])

src/Symfony/Component/DependencyInjection/Tests/Fixtures/config/prototype_array.php

@@ -9,7 +9,7 @@ return function (ContainerConfigurator $c) {
         ->tag('baz');
     $di->load(Prototype::class.'\\', '../Prototype')
         ->autoconfigure()
-        ->exclude(['../Prototype/OtherDir', '../Prototype/BadClasses'])
+        ->exclude(['../Prototype/OtherDir', '../Prototype/BadClasses', '../Prototype/SinglyImplementedInterface'])
         ->factory('f')
         ->deprecate('%service_id%')
         ->args([0])

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/not_singly_implemented_interface_in_multiple_resources.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
+  <services>
+    <defaults autowire="true" />
+
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\"
+               resource="../Prototype/SinglyImplementedInterface/Adapter/*" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter\"
+               resource="../Prototype/SinglyImplementedInterface/AnotherAdapter/*" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\"
+               resource="../Prototype/SinglyImplementedInterface/Port/*" />
+  </services>
+</container>

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
+  <services>
+    <defaults autowire="true" />
+
+    <service id="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\PortInterface"
+             alias="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\Adapter" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\"
+               resource="../Prototype/SinglyImplementedInterface/Port/*" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\"
+               resource="../Prototype/SinglyImplementedInterface/Adapter/*" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter\"
+               resource="../Prototype/SinglyImplementedInterface/AnotherAdapter/*" />
+  </services>
+</container>

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias2.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
+  <services>
+    <defaults autowire="true" />
+
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\"
+               resource="../Prototype/SinglyImplementedInterface/Port/*" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\"
+               resource="../Prototype/SinglyImplementedInterface/Adapter/*" />
+    <service id="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\PortInterface"
+             alias="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\Adapter" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter\"
+               resource="../Prototype/SinglyImplementedInterface/AnotherAdapter/*" />
+  </services>
+</container>

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services_prototype.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <container xmlns="http://symfony.com/schema/dic/services" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
   <services>
-      <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\" resource="../Prototype/*" exclude="../Prototype/{OtherDir,BadClasses}" />
+      <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\" resource="../Prototype/*" exclude="../Prototype/{OtherDir,BadClasses,SinglyImplementedInterface}" />
   </services>
 </container>

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services_prototype_array.xml

@@ -4,6 +4,7 @@
       <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\" resource="../Prototype/*">
           <exclude>../Prototype/OtherDir</exclude>
           <exclude>../Prototype/BadClasses</exclude>
+          <exclude>../Prototype/SinglyImplementedInterface</exclude>
       </prototype>
   </services>
 </container>

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/singly_implemented_interface_in_multiple_resources.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
+  <services>
+    <defaults autowire="true" />
+
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\"
+               resource="../Prototype/SinglyImplementedInterface/Port/*" />
+    <prototype namespace="Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\"
+               resource="../Prototype/SinglyImplementedInterface/Adapter/*" />
+  </services>
+</container>

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/not_singly_implemented_interface_in_multiple_resources.yml

@@ -0,0 +1,12 @@
+services:
+    _defaults:
+        autowire: true
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\:
+        resource: ../Prototype/SinglyImplementedInterface/Adapter/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter\:
+        resource: ../Prototype/SinglyImplementedInterface/AnotherAdapter/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\:
+        resource: ../Prototype/SinglyImplementedInterface/Port/*

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias.yml

@@ -0,0 +1,15 @@
+services:
+    _defaults:
+        autowire: true
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\PortInterface:
+        alias: Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\Adapter
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\:
+        resource: ../Prototype/SinglyImplementedInterface/Port/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\:
+        resource: ../Prototype/SinglyImplementedInterface/Adapter/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter\:
+        resource: ../Prototype/SinglyImplementedInterface/AnotherAdapter/*

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias2.yml

@@ -0,0 +1,15 @@
+services:
+    _defaults:
+        autowire: true
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\:
+        resource: ../Prototype/SinglyImplementedInterface/Port/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\:
+        resource: ../Prototype/SinglyImplementedInterface/Adapter/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\PortInterface:
+        alias: Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\Adapter
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\AnotherAdapter\:
+        resource: ../Prototype/SinglyImplementedInterface/AnotherAdapter/*

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_prototype.yml

@@ -1,4 +1,4 @@
 services:
     Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\:
         resource: ../Prototype
-        exclude: '../Prototype/{OtherDir,BadClasses}'
+        exclude: '../Prototype/{OtherDir,BadClasses,SinglyImplementedInterface}'

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/singly_implemented_interface_in_multiple_resources.yml

