Templated ServiceLocator to be used for tagged services

src/Stubs/5/Component/DependencyInjection/ServiceLocator.stubphp

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+<?php
+
+namespace Symfony\Component\DependencyInjection;
+
+use Psr\Container\ContainerExceptionInterface;
+use Psr\Container\NotFoundExceptionInterface;
+use Symfony\Component\DependencyInjection\Exception\RuntimeException;
+use Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException;
+use Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
+use Symfony\Contracts\Service\ServiceLocatorTrait;
+use Symfony\Contracts\Service\ServiceProviderInterface;
+use Symfony\Contracts\Service\ServiceSubscriberInterface;
+
+/**
+ * @template T
+ */
+class ServiceLocator implements ServiceProviderInterface
+{
+
+    /**
+     * @return T
+     */
+    public function get($id);
+
+    /**
+     * @return array<string, string>
+     */
+    public function getProvidedServices(): array;
+}

src/Stubs/6/Component/DependencyInjection/ServiceLocator.stubphp

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+<?php
+
+namespace Symfony\Component\DependencyInjection;
+
+use Psr\Container\ContainerExceptionInterface;
+use Psr\Container\NotFoundExceptionInterface;
+use Symfony\Component\DependencyInjection\Exception\RuntimeException;
+use Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException;
+use Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
+use Symfony\Contracts\Service\ServiceLocatorTrait;
+use Symfony\Contracts\Service\ServiceProviderInterface;
+use Symfony\Contracts\Service\ServiceSubscriberInterface;
+
+/**
+ * @template T
+ */
+class ServiceLocator implements ServiceProviderInterface
+{
+
+    /**
+     * @return T
+     */
+    public function get($id)
+    {}
+
+    /**
+     * @return array<string, string>
+     */
+    public function getProvidedServices(): array;
+}

tests/acceptance/acceptance/ServiceLocator.feature

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+@symfony-5 @symfony-6
+Feature: ServiceLocator
+
+  Background:
+    Given I have Symfony plugin enabled
+
+  Scenario: ServiceLocator will return tagged service
+    Given I have the following code
+      """
+      <?php
+
+      interface StrategyInterface{}
+
+      use Symfony\Component\DependencyInjection\ServiceLocator;
+
+      class MyService
+      {
+          /** @var ServiceLocator<StrategyInterface> $strategies */
+          private ServiceLocator $strategies;
+
+          /** @param ServiceLocator<StrategyInterface> $strategies */
+          public function __construct(ServiceLocator $strategies)
+          {
+              $this->strategies = $strategies;
+          }
+
+          public function doSomethingWithStrategy(): void
+          {
+              $strategy = $this->strategies->get('random_string');
+              /** @psalm-trace $strategy */
+          }
+      }
+      """
+    When I run Psalm
+    Then I see these errors
+      | Type  | Message                                     |
+      | Trace | $strategy: StrategyInterface                |
+    And I see no other errors
+
+  Scenario: Fixed the return type of getProvidedServices()
+    Given I have the following code
+      """
+      <?php
+
+      interface StrategyInterface{}
+
+      use Symfony\Component\DependencyInjection\ServiceLocator;
+
+      class MyService
+      {
+          /** @var ServiceLocator<StrategyInterface> $strategies */
+          private ServiceLocator $strategies;
+
+          /** @param ServiceLocator<StrategyInterface> $strategies */
+          public function __construct(ServiceLocator $strategies)
+          {
+              $this->strategies = $strategies;
+          }
+
+          public function getAll(): void
+          {
+              $names = $this->strategies->getProvidedServices();
+              /** @psalm-trace $names */
+          }
+      }
+      """
+    When I run Psalm
+    Then I see these errors
+      | Type  | Message                                     |
+      | Trace | $names: array<string, string>               |
+    And I see no other errors