feature #28571 [DependencyInjection] Improve ServiceLocatorTagPass service matching (codedmonkey)

This PR was squashed before being merged into the 4.2-dev branch (closes #28571).

Discussion
----------

[DependencyInjection] Improve ServiceLocatorTagPass service matching

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #26892
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/pull/10397

Allows omitting of keys for service locator arguments (it will automatically take over the original definition alias).

Commits
-------

1c1210a3e8 [DependencyInjection] Improve ServiceLocatorTagPass service matching

src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php

@@ -52,6 +52,12 @@ final class ServiceLocatorTagPass extends AbstractRecursivePass
             if (!$v instanceof Reference) {
                 throw new InvalidArgumentException(sprintf('Invalid definition for service "%s": an array of references is expected as first argument when the "container.service_locator" tag is set, "%s" found for key "%s".', $this->currentId, \is_object($v) ? \get_class($v) : \gettype($v), $k));
             }
+
+            if (\is_int($k)) {
+                unset($arguments[0][$k]);
+
+                $k = (string) $v;
+            }
             $arguments[0][$k] = new ServiceClosureArgument($v);
         }
         ksort($arguments[0]);

src/Symfony/Component/DependencyInjection/Tests/Compiler/ServiceLocatorTagPassTest.php

@@ -0,0 +1,131 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\DependencyInjection\Tests\Compiler;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\Compiler\ServiceLocatorTagPass;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\DependencyInjection\ServiceLocator;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestDefinition1;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestDefinition2;
+
+require_once __DIR__.'/../Fixtures/includes/classes.php';
+
+class ServiceLocatorTagPassTest extends TestCase
+{
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\InvalidArgumentException
+     * @expectedExceptionMessage Invalid definition for service "foo": an array of references is expected as first argument when the "container.service_locator" tag is set.
+     */
+    public function testNoServices()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('foo', ServiceLocator::class)
+            ->addTag('container.service_locator')
+        ;
+
+        (new ServiceLocatorTagPass())->process($container);
+    }
+
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\InvalidArgumentException
+     * @expectedExceptionMessage Invalid definition for service "foo": an array of references is expected as first argument when the "container.service_locator" tag is set, "string" found for key "0".
+     */
+    public function testInvalidServices()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('foo', ServiceLocator::class)
+            ->setArguments(array(array(
+                'dummy',
+            )))
+            ->addTag('container.service_locator')
+        ;
+
+        (new ServiceLocatorTagPass())->process($container);
+    }
+
+    public function testProcessValue()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('bar', CustomDefinition::class);
+        $container->register('baz', CustomDefinition::class);
+
+        $container->register('foo', ServiceLocator::class)
+            ->setArguments(array(array(
+                new Reference('bar'),
+                new Reference('baz'),
+                'some.service' => new Reference('bar'),
+            )))
+            ->addTag('container.service_locator')
+        ;
+
+        (new ServiceLocatorTagPass())->process($container);
+
+        /** @var ServiceLocator $locator */
+        $locator = $container->get('foo');
+
+        $this->assertSame(CustomDefinition::class, \get_class($locator('bar')));
+        $this->assertSame(CustomDefinition::class, \get_class($locator('baz')));
+        $this->assertSame(CustomDefinition::class, \get_class($locator('some.service')));
+    }
+
+    public function testServiceWithKeyOverwritesPreviousInheritedKey()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('bar', TestDefinition1::class);
+        $container->register('baz', TestDefinition2::class);
+
+        $container->register('foo', ServiceLocator::class)
+            ->setArguments(array(array(
+                new Reference('bar'),
+                'bar' => new Reference('baz'),
+            )))
+            ->addTag('container.service_locator')
+        ;
+
+        (new ServiceLocatorTagPass())->process($container);
+
+        /** @var ServiceLocator $locator */
+        $locator = $container->get('foo');
+
+        $this->assertSame(TestDefinition2::class, \get_class($locator('bar')));
+    }
+
+    public function testInheritedKeyOverwritesPreviousServiceWithKey()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('bar', TestDefinition1::class);
+        $container->register('baz', TestDefinition2::class);
+
+        $container->register('foo', ServiceLocator::class)
+            ->setArguments(array(array(
+                'bar' => new Reference('baz'),
+                new Reference('bar'),
+            )))
+            ->addTag('container.service_locator')
+        ;
+
+        (new ServiceLocatorTagPass())->process($container);
+
+        /** @var ServiceLocator $locator */
+        $locator = $container->get('foo');
+
+        $this->assertSame(TestDefinition1::class, \get_class($locator('bar')));
+    }
+}