@@ -0,0 +1,9 @@
+services:
+    _defaults:
+        autowire: true
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Port\:
+        resource: ../Prototype/SinglyImplementedInterface/Port/*
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\SinglyImplementedInterface\Adapter\:
+        resource: ../Prototype/SinglyImplementedInterface/Adapter/*

src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php

@@ -652,6 +652,7 @@ class XmlFileLoaderTest extends TestCase
             [
                 str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'OtherDir') => true,
                 str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'BadClasses') => true,
+                str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'SinglyImplementedInterface') => true,
             ]
         );
         $this->assertContains((string) $globResource, $resources);
@@ -684,6 +685,7 @@ class XmlFileLoaderTest extends TestCase
             [
                 str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'BadClasses') => true,
                 str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'OtherDir') => true,
+                str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'SinglyImplementedInterface') => true,
             ]
         );
         $this->assertContains((string) $globResource, $resources);
@@ -901,4 +903,50 @@ class XmlFileLoaderTest extends TestCase
 
         $this->assertSame('overridden', $container->get('bar')->quz);
     }
+
+    public function testSinglyImplementedInterfacesInMultipleResources()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new XmlFileLoader($container, new FileLocator(self::$fixturesPath.'/xml'));
+        $loader->load('singly_implemented_interface_in_multiple_resources.xml');
+
+        $alias = $container->getAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class);
+
+        $this->assertSame(Prototype\SinglyImplementedInterface\Adapter\Adapter::class, (string) $alias);
+    }
+
+    public function testNotSinglyImplementedInterfacesInMultipleResources()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new XmlFileLoader($container, new FileLocator(self::$fixturesPath.'/xml'));
+        $loader->load('not_singly_implemented_interface_in_multiple_resources.xml');
+
+        $this->assertFalse($container->hasAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class));
+    }
+
+    public function testNotSinglyImplementedInterfacesInMultipleResourcesWithPreviouslyRegisteredAlias()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new XmlFileLoader($container, new FileLocator(self::$fixturesPath.'/xml'));
+        $loader->load('not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias.xml');
+
+        $alias = $container->getAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class);
+
+        $this->assertSame(Prototype\SinglyImplementedInterface\Adapter\Adapter::class, (string) $alias);
+    }
+
+    public function testNotSinglyImplementedInterfacesInMultipleResourcesWithPreviouslyRegisteredAlias2()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new XmlFileLoader($container, new FileLocator(self::$fixturesPath.'/xml'));
+        $loader->load('not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias2.xml');
+
+        $alias = $container->getAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class);
+
+        $this->assertSame(Prototype\SinglyImplementedInterface\Adapter\Adapter::class, (string) $alias);
+    }
 }

src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php

@@ -415,6 +415,7 @@ class YamlFileLoaderTest extends TestCase
             false, [
                 str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'BadClasses') => true,
                 str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'OtherDir') => true,
+                str_replace(\DIRECTORY_SEPARATOR, '/', $prototypeRealPath.\DIRECTORY_SEPARATOR.'SinglyImplementedInterface') => true,
             ]
         );
         $this->assertContains((string) $globResource, $resources);
@@ -834,4 +835,50 @@ class YamlFileLoaderTest extends TestCase
         $this->assertInstanceOf(TaggedIteratorArgument::class, $iteratorArgument);
         $this->assertNull($iteratorArgument->getIndexAttribute());
     }
+
+    public function testSinglyImplementedInterfacesInMultipleResources()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('singly_implemented_interface_in_multiple_resources.yml');
+
+        $alias = $container->getAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class);
+
+        $this->assertSame(Prototype\SinglyImplementedInterface\Adapter\Adapter::class, (string) $alias);
+    }
+
+    public function testNotSinglyImplementedInterfacesInMultipleResources()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('not_singly_implemented_interface_in_multiple_resources.yml');
+
+        $this->assertFalse($container->hasAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class));
+    }
+
+    public function testNotSinglyImplementedInterfacesInMultipleResourcesWithPreviouslyRegisteredAlias()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias.yml');
+
+        $alias = $container->getAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class);
+
+        $this->assertSame(Prototype\SinglyImplementedInterface\Adapter\Adapter::class, (string) $alias);
+    }
+
+    public function testNotSinglyImplementedInterfacesInMultipleResourcesWithPreviouslyRegisteredAlias2()
+    {
+        $container = new ContainerBuilder();
+
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('not_singly_implemented_interface_in_multiple_resources_with_previously_registered_alias2.yml');
+
+        $alias = $container->getAlias(Prototype\SinglyImplementedInterface\Port\PortInterface::class);
+
+        $this->assertSame(Prototype\SinglyImplementedInterface\Adapter\Adapter::class, (string) $alias);
+    }
 }