Make ServiceLocatorInterface#get() generic

psalm-baseline.xml

@@ -211,6 +211,11 @@
       <code><![CDATA[MixedPluginManager]]></code>
     </UnusedClass>
   </file>
+  <file src="test/StaticAnalysis/ServiceLocatorInterfaceConsumer.php">
+    <UnusedClass>
+      <code><![CDATA[ServiceLocatorInterfaceConsumer]]></code>
+    </UnusedClass>
+  </file>
   <file src="test/StaticAnalysis/ServiceManagerConfiguration.php">
     <UnusedClass>
       <code><![CDATA[ServiceManagerConfiguration]]></code>

src/PluginManagerInterface.php

@@ -29,7 +29,7 @@ public function validate(mixed $instance): void;
     /**
      * @template TRequestedInstance extends InstanceType
      * @psalm-param class-string<TRequestedInstance>|string $id Service name of plugin to retrieve.
-     * @psalm-return ($id is class-string ? TRequestedInstance : InstanceType)
+     * @psalm-return ($id is class-string<TRequestedInstance> ? TRequestedInstance : InstanceType)
      * @throws Exception\ServiceNotFoundException If the manager does not have
      *     a service definition for the instance, and the service is not
      *     auto-invokable.
@@ -43,7 +43,7 @@ public function get(string $id): mixed;
      *
      * @template TRequestedInstance extends InstanceType
      * @psalm-param string|class-string<TRequestedInstance> $name
-     * @psalm-return ($name is class-string ? TRequestedInstance : InstanceType)
+     * @psalm-return ($name is class-string<TRequestedInstance> ? TRequestedInstance : InstanceType)
      * @throws Exception\ServiceNotFoundException If no factory/abstract
      *     factory could be found to create the instance.
      * @throws Exception\ServiceNotCreatedException If factory/delegator fails

src/ServiceLocatorInterface.php

@@ -8,14 +8,15 @@
 use Laminas\ServiceManager\Exception\ServiceNotFoundException;
 use Psr\Container\ContainerExceptionInterface;
 use Psr\Container\ContainerInterface;
+use Psr\Container\NotFoundExceptionInterface;
 
 /**
  * Interface for service locator
  */
 interface ServiceLocatorInterface extends ContainerInterface
 {
     /**
-     * Build a service by its name, using optional options (such services are NEVER cached).
+     * Builds a service by its name, using optional options (such services are NEVER cached).
      *
      * @template T of object
      * @param  string|class-string<T> $name
@@ -27,4 +28,15 @@ interface ServiceLocatorInterface extends ContainerInterface
      * @throws ContainerExceptionInterface If any other error occurs.
      */
     public function build(string $name, ?array $options = null): mixed;
+
+    /**
+     * Finds an entry of the container by its identifier and returns it.
+     *
+     * @template T of object
+     * @param string|class-string<T> $id
+     * @psalm-return ($id is class-string<T> ? T : mixed)
+     * @throws ContainerExceptionInterface Error while retrieving the entry.
+     * @throws NotFoundExceptionInterface No entry was found for **this** identifier.
+     */
+    public function get(string $id);
 }

src/ServiceManager.php

@@ -202,6 +202,7 @@ public function get(string $id): mixed
         // We start by checking if we have cached the requested service;
         // this is the fastest method.
         if (isset($this->services[$id])) {
+            /** @psalm-suppress MixedReturnStatement Yes indeed, service managers can return mixed. */
             return $this->services[$id];
         }
 
@@ -217,6 +218,8 @@ public function get(string $id): mixed
             if ($sharedService) {
                 $this->services[$id] = $service;
             }
+
+            /** @psalm-suppress MixedReturnStatement Yes indeed, service managers can return mixed. */
             return $service;
         }
 
@@ -234,6 +237,8 @@ public function get(string $id): mixed
         // If the alias is configured as a shared service, we are done.
         if ($sharedAlias) {
             $this->services[$id] = $this->services[$resolvedName];
+
+            /** @psalm-suppress MixedReturnStatement Yes indeed, service managers can return mixed. */
             return $this->services[$resolvedName];
         }
 
@@ -247,6 +252,7 @@ public function get(string $id): mixed
             $this->services[$id]           = $service;
         }
 
+        /** @psalm-suppress MixedReturnStatement Yes indeed, service managers can return mixed. */
         return $service;
     }
 

test/StaticAnalysis/ServiceLocatorInterfaceConsumer.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LaminasTest\ServiceManager\StaticAnalysis;
+
+use DateTimeImmutable;
+use Laminas\ServiceManager\ServiceLocatorInterface;
+
+use function assert;
+
+final class ServiceLocatorInterfaceConsumer
+{
+    public function canInferTypeFromGet(): void
+    {
+        $serviceProvider = $this->getServiceProvider();
+
+        $date = $serviceProvider->get(DateTimeImmutable::class);
+        echo $date->format('Y-m-d H:i:s');
+
+        $value = $serviceProvider->get('foo');
+        assert($value === 'bar');
+    }
+
+    public function canInferTypeFromBuild(): void
+    {
+        $serviceProvider = $this->getServiceProvider();
+
+        $date = $serviceProvider->build(DateTimeImmutable::class);
+        echo $date->format('Y-m-d H:i:s');
+
+        $value = $serviceProvider->build('foo');
+        assert($value === 'bar');
+    }
+
+    private function getServiceProvider(): ServiceLocatorInterface
+    {
+        $services = [
+            'foo'                    => 'bar',
+            DateTimeImmutable::class => new DateTimeImmutable(),
+        ];
+        return new class ($services) implements ServiceLocatorInterface {
+            public function __construct(private readonly array $services)
+            {
+            }
+
+            public function has(string $id): bool
+            {
+                return isset($this->services[$id]);
+            }
+
+            public function build(string $name, ?array $options = null): mixed
+            {
+                /** @psalm-suppress MixedReturnStatement Yes indeed, can return mixed. */
+                return $this->services[$name] ?? null;
+            }
+
+            public function get(string $id): mixed
+            {
+                /** @psalm-suppress MixedReturnStatement Yes indeed, can return mixed. */
+                return $this->services[$id] ?? null;
+            }
+        };
+    }
+}