MNT Update generic types for Injector

- IDEs don't resolve the conditional return types phpstan provides, remove the conditional return types and add them as stubs in order to pass the test cases

src/Core/Injector/Injector.php

@@ -967,13 +967,12 @@ class Injector implements ContainerInterface
      * @throws NotFoundExceptionInterface  No entry was found for **this** identifier.
      *
      * @template T of object
-     * @param class-string<T> $name The name of the service to retrieve. If not a registered
+     * @param class-string<T>|string $name The name of the service to retrieve. If not a registered
      * service, then a class of the given name is instantiated
      * @param bool $asSingleton If set to false a new instance will be returned.
      * If true a singleton will be returned unless the spec is type=prototype'
      * @param array $constructorArgs Args to pass in to the constructor. Note: Ignored for singletons
-     * @return mixed Instance of the specified object
-     * @phpstan-return ($name is class-string<T> ? T : mixed) Instance of the specified object
+     * @return T|mixed Instance of the specified object
      */
     public function get($name, $asSingleton = true, $constructorArgs = [])
     {
@@ -1128,10 +1127,9 @@ class Injector implements ContainerInterface
      * Additional parameters are passed through as
      *
      * @template T of object
-     * @param class-string<T> $name
+     * @param class-string<T>|string $name
      * @param mixed ...$argument arguments to pass to the constructor
-     * @return mixed A new instance of the specified object
-     * @phpstan-return ($name is class-string<T> ? T : mixed) A new instance of the specified object
+     * @return T|mixed A new instance of the specified object
      */
     public function create($name, $argument = null)
     {
@@ -1144,10 +1142,9 @@ class Injector implements ContainerInterface
      * Creates an object with the supplied argument array
      *
      * @template T
-     * @param class-string<T> $name Name of the class to create an object of
+     * @param class-string<T>|string $name Name of the class to create an object of
      * @param array $constructorArgs Arguments to pass to the constructor
-     * @return mixed
-     * @phpstan-return ($name is class-string<T> ? T : mixed)
+     * @return T|mixed
      */
     public function createWithArgs($name, $constructorArgs)
     {

tests/php/Type/InjectorTypeTest.php

@@ -24,4 +24,12 @@ class InjectorTypeTest extends TypeInferenceTestCase
     {
         $this->assertFileAsserts($assertType, $file, ...$args);
     }
+
+    /**
+     * @return string[]
+     */
+    public static function getAdditionalConfigFiles(): array
+    {
+        return [__DIR__ . '/phpstan.neon.dist'];
+    }
 }

tests/php/Type/phpstan.neon.dist

@@ -1,3 +1,5 @@
 parameters:
-	bootstrapFiles:
-		- phpstan-bootstrap.php
+    bootstrapFiles:
+        - phpstan-bootstrap.php
+    stubFiles:
+        - stubs/SilverStripe/Core/Injector/Injector.stub

tests/php/Type/stubs/SilverStripe/Core/Injector/Injector.stub

@@ -0,0 +1,62 @@
+<?php
+
+namespace SilverStripe\Core\Injector;
+
+use Psr\Container\ContainerInterface;
+
+class Injector implements ContainerInterface
+{
+    /**
+     * Get a named managed object
+     *
+     * Will first check to see if the item has been registered as a configured service/bean
+     * and return that if so.
+     *
+     * Next, will check to see if there's any registered configuration for the given type
+     * and will then try and load that
+     *
+     * Failing all of that, will just return a new instance of the specified object.
+     *
+     * @throws NotFoundExceptionInterface  No entry was found for **this** identifier.
+     *
+     * @template T of object
+     * @param class-string<T>|string $name The name of the service to retrieve. If not a registered
+     * service, then a class of the given name is instantiated
+     * @param bool $asSingleton If set to false a new instance will be returned.
+     * If true a singleton will be returned unless the spec is type=prototype'
+     * @param array $constructorArgs Args to pass in to the constructor. Note: Ignored for singletons
+     * @return T|mixed Instance of the specified object
+     * @phpstan-return ($name is class-string<T> ? T : mixed)
+     */
+    public function get($name, $asSingleton = true, $constructorArgs = [])
+    {
+    }
+
+    /**
+     * Similar to get() but always returns a new object of the given type
+     *
+     * Additional parameters are passed through as
+     *
+     * @template T of object
+     * @param class-string<T>|string $name
+     * @param mixed ...$argument arguments to pass to the constructor
+     * @return T|mixed A new instance of the specified object
+     * @phpstan-return ($name is class-string<T> ? T : mixed) A new instance of the specified object
+     */
+    public function create($name, $argument = null)
+    {
+    }
+
+    /**
+     * Creates an object with the supplied argument array
+     *
+     * @template T
+     * @param class-string<T>|string $name Name of the class to create an object of
+     * @param array $constructorArgs Arguments to pass to the constructor
+     * @return T|mixed
+     * @phpstan-return ($name is class-string<T> ? T : mixed)
+     */
+    public function createWithArgs($name, $constructorArgs)
+    {
+    }
+}